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How to Fix a Sagging Floor

A sagging floor is one of the most common complaints of old-house owners. If you experience a constant bobbing up and down on your floor each time you walk on it, then you have got a sagging floor. But not to worry because this article is here to guide you on how to fix a sagging floor and get your floor back to its shape.

The existence of a sagging floor only indicates that there is a bad wood under your flooring that needs to be fixed. It can also be that one of your supports is decomposing or that your foundation is faulty.

Are Sagging Floors Dangerous?

Have a sagging floor in your home is quite dangerous. Not just to the house, but your health and other aspects of the home. These are some of the reasons why you need to fix a sagging floor as soon as you notice it in any part of the house:

Causes Mold Buildup

A sagging floor can get exposed to moisture over time. This in turn will turn it into a breeding place for mold and other bacteria. There are several health complications associated with exposure to mold over time. That includes throat irritation, wheezing, chest tightness and other health complications.

Affects the General Beauty of the Home

Flooring is one aspect of a house that adds to its general beauty. A sagging floor generally if not beautiful to behold and thus will affect the general beauty of the house.

Affects Resale Value of the Home

When a realtor discloses to a potential buyer that your home has a sagging floor, it will affect the price of your house. This alone can drop the value of your home down to 30% of its original value.

Signs of a Sagging Floor In a House

 There are simple signs that will help you determine if your floor is in a state of danger:

  • Cracking on the Interior Part of the House
  • Windows and Door Problems
  • Lack of Support
  • Sloping Floors
  • Bouncy Floors

If you observe these factors, then you need to read more on how to fix a sagging floor because you possess one. You can also inspect your house to be sure of what you are dealing with. By doing that, you simply need to wear protective clothes and gloves with a touch light and a respirator if possible. While you are in your crawl space, check out for insect hives or excessive moisture. The inspection will help you get a direct solution for your sagging floor.

Sagging floors are prominent when it comes to floating floorings which can serve as a discomfort. Sagging floors emerge in a house when the support beams of the house start to fail. They fail due to mold and wood rot which damage wood frames and floorboards. The mold occur as a result of the damp, moist air and wet crawl space environment, which breaks down with time.

Even concrete materials tend to crack and break after years. Floor joists hold the entire weight of your framework in a home and when this support structure damages then sagging floors will surface.

Tips on How To Fix A Sagging Floor

There are different measures on how to fix your sagging floor, but each step depends on the type of damage involved. The most common methods are.


You will have to troubleshoot the area to determine the damage that needs to be solved. Although saggy floors are visible on the floor you still need to measure from the floor to the ceiling across the entire floor. The troubleshoot will help you analyze precisely the point of the sag and the suitable method to fix it.

UnderFloor Examination

You will have to make use of productive measures with a bright torch to ensure that your inspections on them are perfect. Check joists and on breakages.

Footings and Post Support

Any footing in a house should be made to be strong. Making a concrete footing is the best as it will support the joist and hold them back. The concrete foundations will be firm if you dig down 2 feet deep and place your footing support in it.

Bridging the Floor

In this solution, you can install a new hardwood floor on top of the floor. It can serve as a leveling compound or a bridge. The joists should be stable to handle a big weight before this takes place.

Joist Sistering and Girders

Joist sistering is better than scabbing. Sistering involves using an identical piece of wood to fasten the floor joist and make it stand more firm. When the identical lumber is bIt provides adequate and extra support to the floor joist. A girder can be added to a sagging beam but Should be underneath the floor and beam.

Add Reinforcing Metal

You can repair an existing framing member by adding a reinforcing metal. These framing members can be joists or roof rafters.

Beam Replacement

Once you have a sagging floor, the structural damage can affect all of the wooden farming under the house. With this, it is important to replace or support any structural beam that is shaking or sagging.

Structural Jacks and Beams

In a situation where there is a long joist span and where the structural layout is poorly planned, it can cause a saggy joist. The beams are not to be too far from each other and when they are, they are stressed and constantly taking all the weight and gravity of your home.

What Causes Floors to Sag

Most times it is the framing materials we use for our foundations and most times it is what is later exposed to these materials that are in use. The causes can be seen as:

Poor Structural Support

A faulty support structure design is a common factor that each home tends to encounter. Your floor starts sagging when the floor joists start to bend due to excessive weight. You can thereafter make use of structures kike jack to fix it.

Moisture Problem

Moisture might find its way into your foundation and cause sagging to your floors. To prevent further damage, you should learn to dry out your crawl space and seal the leaks from the outside elements.

Massive Weight

Your floor can sag if it is constantly exposed to heavyweight. When this happens, you should install many jacks to support the massive weight. Push piers can be an alternative to keep the foundation stable and firm.

Fix Sagging Floor Crawl Space

A crawl space acts as a support structure that guides the entire first floor. It is this same support structure that consists of beams and floor joists that can be damaged due to excessive moisture and weight. When this happens, they cause the floor to sag and become incapable to hold the floor above.

When this happens, you are left with the option of fixing the crawl space to prevent it from moisture and weight. These need to be controlled for the floor to maintain its original state. You can fix sagging floor crawl space by:

·         Crawl Space Jack: Installation of this fact can help lift your sagging floor. You need to map out the location for each crawl space jack support. You then have to place the precast footing. This will be a leveled ground that will serve as a stable and solid base for the jack. Then cut the jack posts to length.

Once installed, it should be cut to length to fit. You can then assemble and tighten the jack while mounted against the girder. The final stage is then to seal all the damaged crawl space vents and an airtight crawl space door. The lining of the floors and walls will follow suit.

·         Concrete Columns: The beams and girders are in most cases supported by columns made out of concrete blocks. When the column is built and the mortar cured the extra spaces will be filled with wooden spacers or shims. It can be time-consuming to get the whole process done. The completed column will not be adjustable which might lead to it being refilled when needed.

·         Additional Shimming: This fixing method is a cheap one. This method is for repairing a girder and floor that have been sagged because of settled concrete columns. A crawl space jack has been placed on it temporarily to lift the girder. Wooden shims are then pushed to existing columns before the jack is removed. This is for a short term purpose because the concrete columns will continue to settle.

·         Light-Duty Jack Posts: These are light and skinny jack. It is adjustable when installed on a concrete block on the crawl space. But the jack holds a little weight and has a low stability rate. They only settle for a small lightweight environment.

How Can I Strengthen My Joists

Joists may sag or crack but above all, it is not easy to replace. Because of this reason, it needs to be maintained. You can do that by strengthening the joists. You need to add the length of wood to the existing joist which is known as sistering. Also, you can reduce wobbly floors with block inserts between the joists which are known as blocking.

Sistering Joists

Before purchasing a joist, make sure you purchase the type of lumber that matches the width of the existing one. You should measure the width and length of the existing joist to get a matching one. Cut a new joist according to the length you measured. Using an adhesive, squeeze it on the wide side of the original joist. If the adhesive has not gotten to all the parts of the joist, then use a plastic putty knife to spread it.

Place the new joist into the original one and drive in 16D nail every 16 inches through the new joist. Repeat till it moves around.

Blocking the Joists

Get a span of two joists and measure the width. Cut the lumber according to the width. Use the two joists to cover the lumber block and make it stay in between them both. Nail it in with a 16D nail on each side of the blocking.

You should repeat the nailing every 24 to 36 inches around the joists.

 How Much Does It Cost To Fix Sagging Floors?

The amount it costs to fix a sagging floor depends on factors like the total measurement of the floor space, materials for repairs. You will spend less if you want to do the repairs yourself. But on average, it cost $1,000 to $8,000 to repair a 300-square-foot room. The majority of that amount will be spent on buying materials and payment for labor. You can pay as high as $150 per hour for labor or less.