How To Stiffen Engineered Floor Joists

The method or methods tom chooses depend as much on practicality as on effectiveness.

How to stiffen engineered floor joists.

These days many new floors are framed with i joists a type of engineered lumber that s a fraction of the weight of conventional lumber and capable of spanning greater distances image 6 left. It was a complex expensive job. Contributing editor mike guertin teams up with structural engineer david grandpré to detail six common and not so common ways to stiffen up the joists and keep the china cabinet from wobbling. If you have access the joist spaces from below adding solid blocking between the joists at 4 ft.

Working in the unfinished basement below the bouncy floor we had to remove the plumbing and electrical lines running through the joists and then rerun the lines. To stiffen a floor system attach 19 32 inch or 23 32 inch thick wood structural panels to both sides of each i joist in the vicinity of the problematic area. Bouncy floors are one of the most vexing problems faced in houses both new and old. Years ago while working as a carpenter i helped stiffen a bouncy floor by nailing a new 2 10 to each of the 2 10 joists that supported the floor.

Q instead of glue and nails my framing subcontractor used screws to fasten the sheathing to the i joists of a new 14 foot wide addition. While there are no interior walls bearing on the floor system and no excessive notching in the i joist flanges and the joists fall well within the apa s allowable span guidelines my clients say their floor is excessively bouncy. But it will help in combination with sistering or plywood facing as described below. How to make floor joists stronger.

Use panels with the same depth as the i joist and install them with the strong panel axis running parallel to the joist length. Homes because the floor joists often are smaller or are spaced farther apart than the joists in modern homes. There are a variety of ways to stiffen a floor. For example sistering with new lumber the fix tom s dad used makes sense only if the joist bays are not cluttered with electrical cable plumbing lines and ducts.

Still if asked to span too great a distance i joists will bounce. A floor joist reinforcement. Long spans of joists in newer homes may wobble or bounce from foot traffic. Long span joists may meet design criteria and the build ing code yet still feel uncomfortable.

After several centuries of service floor joists in older homes may sag or crack.