Originally Posted by idonutn0
This weekend I started an install of 5/8 inch wood floor. There are a couple of spots where the floor sags up and down when I step on it. The flooring was laid over the cement slab and an underlay material.
What is the best way to fix this problem?
Thanks for the help.
Hi! I just dealt with this issue myself. First, are you sure the cement slab is 100% level? You can use a laser level in the dark to scan it and see if it is true, or a long ordinary level. If it is not level, you may want to either have it ground down or level it with abocrete, or a similar self-leveling epoxy to make sure you are installing your floor on level.
We just dealt with this- we had our cement slab ground AND a self-leveling epoxy applied! Then over that we did plastic sheeting, mold fighting foam, a 3/4 plywood subfloor, now we have put in our solid oak planks which we hope to finish with a tung oil varnish. We also had to take out and re-hang two doorframes and doors. Yay. It's been two weeks of lovely labor but now that we are driving the pegs into the floor (my husband is a purist, and the house is 1900-1920 vintage) I can see the final product.......
The other possibilty is warped boards if you are working with engineered strips. You could try replacing those boards and see if that helps. Certainly wold be cheaper.