Real Estate

What are the Causes of Roof Sagging and how can you fix this Issue in Downey?

Learn a few basic tips to deal with the issue of roof sagging

The roof plays a major role in determining the strength of your house. Hence, you need to protect your roof by taking good care of it. You can inspect your roof and get the issues fixed as soon as you notice any roof damage. If you are confused about how to inspect your roof to detect the issues then you can contact a professional roofer in your location.

If you are searching for a reliable Downey roof repair specialist then you can contact Thompson Roofing in Downey. We deal in all types of roofing services that include roof inspection, roof repair, and roof installation. You can choose the services as per your requirement. If you notice your roof sagging then you can contact us to hire our professionals to get your roof repaired. So, let us understand the sagging roof issue and find out how you can fix this issue.

Causes of sagging roof:

Water Damage 

If you are staying in an area where you experience heavy rainfall then you might face issues like roof damage. If you do not maintain your roof regularly then the problem worsens. So you need to facilitate the proper water drainage to ensure your roof is in good condition. You need to install metal flashing on the junctions to facilitate water drainage. If you do not check your roof regularly, it might cause the issue of roof damage. Poorly designed gutters are one of the reasons for a sagging roof.

Poor ventilation in the attic

If you have installed your attic poorly then you can face water damage issues on your roof. If attics are not properly ventilated then it will not facilitate airflow and will cause moisture build up in the attic and water can enter your roof through the attic and damage it over time. This type of water damage leads to a sagging roof. Replace the flashing, clean the gutters, and improve the ventilation of your attic to get rid of this problem. You can also install angled braces to correct the sagging.

Roof Design flaws and snow accumulation

Each roof is structured to withstand a certain weight, which might cause damage issues if the amount of weight exerted on the roof exceeds the recommended capacity. In the winter season, we experience a lot of snowfall. When excess snow gets accumulated on the roof it creates pressure on the roof and thus causes roof damage. Moreover, when the snow melts it turns into ice as soon as the temperature drops at night. This further gives rise to ice dam formation on the roof, which exerts more pressure on the roof thereby creating roof sagging issues. This might cause serious water damage and water leakage issues on your roof. You can install new rafters to deal with the design problems of your roof. You can also remove all the shingles and install new ones to get rid of sagging issues.

How to fix a sagging roof:

Identify the Problem

First, you need to inspect your roof to identify the underlying problem. You have to find out the sagging area on your roof. You can inspect your roof decking and rafters in those areas where you notice sagging. Then inspect the plywood gusset which is installed in the area where wood connects to a truss. You need to identify all the damage including rot and crack.

Fix the Rafter or Truss

To fix the rafter, you can use the ‘L’ channel to bring back the rafter into its original shape. You can drill four holes in every side of ‘L’. Remove pieces of wood with the chisel and mount the ‘L’ into the rafter at the end. Fasten the end of the channel with washers and bolts in the holes that you have drilled earlier. Move the broken piece into place. The gap between the rafter and the channel should be 1 ½ “– 2”. Then tighten the bottom bolts farthest from the crack. Tighten the back bolt until it is close to the channel ad then tighten the front bolt until the rafter becomes secured. Follow the same procedure with other holes.

Fix the Gusset Plate

To fix the gusset plate, you can remove and replace the plate with a new plywood gusset. Attach the gusset to all the sides of the wood using nails.

Fix the roof decking

You can hire our professional roofers to repair a damaged decking. Cut ½ inch piece of plywood to cover the damaged area between rafters. Then glue the foam onto the plywood and place it keeping the foam side up. Place the plywood on the roof decking. Push the plywood until the foam touches the roof decking. Maintain the plywood position until our roofers reach you to get your sagging roof fixed.


A sagging roof is one of the major causes of roof decay and roof damage. Hence, you need to check for possible water damage after a snowfall or heavy rain. This will help detect if there is any water damage on your roof. If you are confused about how to fix the water damage then you can take the help of our professionals to get your queries resolved.