Flat roofs – Yes or No?

Are you considering an extension? Has a flat roof been proposed? Have you considered implications?

Have you already got a flat roof or are purchasing a property with a flat roof; do you know what signs to look out for?

First of all, do you know that there are different types of flat roofs? We discuss the main types in a little more detail below:

1) The most common system used is a built-up felt. This is installed in layers as a ‘built up’ system suggests. It starts with timber decking, then built-up felt layers are installed which are over-lapping. The system overlaps to try and provide a watertight system. The quality of felt can vary greatly, this system is also dependent on workmanship and quality. This system is expected to have a life span up to 10 years.

2) Another common type of flat roof covering is asphalt. This is a mixture of bituminous pitch with a gravel or sand aggregate. It is quite durable but can be prone to cracking. This system is expected to have a life span up to 10 years only.

3) The other systems installed in the UK tend to be less common although there usage is increasing. Elastomeric (EPDM) system can have a lifespan up to 50 years although most warranties will be given for between 25 and 30 years.

What to look for if you are reviewing a property that already has a flat roof?

1) Damage or weathering to the upstands.

2) Areas of standing or ponding water.

3) Does there appear to be drainage channels? Are they blocked?

4) Is there any solar protection, this can be in different forms but most commonly seen as solar paint or chippings.

5) Is there any lifting, bubbling or cracking? Does it feel spongy to walk upon?

6) Can you see flashings at abutments? What condition do they look in? Is there any cracking, visible damage or lifting?

7) Have you checked inside of the building? Is there any water staining even if it is historic?

So you’ve taken a look at the roofs and you’ve seen some areas that are questionable. So What should you do?

1) You should check if there is any documentation relating to when the roof was covered or recovered.

2) Make enquiries with the vendor to gain as much information as possible.

3) You should contact a surveyor or roofing specialist to undertake a survey and provide a specification of works to make the roof water tight again. The surveyor/contractor may be able to also undertake thermal imaging and core samples to fully identify the extent of damage below the initial surface.

Contact our team today to discuss any issues, find out more information and organise a site inspection. We can inspect any properties across the UK as we are happy to travel.

Our offices are based in Littleborough, Rochdale.