Why Re-roof? Repair and insulate in one go!

Why Re-roof?
Repair and
insulate in
one go!
Don’t leave it too late to carry out
repairs to your roof – it could save you
thousands of pounds. Take advantage
of modern polyurethane technology
to save your existing roof and avoid
the much higher cost of a re-roof.
You may not be aware that if you are
repairing more than 25% of your existing
roof, the roofing contractor is now legally
obliged to advise you to notify the Local
Authority Building Control Department, to
comply with the new Part L Building
Regulations. Generally the whole roof will
need to be brought up to current thermal
efficiency required under Building
Regulations. This is to comply with the
European Energy Performance of Buildings
Directive, and part of the Government’s
drive towards achieving zero carbon
homes by 2016.
Polyurethane foams can be economically applied to the underside of traditional
roofs, as well as those constructed from steel, asbestos and aluminium. Systems
can be applied to various depths and have a K-value of 0.023Wm2K. When
sprayed to a depth of 85mm the U-value of a typical roof with 100mm fibreglass
at ceiling level is reduced from 0.34W/m2K to 0.16W/m2K, bringing your home
up to current (2006) Building Regulations. This can save the equivalent of more
than 1 tonne of CO2 per annum in reduced energy consumption.
Hybrid Warm-deck
Pitched Roof
(No breather membrane)
U-value: 0.16w/m2k
To avoid the expense re-roofing a house that is simply suffering from nail fatigue,
and to obtain optimum insulation, an 85mm layer of polyurethane foam can be
sprayed onto the underside of the slates or tiles of a pitched roof. This stabilises
and weatherproofs the roof by fixing the nails, battens and roofing felt. As the
foam is a superior insulant, coupled with just 100mm of insulation at joist level,
your roof will also meet the stringent thermal performance standards required for
a new home. A typical roof can be insulated using the polyurethane treatment
for around half the cost of re-roofing. The insulation at eaves level will leave your
loft area comfortable for use and free from condensation.
By installing the insulation at rafter level, it keeps the loft void warmer and
prevents condensation build-up, which can otherwise occur when increasing
insulation at ceiling level. The warmer, drier, cleaner roof space eliminates the risk
of pipes and tanks freezing.
Some 150,000 properties have been treated with polyurethane foam insulation in
the UK. There are systems which have British Board of Agrément approval for use
in existing and new build applications and can show compliance to Building
Literature on the use of sprayed and injected polyurethane for walls, lofts and other applications is available from the British Urethane Foam Contractors Association,
based at PO Box 12, Haslemere, Surrey GU27 3AH; or tel: 01428 654011; fax: 01428 651401; e-mail: [email protected]; web: www.bufca.co.uk.