DIY to fix Bouncy and Sagging Floor

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Is your floor looks like bouncy or sagging due to the stone and tiles of the surface are cracking up? Or your wooden floor is sagging or bending beneath your feet? It happens when your floor is flexes or bounces because the subfloor is too thin poorly supported by beams and joists or inadequately attached. Sometimes the problem can be easily fixed by driving a screw through the subfloor or into the joists but, at many times it may involve more structural extensive work to support the foundation or floor to fix the problem.  We are here with some common methods for improving the rigidity of the floors without requiring a structural engineer.

Maximum Joist Spans

If you’re feeling that your floor is generally weak besides having adequate thin subflooring then the joist is undersized. You should then need to check your local building codes but, if they are placed 16 inches apart then your joist may be too small.

Home tips: you can attach plates of panels or reinforcing metal gussets of ¾ inch plywood to repair a crack joist. Else, you can use a long screw that can penetrate most of the width of the joist without pocking on the backside of it.

How to add a support beam

If you suspect a floor sagging joist so don’t try to drive an additional screw through the flooring as this can have sometimes the unfortunate effect of pulling the floorboards by making the finish flooring dip instead of becoming supportive and stronger.


Quick tips: you can cut the sister joist out of 2 by lumber that should be at least 6 feet long and it has to be of the same width as the original joist. Press it up against the bottom of the floor. Hold it for a temporary time in a single place by welding vertical 2-by-4 support. Now, drive pairs of 3-inch wood screws to secure the sister joist to the original joist.

How to Install Blocking

If you want to fix the sagging floor by strengthening the entire surface. So, you can install blocking between the pairs of joists of the same width as the joist of 2-by stroke. Now cut their pieces so that they can fit snugly perpendicular to its joist.

Now all you need to access the underside floor from the crawl space or the basement. Measure the distance between the joist carefully by numbering them if feel necessary.


Now, tap the blocks between the joists by using a hammer. Stagger or offset each block from the one next to it by 1 or ½ inch to make screwing or nailing into the end. Use a 16d nail or 3 inches screw to secure the blocking of the joist to support the floor.

Add a Modeling Bridging

The steel bridging doesn’t add a much strength as blocking but can provide a measure on cut down into squeaks and reinforcement. Moreover, they are easy to install as compare to blocking.


You just need to purchase a steel bridging piece to fit the space between the joist. Wedge each piece tightly into the position and then nail or screw through each hole. Now put them into the place to support the floor.


The best way to fix bouncing and sagging the floor is to install a new support structure such as jacks.

You can use the home measures that we have mentioned to support your floor and to make them strong for years.


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