Flat Roofing FAQs

How long should a flat roof last?

It depends on the material you use, but if your flat roof is installed correctly it should last for at least 10 years, and at least 20 if a material other than felt is used.

How does rain run off a flat roof?

Flat roofs should be built at a very slight incline. This will allow rain to drain off the roof, and prevent ponding.

How can I maintain my flat roof?

You should inspect your roof twice a year, ideally after rain or snow, to see if it’s draining properly.

I’ve got ponding on my roof. Do I need to replace it?

Ponding is where you see pools of water appearing on your flat roof. Unless your roof is leaking or showing other signs of damage, you don’t need to replace it. When you do have your flat roof replaced, tell the contractor so they can find out the cause of the ponding.

I had my roof replaced but it’s still ponding where it used to. Why?

If you didn’t tell your contractor that there was a ponding issue, then they probably didn’t look at resolving it. To fix ponding, they would have to remove decking and joists and fit a new waterproofing system. It could double the cost of the job, but if your decking has deteriorated it should be replaced.

What guarantee or warranty can I get?

Most material warranties come from the waterproofing layer manufacturers, and can last between 5 and 20 years. If your roofing contractor is on the manufacturer’s installer list, it might cover their work. It’s important that you always read through all the information given to you about your warranty so you know exactly what is included.

What is overlaying?

If your existing roof is still in good condition but the membrane is getting old, it’s often not worth exposing the structure to the weather whilst the contractor strips off the old membranes. The contractor will leave them in place to act as a base layer for a new roofing system. As long as there are no other problems with your roof, then overlaying is a good way to replace your flat roof.

If you have any more questions about flat roofing that aren’t listed here, fill out our form to ask a contractor.

Emily Rivers

Emily Rivers is the Customer Experience Manager at Quotatis. She informs customers of the latest developments in a range of products so they can make the best choice for their homes and ensures they get the best out of our service.