A sagging roof is not only a problem that looks bad, but it can also be bad for you and your  family . Usually, the roof should be flat or there will be a slope in the middle. But a sagging roof means that the structure of the roof becomes curved or wavy. 

It is normal for a house that has not been changed or maintained for a long time resulting in sagging. Another reason is structure design. If the structure design is not correct, then this problem will occur.

A roof which  is sagged indicates that the roof can collapse. Today’s content is about to solve this problem. Now the question may arise in your mind,  “how to jack up the sagging roof”.

Well, if you want to get a complete idea about the answer to the question, you have to read the whole content carefully. 

Keep reading. 

Why is the roof sagging?

Apart from structural problems, there are many other reasons for roof sagging. There are some crucial reasons behind sagging the roof of a house. The reasons are discussed below.

How To Jack Up A Sagging Roof

Water damage

Water is not only the cause of roof sagging but is also responsible for many roof problems. So, to protect the roof from water damage, there should be a good drainage system. 

As a result of water damage, the problem of roof sheathing starts, and then for the remaining water droplets, Wood damage causes roof sagging.

If you use low-size materials.

Low-sized materials are another common reason for roof sagging. Suppose you need rafters of 2 × 6 size for your roof, but you use 2 × 4 size rafters instead. Then the roof will be sagging.

Sometimes if there is no bracing or not enough, then there is a possibility of hanging the wall which may be the cause of roof sagging.

If there is excess weight on the roof

Excess weight can damage the structure of the roof as stress will apply then. During the winter, snow or ice on the roof can damage the roof structure. 

Although almost all roofs are built in such a way that they have sufficient capacity to withstand pressure, excess weight can destroy the internal structure of the roof and turn it into a sagging roof. 

If you use plastic roof sheathing, then the accumulated snow can be removed every day.

If the roof is old

If the roof is used for a long time, then the structure of the roof will become brittle, as a result of which the roof begins to sag. 

The old roof maintenance cost is also much higher, so not everyone maintains properly for which the roof hangs. 

Before you know how to sag a jack-up roof, you need to know the reasons why the roof is sagging. Because it is important to know what to do before the problem arises. So, you can be aware of this fact in the future.

How to jack up a roof sagging 

It is not an easy task to fix a roof that has been sagged, rather it is a very difficult task. The condition of the roof becomes worse. Moreover, even if the roof is old, it sags, so the roof is in a fragile condition. 

If you are not confident to do it yourself, then you can get the job done by a professional or a roofer. And if you are confident that you can do it yourself, there is a solution in this content.

Necessary tools 

  1. Chain
  2. Leg screw
  3. Turnbuckle
  4. Nail
  5. Hammer

Step by step guideline 

Step 01:

First, we have to keep the walls of our house firm and stable. Because if it is kept tight, then it will be convenient to jack up. Attach the two side walls to the chains with leg screws. 

You can use one or two chains if you want, but it is better to use two chains as you have to hold the wall tight. Now use the turnbuckle to equalize the pressure between the two chains.

Step 02:

Now you have to maintain some process to jack up along the ridge beam. In the middle of the room, with the ridge beam, two posts should be attached to raise the ridge beam. 

Then slowly jack the ridge beam of the roof. And whenever you jack up, you have to tighten the chain.

Step 03:

Then keep repeating the process of jacking up the ridge beam. And keep doing it slowly. You must know that the jack-up process takes a long time.

Do a maximum of 1 “jack up every day, otherwise, the structure may break down if you do a sudden jack up. Do the total process for 1-2 weeks, then hopefully there will be no problem.

Step 04:

If you do not have a rafter tie on the ceiling of your house, then apply it which will protect you from any further type of roof sagging. Then when you finish jacking up with the ridge beam, stick the posts well with nails. 

Now your ridge beam is jacked up and there will be no roof sagging problem. This is one of the most widely used processes of how to jack up a sagging roof process. This will allow you to easily complete the task yourself.

Frequently asking question and answer 

Can a sagging roof be harmful?

Yes, the sagging roof will cause damage to you and your family. Since it has a structural problem, the structures are usually fragile, so it is better to be careful.

Can I fix the roof sagging myself?

It is normal to ask this question. Yes, you can fix your sagging roof yourself if you follow the rules mentioned above.

How much does it cost to fix a sagging roof?

How much it will cost to fix depends on what you are changing and the price of those materials. However, it will cost around 700-2000 to fix your sagging roof.


A sagging roof is a roofing defect that is caused due to some reasons.I already  have discussed in detail how to solve this defect in this content. 

Roof sagging fix is ​​a difficult task and is very time-consuming work. When jacking up the ridge beam, do it slowly so that there is no problem with the working process.

Surely, you have got the answer to “how to jack up a sagging roof” without any complication in the content.

You should maintain your safety. Since the fixing process has to be done on the ceiling side of the roof, you should work with caution.

Hopefully, all the questions and problems have already been solved through this step by step guideline.

Best of luck.


As a civil engineer and roofer, I love to share the experience that I have gained through the last couple of years. In the roofing industry, practical experience is a very crucial fact that can help you a lot. Hence, I want to help you with my blog.

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