Warm Roofs
Before - the flooded United Reformed Church flat roof in Colindale, North London
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Also before - as you can see, the water had nowhere to run off
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The tapered warm roof insulation being laid
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The top coat of liquid polymer roofing system being applied
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'Warm roofs' explained:
So - what is a 'warm roof', and what is the difference between a 'warm roof' and a 'cold roof'?
'Warm roofs' are being installed by more and more property owners around the UK, in line with 'U-values' brought in annually by local and central government. All roofs should be insulated, with insulation thickness depending upon the insulant used and whether you're creating a cold or warm roof.
'U-value' measures the rate at which heat transfers over time through a building element (e.g., the roof) under standardised temperature and wind conditions. The better your roof retains heat, the lower the U-value.
With warm roofs, insulation is either placed between the roof deck and the weatherproofing (i.e., above, not below, the roof deck) or laid using decking with insulation pre-bonded to it. No ventilation is required, although to prevent cold-bridging, the external wall insulation has to be extended upwards to the bottom of the roof insulation.
'Cold roofs', where insulation is placed between the flat roof joists with gaps left for ventilation, simply cannot get down to the kind of U-values now required (unless the joists are constructed super-deep and topped with a concrete roof). As with warm roofs, the external walls need to be extended up to the bottom of the roof insulation as a prevention against cold-bridging.
Furthermore, a warm roof can be insisted upon by building control, particularly in cases where the joists in a new extension are unable to ventilate adequately because they are against 'a second abatement' (e.g., a wall)
A Warm Roof Refurbishment in action:
The United Reformed Church in Colindale contacted us regarding an urgent job on their single storey roof in North London NW9 (see slideshow above).
The flat roof was flooded, as the pictures show, with no way for the surface water to drain.
After installing the tapered warm roof insulation, the first base coat was applied, followed by the top coat was applied, with tapered falls to two outlets being created to avoid future flooding.
The work was completed quickly, leaving the United Reformed Church warm, dry, and leak-free in a matter of hours!
You can view the designs here, including condensation risk analysis and U-value calculations.
To find out more about warm roof refurbishment, contact us FREE on 0808 144 2055 or drop us an email - we aim to reply to all emails within 24 hours and can answer almost any roof-related questions you might have!
Remember to take a look at our roofing discounts and deals tab on the right - you could get your new warm roof for up to 30% less!