I am tiling over a ceramic tile underlay. What happens if a nail is protruding bey about 3mm?

Question

My husband thinks that the adhesive will take up enough room between tile and underlay to not have to worry about punching all the nails in completely. Is this true? What will happen if we just go straight over the nails that are still protruding a little bit?

Answer 1

My husband and I just had a new tile floor installed. Our floor squeezed very badly. Nails over time loosen up which causes the underlayment to move. When the underlayment moves so do your tiles causing cracks in the grout. You definately have to punch the nails and put 21/2 inch screws in the subfloor.

Answer 2

Tile Underlay

Answer 3

I agree with k h. Nails will pull out over time, causing movement in the subfloor. Not only will the grout lines crack, tiles may also break when pressure is applied---like the weight of someone's step. I would hammer the nails down much like you would when nailing sheetrock (a slight indentation of the nail head), then to ensure the flooring is secure, I would screw the flooring in place also. Then you'll have the peace of mind, knowing the flooring isn't going to pull away.
Good luck

Answer 4

Use a hammer or a punch to nail the nail back in place, then use a screw or ring-shanked nail to make sure the nails don't loosen. Never use a regular nail for flooring. The ring-shanked nails have ribs on them to keep them from pushing back up. However, I like screws better because even ring-shanked ones can protrude back up on occasion.

The nail protruding is due to the floorboard moving up and down. You should refasten the floorboard down with screws first to keep the board from moving up and down. Then nail or use a hammer and punch to make sure the protruding nail is nailed flat. Otherwise, you are going to risk your ceramic cracking.