pdd1

Professional Development Diploma
(PDD Building Cons.)
Student: Brendan Teasdale,
Building Conservation Masterclasses (BCM)

This essay has been prepared by
Brendan Teasdale for the completion of
the PDD Building Cons, Diploma, and
describes my journey made during
2010 to 2015.
The courses at West Dean have given me the correct tools in order to
commence and carry out my current role as a conservation mason and
my path to saving buildings at risk. This essay endeavors to explain this
by linking my experience directly to the training I received through the
Building Conservation Master classes. As I guide you through my
journey hopefully it will become evident that with the correct guidance
and teaching, good things can actually come true.
2 3

Contents
1. Master Classes attended during 2010 and 2015.
pages 6 - 7
2. Introduction.
pages 8 - 9
3. My Journal- My PDD, Master Classes during 2010-2015.
pages 10 - 37
4. Conclusion
pages 38 - 41
5. Appendices/Case studies.
pages 42 - 53
4 5

Professional Development Diploma (PDD Building Cons.)
1. e Structural Repair of Historic Buildings,
21-24 September 2009.
2. e Historic Interior, Commissioning and Managing Conservation Research
8-10 February 2010.
3. Mortars for Repair and Conservation
5-8 November 2012.
4. Conservation and Repair of Brick and Flint Masonry
22-25 April 2013.
5. Masonry Cleaning
24-27 June 2013. (Selected)
6. Conservation and Repair of Stone Masonry
30th Sept-3rd Oct, 2013.
7. Conservation and Repair of Timber
14-17 October 2013.
8. Conservation of Architectural Detail and Surfaces
31March-3rd April (Selected)
9. Specifying Conservation Works
9-12 February 2015 (Selected)
10. Conservation and Repair of Plasters and Renders
30 March-2nd April 2015.
1 List of Master
Classes Attended
6 7

Professional Development Diploma (PDD Building Cons.)Professional Development Diploma (PDD Building Cons.)
Introduction2 This essay has been prepared by Brendan Teasdale for the
completion of the PDD Building Cons Diploma and describes
my journey made during 2010 to 2015.
Image: Brendan
Teasdale at Tymenouth
Station. Caving with
Portland Limestone.
8 9

Ray Stockdale seemed like the only person that
I could talk to or go to for advice. Ray also
used to tell me stories of the old days when
ancient monuments were consolidated with
cement mortars and neat cement grouts.At first
I found this hard to take in and I could not
believe that an organization like English
Heritage, then known as The Historic
Buildings and Monuments Commission(1),
could be responsible for what seemed at the
time like a deliberate destruction of our
heritage. I always thought that Hadrian’s Wall
was original, not rebuilt to a large degree and
was surprised to hear that most of it was
actually dug up from the overgrown vegetation
and rebuilt using cements(2) English Heritage
looks after 8 miles of Hadrian’s Wall 80-90%
approximately of the wall has been recorded
taken down and rebuilt(3). Ray went on to
inform me that if the buildings that he managed
in the early days had not been consolidated
with cement grouts some parts of the buildings
may not have survived.
Today ancient monuments are looked after,
monitored and cared for by English Heritage.
Nevertheless it wasn’t just English Heritage
who made mistakes, we see the same mistakes
everywhere we look today. Manufactured
cements seem to be at the heart of all mistakes
if we are solely talking about the conservation
of lime mortar built structures. It is however
easy to see how cement became popular, it is
easy to apply and it is less labor intensifying
therefore it is a very cost effective alternative
material. Although come on let’s be honest
cement is in fact a wonderful material
nevertheless it needs to be used on other types
of buildings that can accommodate it and will
not be detrimental to the building in question
that requires sensitive lime mortar
conservation.
It seems the more you look into past and
current conservation mistakes the more
questions you need to ask and believe me there
are not many people that can answer them, so
this was my motivation for attending the PDD
Building Master classes at West Dean College.
Pre-2009, I became aware of the past mistakes that would later on motivate me and
lead me to West Dean College. Today I am fully aware of the conservation principles
taught to me by West Dean College but pre-2009 there was no one pushing me to
better myself, maybe this was because of the lack of knowledge in the North when it
came to conservation. At the time I felt unchallenged and I was simply trusted to a
degree, being left to get on with the tasks that had been set out in the job specification.
My Journal- My PDD
Master Classes During 2010-2015
3
Image from Coquet Island
“Leading up to my decision to enroll on my journey with West
Dean College I often asked myself the question;”
Past Mistakes
10 11

Brendan Craving at Linisdfarne
“Can one man really
make a difference?”
12 13

Most of our historic coastal monuments in Northumberland suffer the harsh salt
air weather conditions, where the masonry is exposed to the aggressive swirling
action of the wind and the freeze thaw process which in turn creates accelerated
erosion to the masonry known as Alveolar Erosion.
Ray Stockdale, provided the following definition of Alveolar Erosion “Alveolar erosion is often
associated with maritime locations, and is typified by the formation of smooth hemispherical
depressions in the surface of the stone. The depressions can become so numerous that they join
together forming a honeycomb-like appearance. This process is believed to occur through the
formation of salt-induced disaggregation pockets which then weather perfectly into cavities (or
aveoles). This form of decay is usually associated in areas experiencing wind turbulence which
causes both accelerated drying and salt crystallization as well as physical wind erosion.
Depressions form and they are gradually enlarged to the point where it causes a micro-
environment within it. Within this environment air pressure, drying rates, disaggregation and
abrasive micro-eddying will differ from unaffected areas further enhancing the erosion of the
depression”(4).
The erosion is further exasperated by the re-pointing and grouting works carried out during the
early 1920’s to 1980’s by English Heritage*
The direct labor team known then as The Ministry
of Public Buildings and Works (MPBW) and later known as The Department of the Environment
(Ancient Monuments Department).
The cement grout and pointing works carried out during
these times caused the buildings to retain water within
the fabric of the inner core (Hearting) where further
damage occurred through the aggressive freeze thaw
processes.
*English Hertiage changed its name in recently to Historic England. Before 1980 it has assumed many names including The Ministry of Public Buildings and
Works. For continuity of this essay I will refer to it as English Hertiage thoughtout.
Conservation in the North
Image showing Alveolar Erosion at Coquet Island
image showing Alveolar Erosion
14 15

Scotch Pointing or Sterling Grit depending on
where you lived got its name from when
English Heritage (North England) was
managed by their Edinburgh office. This was
the standard mix used then on most of our
coastal and inland monuments, and although it
has caused some problems it is also believed
that if it had not been used when it did we may
have less of our heritage intact today. The
main reason lime was not used was due to the
lack of knowledge and confidence of lime in
conservation.
Cement was fashionable, cheap and easy to
use, however it was also detrimental to ancient
monuments.
In the mortar demonstrations at West Dean
College we were shown several pieces cured
of mortar, some recent and others from the core
work of Roman ruins. I was especially
interested in the Roman mortar yet astonished
to see that when Colin Burns, Principal Tutor
at West Dean College, slammed it on to the
bench it remained intact, it also seemed
incredibly hard and unbreakable.
Scotch Pointing
Scotch pointing is basically a mixture of 1 measure of cement (OPC) and two aggregate which
contains some large aggregate particles(5). This essentially is concrete and is very hard to remove
from the beds and joints of the stones. Be aware though because behind most Scotch Pointing
lies something even harder, a mixture of neat cement grout. This cement grout can penetrate up
to 150mm into the building from the surface and was pumped into the building fabric using a
grouting pump.
All 3 images showing Scotch Pointing
16 17

Removing Scotch Pointing proves very difficult and requires highly skilled operatives. This
hard cement based material needs to be removed but without causing damage to the structure.
The procedure would be to remove the grit surface with a tungsten chisel first and then drill a
series of holes at 10-15mm intervals through the beds and joints. This creates space within the
mortar joint and allows the conservator to break out the hard mortar with a mallet and a tungsten
tipped chisel, and this also applies to the cement grout.
We would only consider removing this
material in joints of a greater width than 5mm
as it is considered too risky and could lead to
damaging the stones. Not all of the grout can
be successfully removed because in some cases
the facing stones run the risk of collapse.
To compensate this we drill right through the
cement grout and into the original mortar, this
allows for some moisture evaporation within
the core of the structure. When drilling through
the cement grout we normally watch for a color
change in the dust produced from the drilling
action, this usually informs us that we are
drilling into the lime mortar and not the stone
units themselves.
I also learned that lime mortars carry on curing over time and
can get very hard yet on the other hand still breathable. Unlike
Scotch Pointing and Cement Grout both are extremely hard
material and do not breath.
Images showing Scotch Pointing being removed
18 19

The sculptural effects of Alveolar Erosion can take its toll on our coastal buildings, this type of
erosion can be minimized by filling in the alveolar depressions with color matching mortars.
Repairs of this nature improves the ability of the stones to shed wind flow and water.
Careful consideration is given when mortar repairs are to be carried out to this type of stone
decay, under no circumstances did we want to change the overall appearance of the stones. Most
of our coastal historic properties are ruins and we don’t want to change the aesthetics of this,
basically they need to remain ruins. One must first consider filling the Alveolar depression only
where needed and ensure that any repairs are minimum so that the stones still show signs of
erosion.
At West Dean College it was great to see mortars being prepared, we even got the chance to
make our own mortars choosing the binders and aggregates ourselves.
Before attending West Dean College, I had some minimal experience on mortar repair work to
stones, the course taught me to prepare the stone first to receive the repair mortar. Firstly you
will need to scrape off any moss or algae and at the same time remove any friable dust from the
stone surface where the repair is to be carried out. Then you need to soak the repair area on the
substraight to control suction, there should be no standing water on the stone but
it should remain damp during the repair and curing of the repair mortar.
Before the mortar is applied to the stone we use a liquefied coat of mortar to apply to the stone
surface. This is called a tack coat or a pricking up coat. The tack coat ensures the mortar adheres
well to the surface of the stone. As shown in the image below.
To follow this we mixed some mortar using an NHL 2 lime binder and sharp well graded sand,
no color pigment was added, instead we selected sands that resembled the actual stone color
that we were repairing. Some natural colored pigments can discolor over time so we try not to
rely too much on pigments. Most mortar repairs require a build up of mortar in layers especially
where the mortar repairs are deep. Clay armatures in the shape of a ‘T’ can also be used to help
with deep mortared areas. Where mortar does require a build up of layers we normally sieve the
sands for the top coat, this removes the larger particles of sand that are sometimes unwanted.
Mortar for Pointing & Repairs
20 21

Professional Development Diploma (PDD Building Cons.) Professional Development Diploma (PDD Building Cons.)
During the Master Classes at West Dean
College we learnt how to cure mortar. I have
seen many a time when contractors don’t look
after their mortar or don’t cover it up to protect
it. When we use mortar for repairs to historic
structures we need to bear in mind that we are
not building a solid wall where plenty of
moisture is held within the core of the wall to
help with the curing. Conservation repairs with
mortar whether it is pointing or a stone repair,
requires build up applications and sometimes
in small isolated areas. Bearing this in mind we
need to be extra careful and essentially wrap
the repair areas up (literally) in cotton wool.
During my time at West Dean College a lot of
emphasis was put on mortars and they were
repeated on a lot, this for me was vital. Lime
mortars mixed and applied in the correct way
can produce not only the required aesthetic
looks but will preserve the building for future
generations.
The Master Classes have paved the way for me to adopt a much
broader understanding and develop my technical skills to ensure
that I have the knowledge to take me forward.
Inserting Galleting into the mortar is a very good way to cut down on volume of mortar usage,
this is not for financial reasons though, the less mortar, the less chance of your repair mortar
shrinking. The Galleting stones will also serve to help underpin other stones within the masonry
structure. As shown in the images to the left.
22 23

Professional Development Diploma (PDD Building Cons.) Professional Development Diploma (PDD Building Cons.)
Malcolm Starr was the course leader on the Specifying Conservation Works, Master Class
This course studied initial surveys, project planning and ‘’correct specification’’. As a
Conservation Mason I don’t get to specify my own repair works and I often wondered why
specifications were so vague and in some cases incorrect. Coming into this industry I thought
that architects, surveyors etc would all know what to write when specifying the works on historic
buildings. The fact is some don’t and this can be just as dangerous as the builder that does not
know what lime mortar is, as he applies his bucket of cement. I am also growing increasingly
disappointed when so called conservation architects class me as a builder, this is their first
mistake. Not knowing the difference, is the first mistake and Malcolm did his best to try to
preach this to the architects and surveyors in the class.
Lime mortar, providing it is weaker or more breathable than the stone substrate, will draw
moisture away from the stone units within the wall. The moisture is driven off into the
atmosphere through the mortar joints and beds. This kind of information tends to be left out of
specifications and relies totally on West Dean College to teach it, and is also down to experience.
Specifications
Specifications in the North seem to only advise we use Natural Hydraulic Lime (NHL) usually
NHL 3.5 and specifications always advise we use 3 sand to 1 binder. Hydraulic lime binders are
classed as NHL2, NHL3.5, and NHL5, the numbers are classed on crushing strengths so a NHL5
would be classed as having a crushing strength of 5 Kilo Newton’s (mega Pascal’s) per
millimeter squared . This however is at 28 days but lime does not reach its full strength until
approximately 90 days so an NHL5 could actually become the quevelent of an NHL10 or 15
after this time (6).
When carrying out conservation work on a historic structure we don’t need crushing strengths
as we are only intending to carry out repair work. Therefore we don’t need to use high crushing
strength limes. For projects in the North of England, hydraulic limes have worked best due to
the more severe weather conditions. In my view if hydraulic limes are used then an NHL2 should
suffice.
A successful mortar depends on a lot of things already mentioned above. However there are
other vital things to consider. These include bulking and void ratios. Bulking of sand normally
means that the sand is damp. Damp sand can increase its volume dramatically. To avoid bulking,
sand should be stored in dry conditions or at least covered up. Lime binders can also bulk when
disturbed from their bags. Furthermore the relative bulking density should be printed on the
side of the bags.
In the North of England I am currently using two types of sand for conservation work, Styford
Sharp and Thornbrough Soft. These sands have been used for a number of years by English
Heritage and their conservators. They are a very good match for the type of sand stone used in
historic masonry. During the masonry courses at West Dean College we learnt how to measure
void ratio in sands. I have now applied the same test to both the sands mentioned above and
discovered that Styford Sharp has a 37% void ratio and Thornbrough Soft has a 45% void ratio.
Bearing this in mind where do we get this three to one ratios
from in today’s specifications?
image showing gap left once Scotch poitning has been removed
24 25

A good guide
10 things to consider when applying lime mortars for conservation.
1. Prepare the surface of the stone or rake out the mortar joint to the correct depth.
2. Remove all traces of dust, algae.
3. Dampen down the substrate to control suction.
4. Carefully select and mix mortars for pointing or stone repairs.
5. Apply the mortar, don’t use mortars that have too much water added.
6. Apply the mortar, sometimes in layers building the repair up.
7. Use galleting to cut down on mortar avoiding shrinkage.
8. Apply the mortar with care and see the whole task through to completion, and
be sympathetic to the building you are working on. Including paring back the
mortar and striking the surface of the mortar with a churn brush.
9. Cover all mortar up for up to one week and dampen down when necassary to
avoid rapid drying out.
10. Finally remember, what ever the weather, rain, wind, cold, hot, sun, and just
about everything else will destroy your mortar, so be disciplined.
Shelter Coats
Before attending West Dean I have to admit I was not quite carrying this task out correctly. More
oen than not, it was pointless following the project specification due to a lack of information.
Like everyone else in Northumberland, a shelter coat was a bit like a lime wash but more of a
watered down pointing mortar than anything else.
Previously shelter coats carried out would result in the stone becoming stained with binder. I see
now that this in fact was not a shelter coat but a slurry of mortar used to destroy the aesthetics
of the stone surface.
West Dean College demonstrated the application of a shelter coat. Water and lime binder were
mixed and then brushed across the surface of a piece of limestone. e lime binder was then
worked into the surface of the stone and then the residue wiped oﬀ with a damp sponge. To my
amazement there were no traces of binder on the surface of the stone, and only the small voids
were filled out. ese results were clearly seen viewed under a magnifying glass.
26 27

Most 18th and 19th century stone buildings were designed to control the flow of
water over their surface, this includes many historic structures before this time.
Projecting stones i.e. cornices and string courses installed into the building help
to shed off water rather than let water run down the face of the wall.
These projecting stones are normally found on chimneys, and at every floor level of a building
at horizontal bands. When this works properly it helps to contribute to a dry structure.
Often stones are replaced because ascetically they do not look right but we should always
remember that the rule of conservation is minimum intervention.
As Lu Allington-Jones supports
“The premise lies in considering all
possibilities and then choosing the option with
the lowest impact”(7)
The difficulty in deciding where to start replacing eroded stone is matched by an equal
difficulty in deciding where to stop. Unless stone has become loose or fractured, stone can
erode to a considerable depth before causing structural problems that need attention.
1. Authenticity, would the retaining of original stone preserve the buildings integrity and
character?
2. Aesthetic, the appearance of the building, does it depend on retaining the marks of
time?
3. Structural soundness, will the building collapse or will there be serious failures if
stone replacement has not been decided?
4. Functional, is the building still performing in the way it was meant to be?
5. And has the building stone lost its architectural detailing (8)
The Trouble with Modern Stone These five considerations need to be noted
before deciding to replace masonry units within
a historic structure.
28 29

When an historic structure is badly decayed and its masonry units are well worn it can prove
very difficult to consider new stone additions. In some cases it is necessary to retain the existing
stone. Nevertheless if there are no existing stones and there is a risk of structural failure
occurring we must consider building up the core work but setting this back so as not to build
out to the building line. For instance I personally think that if we are working on an ancient ruin
then we must try not to be tempted to introduce new stones. By building up the core work this
will retain the authentic look of the building; after all if it is a ruin then it should remain a ruin.
Images of Tynemouth Priory with a modern stone applied to a historic ruin.
In my view the problem with new stone replacement is the way it arrives from the supplier,
perfectly sawn six sided. I presented both of these actual photos to Colin Burns when I attended
the Conservation of Architectural Detail and Surfaces master class, at West Dean College. This
presented the opportunity for Colin Burns to discuss this type of problem with the students on
the course. It was the response I was hoping to get to be honest. I suppose I needed it confirming
to me that this was in fact the incorrect way to carry out proper conservation.
The opposite picture shows how unsympathetic new stone can be to the existing structure when
cutting and preparation has not been carried out by the correct method. The stones were sawn
six sided and brought to site by the stone supplier. I tooled the stones myself and my team
installed them making sure that they were well doweled in to the core work with stainless steel
and threaded bar. It wasn’t until the scaffold and netting came down that I realized that the new
stones stuck out like two beacons. Realizing that this was not an appropriate way to install new
stones into a historic structure I offered to erect a scaffold at my own cost to replace them, but
English Heritage said that was what they wanted and they had to be left in place.
So what does this tell us about modern
thinking and the shear lack of knowledge
within our industry?
When you select a stone for replacement it needs to be more or less quarried and dressed as it
would have been back in the day of original construction. Normally cut from a larger block,
rough cut and then squared, you should end up with a rough hewn surface. This kind of
preparation for new stones is aesthetically pleasing and if you have made the decision to replace
stone it is the most sympathetic way to install new stone on an historic structure.
Bearing in mind the above points I realize now
that in my five years of conservation I too have
made some mistakes, and since attending the
PDD Building Master Classes at West Dean
College I aim to put this right.
The biggest learning curve here for me was the
new masonry units that I hand shaped and
carved for the replacement stones on
Tynemouth Priory shown in both images
below. In my view I don’t think we made right
decision for this type of building, a ruin to a
large degree. However on the contrary the
replacement stones were not considered wrong
by the client English Heritage, nor did they
come under any criticism by others.
30 31

The image above shows a large lintel above a door opening, and the image
top right shows the external wall of a stair turret, both at Tynemouth
Priory. The stones are fitted dry first to see if they fit correctly and shown
in situ as per the original building line. This is not quite as drastic as the
images on the previous page and could possibly be correct as far as new
stone replacement is concerned. The curved stones used here were worked
on site and were not bought in from a supplier sawn to shape. We distress
them on site before building them into the existing weathered masonry.
The image at the bottom right shows the previous mason’s attempts
at Tynemouth Priory which lead to me replacing them with new
stone. There are three things wrong with this type of intervention,
for a start the stone is recessed and built in behind the exiting
weathered masonry, the stone is sawn faced and has not been worked
traditionally, and last of all the mortar work in the bedding of the
stones is fairly bad at best.
32 33

The first course I attended was named the Structural Repair of Historical Buildings. This course
was the first in a series to follow and my journey into conservation techniques of historic
buildings and sites. During the course I learnt about the structural issues surrounding historic
buildings and ancient monuments. The course in brief gave me a better understanding on
structural issues within the masonry fabric of a historic building and made me more aware of
past structural interventions. I am not a structural engineer, however I now fully appreciate the
difficulty when there is a structural issue within a historic building. For example it is easy to
prop and insert steel beams, but sometimes difficult to be sympathetic at the same time. The
correct balance should always be carefully considered.
Structural Issues and Timber
If you work in conservation you can’t get away
from the structural issues that surround historic
sites, this became more evident when we were
commissioned to repair the Black Barn at Tow
House Northumberland.
The Black Barn as per the images abuve is the
last known example of an original heather
thatched roof in England and had only survived
due to corrugated iron sheeting that had been
put in place in the 1920’s to protect the roof.
The building was archaeologically sensitive
and a grade two star on account of its extreme
rarity of the original heather thatch. This was
a big challenge to us, not only were we dealing
with a rare building in need of great attention
to detail but we also had to weigh up the huge
structural tasks that lay ahead. The roof was
propped internally by scaffold and acrow
props. A structural engineer was employed to
work out the calculations and the support
required to carry out the task. Most of the roof
structure especially to the west slope was badly
decayed due to high winds and driving rain.
This in turn contributed to decay within the
cruck frame structure; most of the rafters were
made from rough hewn cleft oak and were
ready to collapse.
images showing the restoration of Black Barn
34 35

The main cruck trusses showed signs of
extensive rot and were pushing out the
masonry walls. After the crucks were
supported internally the masonry walls
were dismantled and the ends of the crucks
exposed. The rotted ends were treated and
stainless steel bars were resin bonded into
the ends and sides of the existing crucks as
shown in the image to the left.
Most of the existing thatch to the west of the roof slope had to be removed to expose the rotted
scantlings (rafters). Cleft green oak was sourced nearby for the replacement scantlings and were
split on site and laid into position with a wooden rough cut oak peg secured at the top over the
purlin.
Once the ends of the crucks were repaired, the walls were rebuilt with the crucks supported
on a concrete pad stone cast into the hearting of the wall as per the image to the right.
This opportunity to work on this kind of structure was to say the least fascinating, the opportunity
to work with green oak in traditional carpentry, and using an axe for shaping and pegging the
rafters over the purlins. Timber normally is not my forte and in the past I have worked with
masonry projects only until now.
The Black Barn could not have been the success it is without
the lessons taught to me on the Conservation of timbers course
at West Dean College, I managed this project from the site and
was involved in all discussion and final decisions.
36 37

Conclusion
There are many that have had the knowledge in the past to build these prestigious and fantastic
monuments. And there are some that have since learnt the skills from the past to consolidate
them. However unless we continue to train individuals and convert masons and others into
conservation minded people to ensure our standards are kept high, we run the risk of losing our
heritage.
My aim is to carry on and strive to be the best I can in an industry that has in many cases lost
its way. I want to pass my knowledge on to the building, and try to preserve our past so we can
maintain the future of our beautiful heritage.
During my time at West Dean College and my current role as a Conservation Mason I have
made great strides and gone on to manage my own conservation company employing twelve
members of staff. As part of a larger team my company Team Force Restoration Ltd has acted
as the principal contractor on many historic projects.
As a direct result of my training at West Dean and my journey over the last five years we have
as part of a wider team successfully removed from the Heritage at Risk register two buildings.
The Black Barn, Burncliffe, Tow House Northumberland and The Monastic Cell and Medieval
Tower Coquet Island Northumberland. But don’t take my word for this read the words of English
Heritage (10-11).
So can one man
really make a
difference?
4 Over my five years at West Dean College I have learnt and relearnt many lessons. It has given
me the insight to see my past mistakes and made me prepared for future challenges. It has given
me the additional tools that were missing from my tool box and not only progressed my existing
career, but expanded it into new areas too.
From past interventions and lessons learnt, and the lessons learnt from West Dean College my
journey is up to date. I conclude this journal by asking myself again,
To quote Ray from a recent publication.
"There is still a serious shortage of skilled workers who possess knowledge of
the traditional techniques needed to keep the North East's heritage safe” (9)
38 39

“Well I for one believe
that one man can”.
Image of Brendan working on the Marbel floor at Seaton Develal hall40 41

5. Appendices/Case studies
42 43

A mile oﬀ the exposed Northumberland coast is
Coquet Island, a 16-acre bird sanctuary and SSSI with
no public access except from the vantage of a circling
boat or from stories and artists.
Populated by breading birds, including 90% of the UK population of the protected Roseate
Tern, its natural significance overlays an historical legacy of isolated occupation-a Christian
retreat from the land and light for those at sea.
Monastic Cell and Medieval tower,
Coquet Island, Northumberland
A monastic cell already existed there in the
7th century. St. Henry of Coquet (d.1127)
lived there as a hermit monk, after which
there was a Benedictine presence from the
12th century to the dissolution of the
monasteries; the Dukes of Northumberland
have owned the island since 1753.
The Scottish wars prompted the building of
a lookout tower which in 1841 was adapted
into a lighthouse.The first lighthouse keeper
wasWilliam Darling, brother of heroine Grace
Darling; it is still operated today by Trinity
House.
Isolation oﬀers safe sanctuary for the birds
but it has caused problems for the building
on the Heritage at risk register. In 2008 NECT,
supported by English Heritage, undertook a
conservation assessment to determine what
remedial work was required on a range of
venerable structures across the region to
safeguard their future.Though consolidation
of masonry was a theme common to most,
the condition of the buildings on Coquet
Island and extreme exposure made them an
urgent priority for a comprehensive solution.

NECT, as broker and project manager, acted
for all parties under one funding and works
contract agreement for extensive re-pointing
of the starved masonry, comprehensive
overhaul of external joinery and rain water
goods, but also upgrading the 19th century
lighthouse keeper’s cottage as essential
accommodation for the RSPB wardens.
Masonry and joints showing severe erosion. In many areas the mortar was completely washed out, rebuilding and
consolidation within the core of the wall was carried out.
Loose eroded stones were pinned back into position with 6mm stainless steel rods. The photographs above show stones
that have experienced wind erosion and accelerated drying, and salt crystallization, this form of stone decay is known as
Alveoles and is mainly seen on coastal areas or areas of wind turbulence.
Despite the surreal location, works on the island required the
arrangement and consent from a range of authorities (Northumberland
Estates, Trinity House, RSPB, Northumberland County Council, English
Heritage, Natural England), an archaeological investigation (Peter
Ryder), ecological survey (TNEI) and a partnership funding package
before considering contractual preparations and practicalities of
undertaking work on a site restricted by fickle weather and precarious
access.

Working to a schedule of work by design team Spence and Dower,
Patrick Parsons and Thornton Firkin, and within tight CDM constraints
defined by CK21, Team Force’s adeptness of logistical planning would
have frightened off many other contractors. Examples of constraints
included; working to tide timetables; load capacity of boats for
workmen, materials and tools; availability of fresh water; being
banished during the nesting season; re-scheduling at short notice when
the weather turned.
Risk and method strategy was
carried out naturally as you had
to think on your feet, and was
constantly monitored,
sometimes you don’t plan for
surprise; rough seas out of
nowhere were a constant danger
boarding and unloading the boat
of the materials and scaffolding
that we needed for the project.
On the island we put up with
high winds and we constantly
had to check scaffolding and
even strap down boards that had
become loose due to the high
winds.
There was also a risk of being
stuck on the island and this did
happen on one or two occasions,
to get around this we had to take
extra provisions at the start
including heating, food, and fresh
water. As a whole we learnt to
think about the risks associated
with construction on a different
level, due to the severity and
hazards of this project, this also
had a great impact on the team
both on the island and for the
staff onshore, constant liaising
and planning was the key to
success.
Grouting core work, pinning of existing stones, extensive deep mortar tamping, and repointing were required to consolidate
and strengthen the masonry walls. Mortars and grouts were carefully gauged to ensure the mortars could withstand the
very unpredictable weather conditions on this island.
The need for protecting the mortar whilst the initial set took place was very important, heavy Hessian sacking with polythene
was laid over the masonry walls for a minimum of two weeks.

Though management of a contract in these circumstances is in itself an
achievement, the quality of the conservation work has in no way been
compromised, nor has the philosophical justification for the decisions
about techniques or specification. It has been an exemplary exercise in its
preparation and co-operation of stakeholders, showing that heritage at risk can
be safeguarded and sustainable in even these conditions, but especially in
contract management and conservation expertise, despite everything thrown
in the way (sometimes literally).
All stone was sourced from the Northumberland stone quarry, the new stone replacements to the lighthouse and cottage
was cut on site and tooled to match existing.
Mortars for repointing and stone repair were NHL 3.5 lime and styford sharp sand. Styford sand was chosen for it well graded
particles this meant that no softer sands were used, in most coastal locations soft sand can’t withstand the severe conditions
that are thrown at it.
The existing roofing slates to the cottage roof were coated with bitumen; we did salvage some slate material and brought
in reclaimed Welsh slate to match both in color and size.
During this contract we employed our two bursary operatives James and Barry enduring all, the project provided vital training
in stone fixing, mortar repair, pinning, deep tamping, and grouting. AS part of the contract we also obtained additional
training funds from English Heritage as a percentage of the work sum, this funding has helped James and Barry on a banker
masonry course in Northamptonshire, known as The Orton Trust.

Team force
The Black Barn, Burncliﬀe, Tow House

The project was started in December
2012 with the erection of scaﬀolding and
a temporary roof which was retained
until December 2013 so that all the work
was done under cover to completion.The
project was very substantially grant-
aided by English Heritage supported by
Northumberland County Council and
included provision for Heritage Skills
Training through H S I run by North of
England Civic Trust.
The challenge:
an archaeologically sensitive site Listed
Grade II* on account of its extreme rarity
with original heather. The building had
been on the Heritage at Risk Register
compiled by English Heritage, its
condition noted as‘Very Bad’. A change of
ownership in 2008 gave fresh impetus to
finding a way forward to develop
appropriate techniques of repair
informed by an archaeological
investigation of the surviving fabric.
Heather thatching was widely used in the English
uplands before the mid-19th centurybut by the end of the
century in the face of the wide distribution of Welsh slate by
railway to every part of Britain the skills of thatching were largely
lost and very little heather thatching is now attempted.
his last known example of an original heather thatched roof in
England had survived protected by corrugated iron sheeting fixed in
the 1920’s.This had been removed in 1990 when some minor repairs had
been attempted, but prolonged exposure since then had left most of the
South-West slope either torn oﬀ by winds or degenerated into peaty
compost. This had also contributed to decay and loss of timber in the
cruck frame, with most of the rafters (rough cleft oak) in that slope ready
to collapse. On the North-East more sheltered side much of the base coat
of original heather thatching had survived better and most of the rafters
were sound. Temporary props and bracing were introduced inside the
building to make the structure safe.
Project Description
T

Most of the existing waist coat to the rear had
to be removed to expose the rotted scantling
rafters, after they were removed we installed
new oak scantlings

nglish Heritage have been very keen to encourage a revival of interest
in historic building skills and the unexpected opportunity to study this
unique 300 year old thatch gave many exciting clues to lost details of the
craft.The thatching sub-contract was to include experiment in recovered
techniques to ensure more durable performance.
Finding any thatcher with experience of heather in England was diﬃcult
and the trade is very fragmented with no formal accreditation scheme.
E

asonry consolidation and timber repairs were carried out and an
opportunity to work with green oak in traditional carpentry
workmanship, using axe and augur for shaping and pegging rafters over
the purlins.
The main cruck trusses were rotted and were pushing the masonry
walls out.The crucks were supported and the masonry walling had
to be dismantled to expose the rotted ends of the crucks.The ends
of the crucks were treated and resin bonded. Stainless steel bars
were resin bonded into the ends and sides of the existing crucks.
Once the ends of the crucks were repaired the walls were
rebuilt and the ends of the crucks were supported on
concrete pad stones cast into the masonry walls.
This photo shows the end of the cruck built
The only metal introduced was the use of new steel bolts to strengthen
joints between the cruck blades and the collars. Opening up the feet of
the cruck blades hidden in the walls revealed extensive rot. This was
carefully cut out in-situ and extensions were built up in epoxy resin
reinforced with stainless steel rods.
M

Then the essence of the vernacular
tradition lies in the application of
local skills working on locally
available materials. In an historical
context transport would have
represented a greater problem over
long distances than it does today so
stone and timber would reflect local
sourcing as a preference. As the
geology of much of
Northumberland provides easy
access to sandstone for building
and limestone for burning with coal
(also locally available) one can see a
self-suﬃcient rural economy behind
the original construction of the
barn.
It was expected in this project that
the archaeological study would also
yield information about the organic
materials and possibly even identify
their sourcing. Materials for the
thatching are by their nature
sustainably managed, most of it
locally sourced from sites in
Northumberland: all the heather,
hazel sways and liggers were winter
cut. Spars, also hazel, twisted into
staple-form are commercially
produced in Somerset from
sustainable hazel coppicing. Clay,
peat and sphagnum moss were all
available within a few miles of the
barn. So too was the timber for the
replacement rafters, cleft green oak
from the woods around Slaley in
South Northumberland supplied by
Hexhamshire Hardwoods.
Working all these natural materials required little more
than human strength and skill applied to shape, place
and fix by hand. So the embodied energy was very low
indeed and the carbon footprint nil, except in short-run
transport from moor to site.
hile clearly a simple unheated historic barn used
as domestic outhouse storage cannot be
presented in terms of its ‘in-use’ energy performance
there is much that can be said about sustainability in
its favour.
First of course is the buildings age, in use for 300 years on the same site,
the only substantial modification being the removal of two bays from the
North end to allow the construction of cottages in the 1890’s.
Accommodation for that was made by building a new brick gable at that
end to pick up the timber roof structure.
W

here is another issue important to the wider community which is
the cultural transmission of skills. English Heritage was keen to
promote, through the archaeological investigation of the thatch, a wider
interest in heather thatching. The practice arranged, with the North of
England Civic Trust, to run Heritage Skills Training Days for Masonry,
Carpentry and Heather Thatching. The barn will be accessible in the
future for further education and training and the Consultant Team is
currently writing reports and articles for publication in peer-review
professional journals as part of the Archaeological Research Project,
separately funded by English Heritage under their Regional Capacity
Building Grant Scheme.
Thatching works in progress, the thatch was built up in layers. Completed building with its thick coating of thatch.
T

List of Masterclass
The Historic Interior, Commissioning and Managing Conservation Research, 8-
10 February 2010.
The course was lead by Helen Hughes, with tutors Crick-Smith and Michael Crick-Smith. This
was a compulsory course for the development of the PDD Building Conservation Master classes
and probably one that I would not have chosen to be honest as I does not represent my current
working practices. I think I can say that as I am a stone mason and not particularly interested in
interiors, but having said that how could I not be interested in interiors!! In this course I fully
appreciated the gilding techniques and found the paint layer analyzing techniques very
interesting too. The course was very good but a bit hard for me to grasp that’s all. That said you
only have to look inside the West Dean house to see that interiors really do matter and are just
as important as the exterior fabric.
Mortars for Repair and Conservation 5-8 November 2012.
This course was lead by Colin Burns, with tutors Catherine Woolfitt, Graham Abrey and Gerry
Williams. This course was essential to me as a conservation mason, and to be successful in
conservation you need to learn how to mix mortar and recognize that all mortars including their
binders and aggregates are not all the same. Mortars form the basis for nearly all masonry work
and there is so much to take on board in such a short time. This was one of the best courses I
have been on and would definitely recommend it to others. I am going to say no more about this
course for now because I hope it will become evident later in my journal that I have definitely
applied the skills learnt on the mortars course and put it to good use.
Conservation and Repair of Brick and Flint Masonry, 22-25 April 2013.
The course was lead by Graham Abrey with Colin Burns, Peter Minter, Emma Simpson, and
Duncan Williams. Brick is not normally a material that I have used on past conservation projects,
and flint is definitely a new one to me. Living and practicing my trade in Northumberland I
can’t ever remember seeing any flint built buildings so it was very educational to see how flint
was put to good use in the south of England to create these stunning buildings. Look no further
than West Dean College and you will see probably one of the best examples of flint masonry. I
can’t imagine how long this task would have taken, the discipline and patience of the masons
here would have been key to the success of this type of building. There were also some fantastic
demonstrations by Emma Simpsonon brick rubbing and building arched work over formers, the
mortar joints between the brick Vousuars were so tight and the finished work looked stunning.
As I write this we have just been awarded a contract involving brick building and pointing in a
walled garden at Auckland Castle and I am now definitely prepared after attending this course.
Masonry Cleaning, 24-27 June 2013.
The course was lead by David Odgers with Brian Klelund, Sean Brennan, Richard Cook, and
Jamie Fairchild. Before attending this course I had never cleaned any building, well I suppose
soft brushing, sometimes with water can be included as cleaning so maybe I have touched on
the subject. To be honest I was afraid of this area of conservation as I did not have the knowledge
to see it through and there are enough horror stories going around to frighten you off tackling
this type of work. This course was always going to be a favorite for me and my eyes and ears
could not afford to go into switch off mode during the lectures. As the course progressed I
realized that there was more to this than I thought, cleaning was definitely an art and not to be
misunderstood or disregarded as a conservation method. At times I left the lectures with more
questions than answers so I had to make it my business to constantly be involved in the
44 45

discussions. I would not call myself a masonry cleaning contractor as I still feel that there is
more to learn however the course gave me the confidence to start carrying out basic cleaning.
After the course I got in contact with Jamie Fairchild and I set up an account with his company
Restorative Techniques, we now carry out cleaning works under his helpful guidance and use
their full range of products, and to date we have successfully cleaned three buildings. This would
not have been possible before I attended this course.
Conservation and Repair of Stone Masonry, 30th Sept-3rd Oct, 2013.
The course was lead by Graham Abrey with Colin Burns and Duncan Williams, once again we
are back to my area of expertise. If you are a mason and you work on historic properties you
need to come on this course so that you can develop your skills and maybe in time you can call
yourself a conservation mason and not just a stone mason, (there is a difference). I could say at
this stage that I had a bit of experience working on historic sites and I was in fact an experienced
mason. But the courses always seem to have a knack of reminding you that there is much to
learn on this journey and you realize this every time the tutors open their mouths and speak of
their knowledge. How and why do stones decay, cutting out stone and repairing with mortar,
cutting stones out and repairing with stone, this is this all relevant in conservation and essential
if you want to become a successful conservation mason. (Yes I do)
Conservation and Repair of Timber, 14-17 October 2013.
The course was lead by Joe Thompson with Peter McCurdy and guest lecturer Brian Ridout. Ill
be perfectly honest here and say that if this course had not been a compulsory one, or I had the
option of replacing this course with another one I would have done so. The reason for this is
that I consider myself as a mason and not a carpenter; therefore the timber course would probably
not serve me much use on my journey into conservation!! These words now come back to haunt
me, why and how I came to think this seems ridiculous now, and it will become evident soon
when you peruse further into my journey in conservation. This may have been the most important
course that I have carried out at West Dean so far and has helped with the conservation repair
techniques that have gained national recognition for one of the most successful repairs of an
original heather thatched Cruck Barn in Northumberland, the barn has also been removed off
the Heritage at Risk Register.
Conservation of Architectural Detail and Surfaces, 31March-3rd April, 2014.
This course was lead by David Odgers with Colin Burns, Ben Wild, and Duncan Williams. This
was again my area of interest and expertise, the course content was great, mortars again were
mentioned but with additional information essential to my development. What Graham Abrey
left out in previous courses David filled in for in this one, and as previously stated it is impossible
to cover all of conservation in one course. I did here hear on occasions from West Dean diploma
students that there was too much repeat on mortars on the courses however I am not sure why
they feel that this is the case. Yes there is a repeat of mortars on a lot of the courses so it is
inevitable that some of the demonstrations are repeated but how can you learn all about mortars
in one course. As said earlier mortars are the basis of almost all masonry conservation and are
essential in the consolidation and repair of our historic buildings, there are many mortars to
consider and different strengths of binders. This element of the conservation diploma should be
repeated and repeated again and again as far as I am concerned, and should be permanently
etched in ones brain to ensure that they are mixed and applied successfully.
46 47

Specifying Conservation Works, 9-12 February 2015.
This course was lead by Malcolm Starr with Rhys Brookes, John Lloyd, and Adrian Stenning.
This course studied initial surveys, project planning, and correct specification. As a conservation
mason I don’t get to specify my own repair works and I often wondered why specifications were
so vague and in some cases incorrect. Coming into this industry I thought that architects,
surveyors, and the like would all know what to write when specifying the works on historic
buildings. The fact is some don’t and this can be just as dangerous as the builder that does not
know what lime mortar is, as he applies his bucket of cement. I am also growing increasingly
disappointed when so called conservation architects class me as a builder, and this is their first
mistake. Not knowing the difference from a builder and a conservation mason will lead to a
disaster in conservation applications. This course was not essential to me but gave me the
opportunity to understand why specifications are not always correct. This course will teach
contract administrators the knowledge that they need to write a site specific conservation
specification to ensure that the conservation companies carrying out the practical tasks on site
are fully aware of what they need to do.
Conservation and Repair of Plasters and Renders, 30 March-2nd April, 2015.
The course was lead by Graham Abrey with Colin Burns, Richard Childs, Jeff Orton, and
Duncan Williams. This is my tenth and final course for the completion of the PDD Building
Cons; Diploma. Although I had good tool skills going into this course Plastering was not a
strong point for me. I have always been fascinated in ceiling moldings in historic properties
and was equally fascinated in how all the ceiling moldings were created, especially during
the demonstrations by the tutor Richard Childs. The demonstration on mortars was again
repeated in part and this time round I could almost predict the words coming from Colin Burns
mouth, and was this a good thing?? Yes it was a great thing because now for the first time I
actually understood and knew about mortars and maybe now I can call myself a conservation
mason. I felt for once very capable, Capable of moving on and upward into a conservation
world that would hopefully mould and shape me for the rest of my working life on historic
buildings.
48 49

References
1. English Heritage. “Our History”. Available: http://www.english-heritage.org.uk/about-
us/our-history/. Last accessed 5th February 2015.
2. Stockdale, R. (2015) Discussion on Hadrian's Wall [Telephone Conversation]. 15th
January 2015 12:42. Technical Manager English Heritage
3. Stockdale, R. (2015) Second Discussion on Hadrian's Wall [Telephone Conversation].
21th January 2015 15:08. Technical Manager English Heritage
4. Stockdale, R. (2015) Discussion on Alveolar Erosion [Telephone Conversation]. 5th
February 2015 09:05. Technical Manager English Heritage
5. Stockdale, R. (2015) Discussion on Scotch Pointing [Telephone Conversation]. 7th
February 2015 10:00. Technical Manager English Heritage
6. Starr, M. (2015) Specifying Conservation Works Lecture. February 2015. West Dean
College
7. Allington-Jones, L 2013 “The Phoenix: The Role of Conservation Ethics in the
Development of St Pancras Railway Station (London, UK)” in The Journal of
Conservation and Museum Studies, 11(1): 1, pp. 1-21, DOI: http://dx.doi.
org/10.5334/jcms.1021205
8. Historic Scotland. November 2005 “Masonry Decay: Dealing with Erosion of
Sandstone”, Technical Conservation Research and Education Group. Available:
http://www.historic-scotland.gov.uk/informguide-masonry.pdf. Last accessed 5th
February 2015
9. Harris, A (2008) "Get your hands on Heritage Skills", Issue 3, Heritage Skills
Initiative, Available at: http://www.nect.org.uk/hsi. Last Accessed: 10th March 2015
10. English Heritage “Heritage At Risk” Available: http://www.team-
force.co.uk/Content/Documents/blackbarn-register.jpg. Last accessed 5th February 2015
11. English Heritage “Monastic Cell and Medieval Towner on Cosquet Island, Hauxley, Northumberland”
Available: http://www.team-force.co.uk/Content/Documents/hertiage.jpg. Last accessed 5th February
2015
50 51

Bibliography
• Building with lime, A practical Introduction. Stafford Holmes and Michael
Wingate. Revised Edition 2002.
• Stone Conservation, Principles and Practice. Edited by Alison Henry.
• Stone Buildings, Conservation, Repair, Building. Patrick McAfee.
• Cleaning Techniques in Conservation Practice. Edited by Kyle C. Normandin,
Deborah Slaton, Consultant Norman R. Weiss.
Acknowledgements
Firstly I want to thank my grandfather for taking the time and effort to take me to see our
heritage and for planting a seed firmly in my mind. Next I want to thank Ray Stockdale for
believing in me in the early days pre West Dean when my carrier was at a cross road, and
introducing me to West Dean.
Last but not least, I want to thank West Dean College, for looking after me and feeding me
with their famous meals, but not for making me fat. West Dean also gave me the best
conservation education and has made me more confident when facing on site decisions.
I want to especially thank Liz Campbell who is in the front line of all correspondence, and the
following tutors and consultants. Without the dedication of the tutors the course’s would not
exist.
David Odgers, Graham Abrey, Colin Burns, Duncan Williams, Gerry Williams, Brian
Klelund, Catherine Woolfitt, Joe Thompson, Peter McCurdy, Peter Minter, Malcolm Starr,
Helen Hughes, Kate Clark, Patrick Baty, Rhys Brookes, John Lloyd, Adrian Stenning,
Richard Childs, Jeff Orton, Ian Hume, Terry Girdler, Arthur McCallum, Emma Simpson, Ben
Wild, Sean Brennan, Richard Cook, Jamie Fairchild.
52 53

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