1. FLOORING AND SCREEDING
The drying game
The amount of screed that can be installed in a set period is only half the story. If you include
drying times you may well find that what you think is fast track is anything but.
Adrian JG Marsh finds out how pressure on site is damaging floor screeding.
“How often have I heard a site
Isocrete
manager say we’ve had nothing
on this floor; only for him to turn
around and see a machine
driving towards us on the newly
screeded floor!” says Dave
Taylor of screeding contractors
Roseville Plastering.
The ability to lay large areas
of floor screed in a short time
may initially be considered ‘fast-
track’. However some clients
seem unaware of the pitfalls of
using a floor before it’s ready
and the impact on the resultant
integrity of floors, especially with
screed laid over insulation or
under floor heating.
Dave Taylor explains: “Main
contractors and developers
are under so much pressure
to get jobs finished and want
to work on the floor as quickly that insulation. Screeds and the company’s technical
Roseville Plastering
as possible.” insulation react in different manager, says: “FlexiDry fast
“What we try and do is to ways. All screeds, no matter drying floor screed is 20 to
advise them on the choice of how well laid or strong, are 30 per cent more efficient as
products that offer various at risk of cracking. British a thermal conductor than an
drying times and options to Standards recognise that anhydrite screed.
improve the programme.” screeds tend to crack “A standard screed laid at
Spencer Warner of randomly as they dry and 75mm depth will generally take
contractors CSC Screeding shrink. at least 110 days to dry before
agrees: “Perhaps the biggest Dave Taylor says this can you can lay your final floor
problem in the market place for occur because areas are not finishes. With our new F0 fast
screeders is plant being driven sealed properly to allow curing: drying floor screed you can lay
over screeded floors before “Rooms need to be a sealed your flooring finishes after just
they have cured properly. environment and then opened three days.”
“You often see scissor up to allow the floor to breath.” Floors have joined
lifts running over floors before Peter Dolby, commercial mechanical and electrical
they have reached their director at Isocrete, adds: services as another excuse
final strength 28 days after “The risk of cracking is highest for the delay on a whole range
installation. If they’ve not set for floating and unbonded of projects. But more often
properly they won’t take the screeds; they are usually than not it’s the pressure of
loads of modern plant and the reinforced to help control crack time and perhaps a lack of
floor gets damaged. width and spacing.” understanding that sees other
“Concrete technology Fast-drying screed trades being asked to work on
has changed considerably such as Ardex, FlexiDry, screeded floors before they are
during recent years and by Isocrete’s K-screed, and ready and so damaging them.
using additives the speed of Tarmac’s Truscreed, use When specifying a flooring
hardening and setting can be super-plasticisers to reduce screed, it is important that
controlled. What once took a the amount of water needed clients take all the relevant
month can now be achieved to make the screed mixture factors into account during
in hours. pliable; this in turn makes for the decision-making process.
“Being able to offer a main a fast drying time as there is a It’s important that they assess
contractor a shorter installation higher cement to water ratio. what ‘fast-track’ means and
period and hand the area over The drying times for these are the effect it will have on a
early is a big bonus.” generally around 3mm per day. programme but what’s clear is
The load capacity of any FlexiDry is the most that the potential implications of
screed laid on insulation is recent entrant of these into using new screed technology
dictated by the strength of the market. Simon Bateman, on programme is considerable.
14 Advertising 01926 420660

2. FLOORING AND SCREEDING
Flexidry F2 fast drying screed is being
Fast drying in
installed at Uxbridge College in Middlesex
Uxbridge, Middlesex
FlexiDry’s F2 (14-day dry time) fast drying floor screed is
being installed on an underfloor heating system at Uxbridge
College’s new £6 million sports and leisure development
which will include indoor and outdoor facilities for a wide
range of sports and activities.
Kier Group is main contractor for the new sports hall and
chose FlexiDry for its ability to change the screed dry time on
site with just one product, but also thanks to its sustainable
qualities including reduced thickness, less waste and
increased thermal conductivity.
Originally a 21-day dry time option was chosen for the
project but as timescales came under pressure to have the
final floor finishes laid, Kier changed to use the 14-day dry
time option. This was able to be done without any change to
the specification.
The new sports hall caters for a wide range of activities
including five-a-side football, cricket, basketball, netball and
volleyball, and there’s a full-size electronic scoreboard. The
hall will be 50 per cent taller and 50 per cent bigger than the
original building.
The new hall will also be used for Uxbridge College’s
Sports Academies in football, basketball and cricket,
enabling the college to expand its range of sport coaching
qualifications.
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