10 Common Problems with Flat Garage Roofs

Flat garage roofs are widely used, as they give the garage a neat, modern finish, and a high performance solution.

And, when installed correctly and well-maintained, your flat garage roof should remain extremely weather resistant, durable and energy efficient, for many years to come.

But, since garage doors are isolated from the rest of your property, it can be a while before you notice a problem.

And then, when you do eventually spot the issue, it will have escalated to a much more costly issue.

So, to help you know what to look out for (and so get the issue fixed as quickly as possible), we’ve outlined the 10 most common problems that we see in flat garage roofs.

1. Standing Water

Also known as ponding, standing water is the name for water that has been allowed to stand in the same spot for a considerable period of time (48 hours or longer).

This is most commonly caused by a slight dip in the flat roof, which allows the water to pool. If the water is not removed from the roof, and does not evaporate, then it will wear down the membrane of the roof, and eventually seep through the roof into the garage.

As you can imagine, this occurs far more commonly in flat roofs than pitched roofs. And, if left untreated, it could cause serious damage to your garage roof, to your car, or to anything else positioned directly underneath.

Proactivity is key to removing the risk of standing water. Keep your garage roof well maintained, and make sure any blockages in your gutters and drains are cleared quickly.

Then, if you do see ponding, dry it out using rags. If it is a particularly large area of pooling, or there are numerous points of pooling on one roof, then book a specialist to take a look at the issue.

2. Plants & Moss

If moisture has been allowed to build up, then plants and moss can quickly grow on the roof. This most commonly includes weeds, fungus, lichen and moss.

You can treat this issue with weed killers and a bit of elbow grease. Then, to prevent it from happening again, keep an eye on the water retention of your roof. In particular, see if you can spot instances of standing water.

3. Water Marks

Another common consequence of standing water is watermarks. If water has been allowed to seep into the roof, or has been standing in that spot for a long period of time, then it can leave patches staining the roof’s surface.

The best treatment for this depends on the type of garage roof that you have. It might require a repaint, replacement tiles, or another type of targeted repair.

4. Rusted or Lost Roof Nails

If the garage is older, you might find that any exposed nails have rusted over time.

If this occurs, they could fall out of the roof, or provide an entry point for water to seep through into the garage. Thankfully, this issue is quick to spot, and can be quickly fixed by a roofing specialist.

5. Blistering

This issue gets its name because it has a very similar appearance to the blisters that we get on our feet.

This is when a blister-like bubble forms within the roof membrane. It’s caused by water, which is trapped under a layer of the membrane. If it bursts, water will be able to seep directly into your garage.

It’s an issue that needs to be treated by a roof specialist. It could be that your roof membrane needs repairing or replacing.

6. Cracking or Stretching

Over time, a garage roof can develop cracks or stretches, particularly in the roof’s joints or corners.

This occurs when the flexible materials in its waterproofing layers stretch, wear down, rip or dry out (which causes cracking). If you do spot this issue, then a roofing specialist will be able to offer specific treatment advice, depending on the condition of the roof membrane and the extent of the problem.

7. A Moving Wall

Although a small degree of movement is unavoidable, if subsidence or land heave occurs, then the building’s structure can move significantly. If this does happen, then the garage roof will stretch, causing tears and cracks.

If this does occur, it is highly likely that your garage roof will need at least a partial repair, and it might require a full replacement.

8. Build up of Debris

Because the garage is separate from the rest of the house, it can be a while before you spot the build-up of debris.

Leaves, sticks and other bits of debris can quickly build up in a garage’s guttering or on the flat roof.

So, with flat garage roofs, we suggest arranging a regular cleaning schedule. This will ensure debris is removed before it builds up into a bigger issue.

9. Poor Quality Repairs

If you’ve inherited your garage from a previous occupier, then it might be that they’ve attempted to fix the issue with a botch job.

One thing that we commonly see is that they’ve spotted standing water on their garage (after it was there for some time) and cleaned it up, without realising the extent of the problem.

If you suspect a poor quick-fix repair job, a roofing specialist will be able to offer you a second opinion, and advise you about whether it could cause future problems.

10. Punctures

A faulty installation could mean that nails or screws puncture the waterproofing membrane. This, if not fixed, would then provide an entry point for water.

If this does occur, then the membrane will need repairing.

If you are experiencing any of the garage roof problems listed above, then the Zap Garage Doors team is here to help. We can fix any of these issues, and ensure that your flat garage roof is performing at its peak.

So, to find out more about any of our repair, replacement, installation, maintenance or consultation services, don’t hesitate to get in touch.