11 flat roof problems to watch out for

Spend 10 minutes now with our simple guide to save you from hassle later.
Get a quote!

A common issue with roofs of any type is correctly identifying the problem when things go wrong. And, more often than not, that means stopping water from getting in.

The outer problem may not be anywhere near the point the leak becomes visible inside the house. Often water can sit between layers of roof materials for several months before actually escaping into the house. To make matters worse, water doesn’t usually come through the ceiling on a nice sunny day when you’re in a good mood to deal with it either! Problems often become apparent when heavy rainfall compounds an already existing problem. So it’s better to spend a short time up a ladder now, looking for those tell-tale signs of a leak, rather than dealing with them on dark rainy night in the depths of winter.

Here are 11 flat roof problems to look out for:

1. Ponding

As the name suggests, a pond of water on your roof is a very bad sign. Long standing water will always find a means of escape and that often means through the roof.

2. Watermarks

Water may have escaped into the roof or evaporated after a long period of ponding. Either way it will often leave the tell tail signs of patches of a lighter or darker colour depending on the surface you are looking at.

3. Vegetation

Moss, fungus, lichen and weeds are all signs that there has been a build-up of water.

4. Cracking or stretching at joints or corners

With age, the flexible materials that make up the waterproof layers of your roof can crack (due to drying out or stretching), rip or just wear away. This is most common with roofs made of rubber or EPDM (Ethylene-Propylene-Diene-Monomer).

5. Blistering

This is when you see a bubble appear in the roof membrane. One day it might burst giving water direct access into your home.

6. Movement

All properties suffer from some degree of movement but in most cases it’s minuscule. However, subsidence and land heave can often cause significant movement to a building’s structure. A moving wall will stretch the roof which will often lead to tears and cracks in the waterproof membrane.

7. Rusted or missing roof nails

Whilst not common on modern roofs, exposed nails on older properties can become a water entry point as they rust or fall out.

8. Dodgy repairs

The previous occupant may have fixed a leak in a rush during a downpour and forgotten to have it properly looked at. Make sure that all materials match and there are no odd patches of membrane or excessive sealant covering your roof.

9. Punctures

Keep a close eye on anything added to your flat roof which uses nails or screws to hold it in place. Not only does it provide a route for water into your house but it might also void the warranty from the roof installer.

10. Not enough roof angle

Flat roofs shouldn’t actually be 100% flat. There must be a slight gradient for water to flow off. Ideally between 1 in 40 and 1 in 80. At that gradient it can be very hard to spot, so buy or borrow a meter long spirit level to check the angle. You can use it to also check that there is no sagging in the roof.

11. Remove debris

It’s good practice to make sure water can run freely in all the guttering around the house and also across the flat roof so remove all debris.

Prevention is better than cure. Whilst your insurance should cover you for any major problems, an incident might affect your future insurance premiums. Always check direct with HomeProtect if over 30% of your roof is flat, as we can offer competitive flat roof insurance quotes where other insurers ramp up the premiums.

You should also check that you have full details of the roof installer who built your flat roof and if they supplied any form of guarantees or warranties. If you’re just think of upgrading or adding a flat roof it is always worth paying the extra to hire a reputable roof installer.


Get a quote for your flat roof insurance online

Get a quote!