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5 Causes Of A Sagging Roof (And How To Repair It)

Inspections are important to do if you see a sagging roof. But what to look for that may be the cause? Here’s what to know and how to fix it!

5 Causes Of A Sagging Roof (And How To Repair It) - ACR

Your roof is such a crucial part of your home. It’s what protects you from the elements, so you need to be sure that it’s in the best condition possible. A roof in good condition should be totally level, so if you’re seeing sagging in your roof, that’s a cause for concern. Here’s what’s causing it, and how you can put it right.

1. Water Damage

This is probably the most common reason why roofs start to sag. Your roof is exposed to the elements all year long, and so it’s dealing with wind, rain, snow, and more. Water can really do a number on the roof, as it can get in and start causing damage. This includes allowing wood to rot, so the structure of the roof becomes damaged and the roof begins to sag.

2. Weakened Roof Structure

When your roof was first installed, the wood used in creating it was in its best condition. Over time though, the wood in the structure has taken on damage. That can be water damage as described above, or it could be a number of other things. For example, if they’re incorrectly positioned, then that can lead to sagging. Pests such as termites can cause damage to wood too, creating more problems overall.

3. Bad Workmanship

When you’ve hired a roofing service to take care of your roof, you want to know they’re doing their very best. If you do your research and look for the right team, you should have the best people to help you get a quality roof installed.

If the workmanship isn’t of the best quality though, you’re then going to deal with the issues that causes. If items aren’t installed correctly, that’s going to cause a knock on effect on your roof. For example, if you have your attic converted into a room and the roof lights aren’t installed without appropriate support, that’s going to lead to sagging.

4. Excess Weight 

This is another very common reason for roof sagging, as it can happen very easily. Excess weight usually comes from snow, when it settles on your roof. The added weight of that snow will be more than the roof is designed to take, and so it will start to sag under it. Left long enough, your roof could even collapse under that weight.

5. Ageing

While a roof may have been installed perfectly, it could be that its age is causing it to sag. Over time, the roof materials are going to wear out, and they won’t offer the same quality as they once did. If your roof is over 30 years old and you’re seeing sagging, that’s a sign that it has come to the end of its lifespan.

How to Fix And Prevent a Sagging Roof

Now you know why your roof is sagging, you can start work on repairing the damage. Knowing what is causing the sagging is vital though, so if you’re not sure it’s always best to call in the experts, so they can diagnose the problem for you.

Do Regular Roof Inspections

The best thing you can do for your roof is to make sure you’re doing regular inspections. If you’re keeping up with them, you’ll be able to spot any issues quickly, before they can get worse. That’s good for you, as the repairs are likely to be easier and cheaper, too.

Start your inspection from the ground, looking at the outside of your roof. You’re looking for anything that’s damaged,d such as missing or broken shingles, broken flashing, and so on. You’ll also need to get up into your attic to see what’s happening on the inside. You’ll be looking for signs of damage in the rafters, as well as any light shining through the roof. That will be a sign that shingles are missing and need to be replaced.

Keep these up, so you can ensure that you’re catching problems as and when they happen.

Brush Snow Off the Roof 

If you’re in an area that gets regular snow, you’ll want to keep an eye out for snow settling on it. This leads to extra weight issues, as well as the possibility of ice dams. The best way to get snow off the roof is with a snow rake. These can be operated from the ground, keeping you safe. When you do use them, ensure that you’re taking care with them, so you don’t knock shingles off the roof.

Hire the Right Roofers

You can avoid all kinds of problems if you hire the right roofers to come and take care of your roof for you. While there are many roofers out there that do top quality work, there are plenty of others that won’t. To ensure you’re getting the best people, talk to friends and family to get recommendations, and check sites like the Better Business Bureau to see what they have to say about companies in your area.

Avoid Water Damage Where Possible

While your roof is always going to be under siege from the wind and rain, you can ensure that the roof has the best defense. When you do your inspections and see things like shingles or flashing missing, you can repair them ASAP. That ensures that chink in your roof’s armor is sealed quickly before any water can get in and cause damage.

Replace Your Roof 

If the roof is sagging and it’s over 30 years old, then the best thing to do is have it replaced. While you could repair the roof, you don’t know how long you’ll get from those repairs before you start to see sagging again. It’s better to have the whole roof replaced, so you know your home is protected.


As you can see, there are all kinds of ways how a roof can start to sag. If you take action quickly though, you’ll be able to put it right. Always call the experts to diagnose the problem and help repair it, and your roof will be as good as new.