Ask the Experts: What is a Flat Roof?

‘What is a flat roof?’ is an interesting question and the answer is not as obvious as it may first appear. A flat roof should never be truly flat but have a slight gradient to allow for water runoff. As a leading flat roofing supplier, what we don’t know about flat roofs isn’t worth knowing… let’s look at the question in further detail to see how to tackle your projects.

The design and manufacture of a flat roof

A high performing flat roof starts with the design and planning. Whether you’re thinking about adding a flat roof extension or putting a new flat roof on a garden building, this stage is critical. Think carefully about the materials you’re going to use during the planning and determine your priorities.

Flat roofs are often constructed using timber framing and decking but can come in many different forms. Concrete roofing, for example, was popular in the 1970s and 80s on garages and commercial properties to increase fire safety.

Unlike pitched roofs, flat roofing is designed with a 1:40 gradient in mind and it is typical for this to be up to 1:80 once construction and installation is completed. This gradient can also be achieved with the use of tapered roofing insulation boards installed on top of the roof deck and beneath the waterproofing membrane.

Waterproofing is of the highest importance in flat roofing, which historically has been ill-performing and one of the biggest reasons for the traditional unpopularity of this type of roof. Modern waterproofing systems however, such as EPDM, have revolutionised flat roofing and now single-ply roofing membrane is one of the fastest growing sectors in the UK.

Further reading:

Waterproofing a flat roof yourself

Many homowners will have the flat roof deck and timbers installed professionally, but often tackle the waterproofing themselves. When it comes to covering a flat roof, EPDM roofing membrane is widely available and among the best flat roofing materials on the market today. It has a proven high performance over an exceptional life expectancy of more than 50 years, unmatched when compared to more traditional flat roofing materials.

For DIY waterproofing, EPDM offers a range of benefits:

• Fast and easy to install
• Single piece with no joins (up to 15.4m x 30m)
• Available in a complete flat roof kit
• Requires little or no maintenance
• Suitable for a range of surfaces
• Exceptional cost vs. value over extended lifespan

PermaRoof UK stocks everything you need for trade and DIY flat roofing from high performance membranes and adhesives to insulation to skylights in our one-stop shop. We also offer industry-leading customer support and a library of free installation guides and video tutorials to help you get it right first time.

Related products to buy online:

Installing an EPDM flat roof

Remove the existing roof covering and prepare the surface, removing any grease or oil spots using a solvent-free cleaner. Once the roof is prepared, lay out the membrane to rest for 30 minutes. This allows packaging creases to dissipate. Installing EPDM rubber on a flat roof is a straightforward process. Watch the video below to see for yourself…

Video guide: How to install an EPDM flat roof:

Here at PermaRoof UK, we support all our customers and answer a variety of flat roofing questions every day. If you have a question, please visit our FAQs page, give us a call on 01773 608 839 or use the live chat for a quick query.

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