Simple steps for replacing old tiling
Today the manufacturers have gotten flooring installation down to a science with special products designed for use under these difficult conditions. For example, there are special tongue and groove wood floors that are installed over a special paper. The literally “float” over the substrate using no adhesive at all!
Back to your question… you just couldn’t inject enough glue to make a lasting repair. Plus there is probably dust and dirt under the floor that would prevent the glue from sticking well, even if you could inject enough. The only lasting repair I know of is to take the loose sections of floor up, clean all dust and dirt from the slab and reglue. You will have to sacrifice at least a board or two to free up the others in the loose area. Here is a short description of the procedure…
First, you will have to remove one or even a few of the strips to release the rest from the tongues and grooves. You should be able to decide which and how many pieces to remove by looking at how they overlap.
Drill a number of holes into a selected strip. Then break it into pieces with a wood chisel
and remove it. Another method would be to use a hand circular saw with the blade set so that it does not penetrate the boards completely… again breaking the strip up. PLEASE be careful with the depth setting of your circular saw and also with your drilling… the concrete below will destroy drills and saw blades and, even worse, a circular saw may lose a tooth or kickback! That can hurt!
Now that you have removed the loose flooring, the following steps should be followed:
(1) clean up any dust or debris under the floor.
(2) apply a flooring adhesive to the floor and also apply a thin coat (called “buttering”) the back of each strip right before installation.
(3) Install the replacement flooring, piece by piece. You can start from either side, but I have found that starting from the side that has a “tongue” rather than a “groove” makes for a slightly easier repair. However, I understand that may not be possible in some situations.