How to fit Flat Roof Insulation

Flat roofs aren’t known for their durability, so it’s important you take the necessary steps to maintain them and fit them with flat roof insulation.

flat roof insulation

If your building or business is fitted with a flat roof, you may find yourself having to replace it much more frequently than you’d prefer. But if you’re keen to keep with a flat roof then you should definitely invest in some flat roof insulation. This will at least ensure that it is more energy efficient and more effective at keeping the cold out – and the heat in. You could save up to £190 and 800kg of CO² a year if only half of your roof is flat, and even more if your entire roof is flat.

Follow these four points of advice if you’re planning on fitting some flat roof insulation:

1. If possible, install flat roof insulation from above

It’s a fair bit trickier to install insulation below the roofing, and it can cause problems with condensation. Ideally, a layer of solid insulation board should be attached to the roof’s layer of weatherproofing or on the timber roof surface with a layer of weatherproofing put on top of that. Also, it would be more cost-effective in the long run to replace the flat roof completely at the same time, rather than trying to alter the one you’ve already got fitted.

2. Be prepared to cover the entire cost yourself

Unfortunately there aren’t any energy grants available to help with the cost of fixing flat roof insulation, so you must be able to cover the entire cost yourself. Get in touch with a professional installer to get a quote on how much it will cost to fit your particular roof.

3. Thoroughly research the three different main types of flat roof insulation

The main types of flat roof insulation are: warm roof, cold roof, and inverted roof. A warm roof is where the deck of the roof is below the insulation. A cold roof is where the roof deck is above the insulation, and there is often a ventilation gap to protect against condensation. An inverted roof is where the insulation is above the weatherproofing layer, protecting it from extreme temperatures which can shorten its lifespan. All three types will hugely increase your building’s energy efficiency, so whichever one is used will depend on what is most useful for your particular building and whatever your preference is.

4. Unless you’re a professional installer yourself, don’t attempt to fit it yourself

Fitting flat roof insulation can be a complex, time-consuming job which will depend on the type of flat roof that you have. While there are many parts of pitched roof insulation which you can attempt yourself, unfortunately flat roof insulation will require a professional installer to fit it according to industry standards.

Image: Knauf Insulation

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