5 Broadgate British Land Hot Melt Solution - Ben Stuart, Make Architects

8 STEPS TO THE PERFECT ROOF
THE BUILDING CENTRE, STORE STREET, WC1E 7BT
IKO PermaTEC
5 BROADGATE
BEN STUART
22ND OCTOBER 2014

8StepstotheperfectroofPage2
Introduction
My Name is Ben Stuart and I work for Make Architects
Ben Stuart
+ Joined Aug 2010
+ Qualified in Dec 2012

5 Broadgate
+ UBS Bank London HQ
+ 7000 Staff over 13 Floors
+ 750,000 sq Ft office

Onsite - Completion 2015
+ I began Post Stage C
+ Roll has increased to run
terraces & Ground Floor
interfaces

To give you some background on 5 Broadgate
This project is part of the Broadgate development in the city of London as part of the
liverpool street station
Broadgate - Site

The Client

‘The most cost effective, sustainable solution
that will provide a robust waterproofing
system to last the life-span of the project’

Sustainability
BREEAM Excellent

British Land Sustainability Brief For Developments

Elements Material Recycled content
(%)
Total volume (m3
) Unit cost (£/m3
)
material only
1. Liquid applied membrane
2. Drainage Mat
3. Thermal Insulation
4. Filter sheet
5. Pedastals
6. Concrete Paving Slab
7. Stone
8. Planter container
9. Root barrier
10. Cemetitious board
Tender Sustainability Submittal sheet
Package 3600 Sustainability submittal sheet
1
Architect: Make Architects
Project name: 5 Broadgate
Document number: Make-SUST-3600
Reason for issue: Tender
Revision: 00
Contractor: [Add name]
The purpose of the sheet is to ensure that the contractors have taken account of the sustainability criteria set out in the tender
documentation and that it is achievable within their proposals at tender stage. This is intended as a summary sheet only and
the contractors should refer to the specification for further information.
REF QUESTION TARGET
(minimum requirements)
RESPONSE
(Confirm targets are achievable)
1.0 LIFE CYCLE ASSESSMENTS
1.1 The contractor shall provide a Green
guide assessment of the proposed
construction certified through the BRE.
(BREEAM Credit Ref: MAT 1 & 6)
Insulated metal cladding - A+
Thermal insulation - A+
Waterproofing system - D
2.0 RECYCLED CONTENT
2.1 The contractor shall provide the
recycled content and (area/ volume)
for each component based on their
selected manufacturers (WRAP). The
minimum recycled values are required
for the following items:
Insulated metal cladding - 15%
Insulation - 30%
3.0 ENVIRONMENTAL
ACCREDITATION
3.1 The components of all systems shall
achieve BS EN ISO 14001 for
manufacture (* with BS EN ISO 14001
for manufacture and extraction for
thermal insulation).
Insulated metal cladding - ISO 14001
Insulation - ISO 14001*
3.2 The contractor shall provide
information regarding responsible
sourcing of all external stone
No natural weathered limestone is to
be used in buildings or landscaping
4.0 EMISSIONS
4.1 The contractor shall provide evidence
that their products, its installation and
maintenance are free from toxins (i.e.
VOC’s, HCFC’s, CFC’s etc).
Insulation to be free from HFC, CFC
and HCFC’s. A GWP of less than 5
and ODP of zero.
(BREEAM Credit Ref: HEA 9 & MAT
6)
REF QUESTION TARGET
RESPONSE
5.0 Replacement intervals
5.1 The design life of the building shall be
as BS ISO 15686: Part 1, 60 years and
with BS 7543 category 2 maintenance
level. The components shall have
predicted service life of not less than
the following:
Framing sections - 30 years
Fixings systems - 30 years
Cladding panels - 20 years
External gaskets - 20 years
Silicone sealants - 20 years
Internal concealed gaskets - 30 years
Roof coverings - 30 years
6.0 EMBODIED CARBON ASSESSMENT
6.1 The contractor shall provide an
embodied carbon assessment of the
cladding elements in Kg/ CO2/m2.
No specific target set

1
REF QUESTION TARGET
RESPONSE
1.0 LIFE CYCLE ASSESSMENTS
1.1 The contractor shall provide a Green
guide assessment of the proposed
construction certified through the BRE.
Insulated metal cladding - A+
Thermal insulation - A+
Waterproofing system - D
Insulation - 30%
3.0 ENVIRONMENTAL
ACCREDITATION
4.0 EMISSIONS
and ODP of zero.
2.0 Recycled content
Roofing Installations ‐ Recycled Content BRIGGS AMASCO TP3600
Element / Description Material Recycled content of
Material (%)
Volume of material
installed (m3)
RC % x Total Volume
Liquid applied membrane PermaTEC 43% 71.54 30.76
Drainage mat Drainage mat 100% 99.60 99.60
Thermal insulation Dow 20% 1,800.60 360.12
Filter sheet Min ‐ K 0% 0.00 0.00
Pedestals To be confirmed 0% 0.00 0.00
Concrete paving slab As specified 0% 51.21 0.00
Stone As specified 0% 49.66 0.00
Planter container To be confirmed 0% 0.00 0.00
Root barrier PermaTEC 43% 13.72 5.90
Cementatious board To be confirmed 0% 0.00 0.00
Totals 2,086.33 496.38
Total Recycled Content by Volume of material 24%
Note: Total Volume of material should be the total volume of materials to be installed in the permanent structure i.e. recycled and un‐recycled
Roof element target 5%
Element target met, but recycled
content for insulation only 20%

ISO 14001 - For installation contractor ISO 14001 - For manufacture ISO 14001 - For extraction
1
Insulation - 30%
3.0 ENVIRONMENTAL
ACCREDITATION
4.0 EMISSIONS
and ODP of zero.
3.0 Environmental Accreditation Mat 5 Insulation
The following materials of the roof element are required to
be responsibly sourced (Iso 14001). Plastics, rubbers,
bituminous materials and concrete/ pre-cast/ building stone.
Mat 6
ISO-14001 for extraction and manufacture
Also see item 1

From BBA certificate for Permatec
hot-applied monolithic roofing and
waterpoofing system
5.0 Replacement Intervals
2
(BREEAM Credit Ref: HEA 9 & MAT
6)
REF QUESTION TARGET
RESPONSE
5.0 Replacement intervals
5.1 The design life of the building shall be
as BS ISO 15686: Part 1, 60 years and
with BS 7543 category 2 maintenance
level. The components shall have
predicted service life of not less than
the following:
Framing sections - 30 years
Fixings systems - 30 years
Cladding panels - 20 years
External gaskets - 20 years
Silicone sealants - 20 years
Internal concealed gaskets - 30 years
Roof coverings - 30 years
6.0 EMBODIED CARBON ASSESSMENT
6.1 The contractor shall provide an
embodied carbon assessment of the
cladding elements in Kg/ CO2/m2.
No specific target set
7.0 Thermal performance
7.1 The contractor shall provide a thermal
assessment of their proposals to
demonstrate compliance with the
following maximum thermal
transmittance (U-value):
External Wall - 0.27W/m
2
K
Roof - 0.20W/m
2
K

Waterproofing Systems
Design Stage

Explored multiple waterproofing systems at the beginning of the project
1. Warm Roof
2. Inverted Roof - Cold applied liquid plastics
3. Inverted Roof - PermaTEC Hot Melt
5 Broadgate is a concrete decked, steel framed
construction with a flat roof:

1. Warm Roof
This is not really suitable for
plant area
Heavy plant requires a
concrete overslab
If waterproofing is
penetrated it is very difficult
to find out where the leak
has occurred.
Most suitable for roofs with
falls.
Insulation beneath doesn’t
provide a structural base.

2. Cold applied liquid plastics inverted roof
Safe & Easy to install
Can cover very intricate details
Can be installed on a damp slab
Expensive compared to hot melt
Life span is only 20 years

3. PermaTEC Hot Melt Inverted Roof
Cost effective
Fast construction time
Lasts the life span of the project
Suitable for flat roofs
Cannot be installed on wet or
damp concrete
Difficult to seal intricate details

Beginning of the project British Land were very keen on an Hot melt inverted roof system:
This was a system they were familiar with and offered clear advantages for 5 Broadgate:
- Cost effective (25% cheaper than Liquid plastics)
- Hot melt is simple and fast to install
- Rapid setting (allows fast turnaround of areas to other trades)
- 6mm completed membrane thickness is very tough and resistant to impact
- Hot melt remains in a semi-liquid state and is able to self heal
- Proven material on other British land projects
- Was even used on original Broadgate scheme back in 1984!

Beginning of the Project I was handed a document:

IKO PermaTEC Hot Melt
Inverted Roof explained

Typical PermaTEC Hot Melt Inverted Roof: In
8. Ballast / Concrete overslab
7. Drainage Mat
6. Insulation
5. Protection Felt
4. 2nd 3mm Layer of hot melt
3. Reinforcement layer
2. 1st 3mm Layer of hot melt
1. Primed Concrete

1. Primed Concrete
Concrete Cleared of
Latents
Peal test to ensure
waterproofing will bond
Primer Applied

2 & 3. 1st 3mm Layer of hot melt & Reinforcement Layer
Hot melt is spread to a
depth of 3mm and 1m in
width with a squeegee
PermaFLASH-R (reinforcement
layer) is then embedded into the
hot melt
Ensure minimum 100mm overlap
Once completed 1st layer of
PermaTEC and reinforcement
layer is completed, 2nd coat
can be applied immediately

4 & 5. 2nd 3mm Layer of hot melt & Protection Felt
NOTE:
Major Advantage over Liquid plastics - Each
layer requires 8 hours minimum to harden
2nd 3mm layer of Holt melt
applied
PermaGuard protection applied. Ensuring minimum 100mm
overlap

QA Testing: Prior to installation of finishes
Hot melt
installation is
depth checked
every 25m2 to
ensure required
coverage
Must be done immediately
before the installation of
finishes
Depth Check Electronic leak Testing leak identification Localised Repairs

6,7 & 8. Insulation, drainage Mat & Overslab
6. Insulation then placed on
waterproofing to protect
7. Drainage mat is installed
beneath overslab to aid water
flow and also to ensure winter
freeze thaw with the overslab is
not an issue.
8. Ballast / Pavers installed to
weight down insulation
NOTE:
If drainage mat is installed
beneath insulation this creates
an air gap and will negatively
impact u-value calculations

Penetrations: The magical Pitch Pocket
Pitch pockets used for all
vertical penetrations. Services /
handrails / posts / I beams etc
1. Minimum 50mm galvanised
metal formwork bonded into hot
melt.
2. This is then secured with more
hot melt or mechanically fixed.
3. Filled with PermaTEC hot melt
4. Protection felt then covers
pitch pocket

5 Broadgate
PermaTEC Roofing Details

Current Site Camera Image

Roof Plant Layout

Roof Axo + PV Plant Screen

Lv12, Lower Roof, Upper Roof: Section
Lv12
Lower Roof
Upper Roof

Cladding Bracket
50mm perimeter upstand.
Used to create low level bund
to aid during construction.
This also lifts the water
proofing detail out of standing
water, due to the flat roof and
syphonic drainage
Hose testing required
on final detail

Before After

Cladding bracket flashing
PermaTEC
PermaTEC Pitch Pocket
prior to protection fleece

Generator Support Base
150mm Above Finshes

Inspecting the slab for
latencies and drying the
slab prior to peel test
Sectional completion of
waterproofing, ensuring
minimum 100 overlap

Leak testing, sign-off and repair
done prior to laying of insulation
Insulation laid straight after successful leak
test to ensure protection from other trades

MUST AVOID:
MEWP Wheels can easily tear
the waterproofing
MUST AVOID:
Sharp container edges are also an issue

Structural Column Penetration
50mm concrete penetration upstand.
This acts as a first line of defence and
lifts the water proofing detail out of
standing water, due to the flat roof
and syphonic drainage
on final detail

Initial column penetration 50mm PermaTEC
pitch pocket ontop of 50mm concrete
upstand
Flashing cover installed ontop of column plate
to stop water flowing down the column.

Core cladding - Concrete Upstand
150mm Above Finishes

Roof Service Penetrations
50mm
concrete
upstand

Lower Roof Waterproofing details

With a roof space of over 75,000 sq ft, the
cost and speed of installation are crucial

Weather is also a crucial component.
Hot melt cannot be laid on a wet surface.
tents and temporary bunds were used.

Tricky Details - Unexpected Issues
The dreaded
cross brace
connection

Even though the base detail has a pitch pocket,
water can track between the connection plates

The solution was to use cold applied
liquid plastics around the connection
plate
Cross Bracing Connection - Hybrid Solution
50mm concrete upstand.
This acts as a first line of
defence and lifts the water
proofing detail out of standing
water, due to the flat roof and
syphonic drainage
on final detail

In this case cold applied liquid plastics are cheaper
than a pitch pocket and much simpler to apply in a
tight area.

The trickiest detail - The Mega Truss

Steelwork contractors coordination model.
The waterproofing detail needed to fit beneath the web of
the beam and slab (130mm).
Notice the lack of bolts shown...

Bolts. Lots of Bolts!

The bolts had actually been cast into
the structural slab.
This required a total rethink of this
detail

Nicknamed “the coffin“ on
site
Localised 48 hour flood test
carried out around truss Successful detail
leads to happy
construction team

Conclusions
PermaTEC Roofing
Solutions

- Has provided a cost effective robust solution (25% cheaper that using just cold applied liquids)
- Sustainable solution for 5 Broadgate (Recycled content of PermaTEC is 43%)
- Working with a competent contractor and rigorously sticking to the QA procedure is crucial
- A hybrid detail of hotmelt & liquid plastics on complicated penetrations works very well
- Some key design considerations
- Try and design out the awkward details before you get on site. Ie structural /
services connections
- Ensure all waterproofing finishes 150mm above FFL
- Where possible ensure penetrations are in the vertical plane not horizontal
- Best to keep penetrations inside plant rooms
- Bunch penetrations together (But not too close)
- Construction perimeter upstands very successful detail
Recommendations IKO PermaTEC on 5 Broadgate

- From a designers point of view it needs to be questioned whether we should really be
specificity hot melt, that is a potentially dangerous process on site.
- I think that with Modern Methods of Construction that the days of using waterproofing as a
second pass process are limited. With the development of waterproof concrete and advances in
applied plastics there will be less use for hot melt.
- Finally I think we as architects need to think about how we can standardise these details to stop
us reinventing the wheel each project.
Final Thoughts

www.makearchitects.com
13 Fitzroy Street
LondonW1T4BQ
tel +44 (0)20 7636 5151
fax +44 (0)20 7636 5252
www.makearchitects.com
Copyright Make Limited 2014. No unauthorised
reproduction of any part of this Document is permitted.
Introduction
My Name is Ben Stuart and I work for Make Architects
Ben Stuart

5 Broadgate British Land Hot Melt Solution - Ben Stuart, Make Architects

Recommended

Recommended

More Related Content

Similar to 5 Broadgate British Land Hot Melt Solution - Ben Stuart, Make Architects

Similar to 5 Broadgate British Land Hot Melt Solution - Ben Stuart, Make Architects (20)

More from SIG Design and Technology

More from SIG Design and Technology (20)

Recently uploaded

Recently uploaded (20)

5 Broadgate British Land Hot Melt Solution - Ben Stuart, Make Architects