Fitting the new Flat Roof on extension – What size slope?

When fitting our flat roof, one of the main things to take into account the degree to which it would slope. A good fall on the roof helps stop rainwater from ponding or settling on it. Not only would this be unsightly but it can always deteriate the waterproofing.

But what pitch exactly? A good place to start and get some idea is by looking at the rule book, The Building Regs! Building regulations states I need to have a minimum slope of 1:80 but it also recommends creating a steeper slope at 1:40 – So this is what I will be aiming for. To achieve this fall we are laying firrings on top of the ceiling joists. Firrings are like tapered pieces of timber, which you can lay to achieve the fall on the roof and can be purchased from most builders merchants or timber yards.

Although sometimes cut on site, our local timber merchants already had them pre-cut so this saved us time and money, not to mention we didnt have to rely on our guys to cut them without any discrepancies.

Now the timber is all down and in place we can start laying insulation and get ready to lay our waterproofing. Once the rain stops of course!

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