sagging floor bowing bowed joists

Don’t let sagging floors get you down. Just like all of us, your floors sometimes need just a little extra support. This homeowner came to us with a visibly bowed and sagging floor in their first-floor entranceway.  A sistered joist or multi-ply beam installed underneath is typically the most effective solution for stabilization in this situation.

Using designs created by Cole Engineering, we were to shore up the structure and install Laminated Veneer Lumber beams (LVL) in order to provide more support to the upper level.

Of course, nothing is ever as simple as it seems.

The drywall ceiling was cut out in a 4’ by 4’ square during the inspection process. This allows the engineer make assumptions based on the size and placement of the floor joists above. Their plan included sistering LVL beams to existing beams to better support the weight of the flooring.

Unfortunately, when we began working, we found that many of the joists that the engineer had based their assumptions on did not run the length of the floor. Remember, engineers can only see what is visible at the time of inspection, which forced to make assumptions about the existing conditions. It was discovered someone had installed a number of spliced joists that did not run the entire support length. This meant we had to pause our work and have the engineer come up with a revised plan to ensure the repair was completed properly.


Problem solving

This new plan included sistering an additional two sistered floor joists at full length and complete removal of two existing floor joists. As well as install a new double LVL beam under a load bearing wall. The double LVL beam could not be attached to the floor above like the old joists because the floor above was now finished.

To solve this problem, we cut wood pieces and installed them perpendicular to the beam in between the old joists and the new beam. Bridging the beam like this will keep it from attempting to rotate and add extra stability to the floor.

Do you have floors that droop or sag? Don’t let your sagging floor get you down, contact us and let us help find you the support you need.


  • sagging floor, support, joists, repair
  • sagging floor bowing bowed joists
  • floor joists, beam