I have removed original carpet from 2 rooms in a 1990 house. It has 3/4" T & G plywood subflooring. There are a few squeaks that I think that I can fix with screws in a few isolated places. In one area without squeaks, two adjacent joists have most of their nails raised nearly 1/8", so that removing them would not be very hard with a claw hammer. Should I remove them and replace with screws, or hammer them back in and add a screw? If adding a screw, how should I place the screws, centered, or adjacent to the nail?
At two plywood corners, one sheet is raised almost 3/16" for about 6" along both edges. I have not worked on it to see if that can be pulled down with screws, but unless advised otherwise, I plan to try.
One joist is cracked at the end of s sistered joist. The sistered joist ends near the middle of the span, and is there as the support for a bay window that extends out 2' farther than the normal joists. Now seems like a good time to add another scab joist for reinforcement. That is one place where there is a squeak, as would be expected. Is an 8' reinforcement appropriate?
The subflooring is glued, because in many places glue oozed out onto the joist. The nails are spaced 6" apart. In two rooms, one 20' by 15' and the other 15' by 12', a couple of squeaking nails is not too bad. It is the ones that are now raised from drying wood (I guess) that I am wondering how to address.
From the underside, the raised part is down tight against the joist, so I think that sheet was water damaged and swelled before installation. I squeezed it down with screws only slightly.
The cracked joist has a gap at a knot and is visibly cracked halfway up the height of the joist, which is a 2" by 10". There is not much strength there.