Laying floor on a subfloor that has old plumbing holes in 3 places. The biggest one is just 2 inches, the rest are smaller. Otherwise the floor is in excellent condition.
I'm using ditra. Is it necessary to cover up the holes to lay the new tile floor on top. I'm using small porcelain tiles on a mesh matrix.
If it is necessary to cover the holes, would a thin piece of wood veneer do?