Do you have dips or sags in your floor? We have listed 5 ways to fix a sagging floor to give you some ideas on your next possible move. Before you go too far, make sure you know the cause of the problem. The circumstances surrounding the cause of the sagging floor may be unique to your setting. We have made it a practice to consult a structural engineer first. The not only can diagnose the issue but they can also do the math to find out the exact sizing of supports to fix the problem correctly.

Once you know the WHY of your situation, here are 5 possible ways to fix a sagging floor. This is just a sampling of methods. There are quite a number of different ways to approach the problem.

Sistering Joists

Sistering involves adding additional joists alongside the existing joists to distribute the weight of the floor more evenly and help level out any sagging areas. This can be a relatively simple and cost-effective solution, but it may not be suitable for severe cases of sagging.

Pros:

• Can be a relatively simple and cost-effective solution
• Can help to distribute weight more evenly and level out sagging areas

Cons:

• May not be suitable for severe cases of sagging
• Requires access to the underside of the floor

Jacking Up the Floor

Using a floor jack to lift the sagging floor back into place can be an effective solution in some cases. However, it can be a labor-intensive process and may not be suitable for all types of flooring.

Pros:

• Can be effective in certain situations
• May be a quicker solution than other options

Cons:

• Can be a labor-intensive process
• May not be suitable for all types of flooring
• May not be suitable for severe cases of sagging
• May cause cracks to appear in walls and structure above

Installing Support Beams

If the sagging is severe, you may need to install support beams to help distribute the weight of the floor more evenly. This can be a more involved process and may require the assistance of a professional.

Pros:

• Can help to distribute weight more evenly and level out sagging areas
• May be suitable for severe cases of sagging

Cons:

• Can be a more involved and expensive process
• May require the assistance of a professional

Adding Shims

(see OTHER IDEAS section below)

In some cases, adding shims (thin wedges of wood or metal) between the joists and the subfloor can help to level out a sagging floor. This is a relatively simple solution, but it may not be effective in cases of severe sagging.

Pros:

• Can be a relatively simple and cost-effective solution
• May be suitable for minor cases of sagging

Cons:

• May not be effective in cases of severe sagging
• May not be a long-term solution

Repouring the Foundation

If the sagging is the result of a foundation issue, you may need to repour the foundation to level out the floor. This is a major project and should be undertaken by a professional.

Pros:

• Can address the root cause of the sagging
• May provide a long-term solution

Cons:

• Can be a major and expensive project
• Requires the assistance of a professional

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OTHER IDEAS

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Adding Floor Leveler

Another option for leveling a sagging floor is to use a self-leveling floor compound, also known as a floor leveler. This is a type of concrete mixture that can be poured over the surface of the floor to fill in low spots and level out the surface. Here’s a general overview of the process for adding a floor leveler:

• First, prepare the surface of the floor by cleaning it and removing any debris. If there are any cracks or holes in the floor, they should be filled and smoothed out before applying the leveler.
• Next, mix the floor leveler according to the manufacturer’s instructions. This typically involves adding the leveler powder to water and stirring until a smooth, pourable consistency is achieved.
• Once the leveler is mixed, pour it over the surface of the floor, starting at the lowest point and working your way up. Use a straight edge or a level to ensure that the leveler is evenly distributed and that the surface is smooth.
• Allow the leveler to dry according to the manufacturer’s instructions. This typically takes several hours or overnight.
• Once the leveler is fully dry, you can sand the surface to smooth out any rough spots and prepare it for finishing.

Pros:

• Can be a relatively simple and cost-effective solution
• Can be used to level out both small and large areas of sagging
• Can be used on a variety of surfaces, including concrete and wood

Cons:

• Requires some mixing and preparation
• Takes time to dry and cure
• May not be suitable for use on all surfaces
• Can add significant weight to the floor causing damage or collapse to a weakened or improperly supported floor

Adding Shims PLUS Adding New Subfloor

In some cases, it may be necessary to remove the existing subfloor and add shims between the joists before installing a new subfloor. This can be a more involved process, but it may be necessary if the sagging is severe or if the existing subfloor is damaged. Here’s a general overview of the process:

• First, remove the existing subfloor, taking care to carefully remove any nails or screws that may be holding it in place.
• Next, add shims between the joists as needed to level out the surface. This may require cutting the shims to size and fitting them in place.
• Once the shims are in place and the surface is level, you can install the new subfloor. This can be done using nails or screws, depending on the type of subfloor you are using.
• Once the new subfloor is installed, you can add the new flooring of your choice on top.

Pros:

• Can be a more comprehensive solution for severe cases of sagging
• Can provide a new and stable foundation for new flooring

Cons:

• Can be a more involved and time-consuming process
• Can add significant weight to the floor causing damage or collapse to a weakened or improperly supported floor
• May require the raising of molding and door modification due to interference
• May require the assistance of a professional
• May be more expensive than other options