3 Essentials for Your Flat Roof

Flat roofs are a common feature on house extensions, garages and many commercial properties. While they have the same essential purpose as a pitched roof – to keep water out – there are a few differences in their structure.

In this post, we’ll look at three must-have features for any flat roof if you want to protect whatever’s underneath.

1.   Waterproof covering

The most important feature of any flat roof is a waterproof covering that keeps out the rain. While pitched roofs use tiles or slates, on flat roofs the waterproof covering can be provided by a variety of membranes including liquid systems, fibreglass coverings and single ply sheets or felt.

Whatever the case, the waterproof membrane will need to be regularly checked – and repaired or replaced when necessary – to ensure it provides comprehensive protection for the roof. Compared to pitched roofs, which last anywhere between 30-100 years, flat roofs need replacing every 10-20 years, and it’s best to have them checked annually to maximise their lifespan.

2.   Dry decking

Decking is obviously a must for any flat roof, providing a surface where the waterproof covering can be applied. But it’s also essential that this decking is dry. This goes without saying for new flat roofs, which will feature brand new, dry decking.

However, far too many flat roof repairs will leave the decking wet. When the waterproof surface is penetrated, rainwater will be able to get into your flat roof’s structure for days, weeks or months until it’s fixed.

Some contractors will simply patch up the damage and recover the surface. Leaving the decking wet will leave the flat roof weak and vulnerable to further damage. Instead, it’s essential that any damaged decking is replaced with fresh, dry decking.

3.   Slight fall

Despite the name ‘flat roof’ suggesting they’re completely flat, flat roofs also need a slight fall to work at their best. According to British Standards for construction, flat roofs should have a minimum fall of 1:40 at design and a finished fall of 1:80. That means for every 40 or 80 cm across the surface of the roof, it would fall by 1 cm.

To put that in context, pitched roofs have a much steeper gradient of between 1:3 and 1:2. This slight gradient in the roof’s structure allows water to run off much easier. This avoids water standing or pooling on your roof, minimising the risk of leaks and excess weight on your flat roof.

Flat roofing experts

Flat roofs are quicker, easier and more cost-effective to install than their pitched alternatives. But that doesn’t mean they should be done on the cheap. At DPR Roofing in Pontefract, we know everything there is to know about flat roofing – from the essentials to the smallest details.

From flat roof felts to liquid roofing systems, we use a range of materials to provide new flat roofs and roof repairs tailored to your budget and requirements. That’s all completed by an expert local team with over 30 years’ experience in the industry.