Expansion Gaps In New Plywood Subfloor Missing
As part of a structural repair to our townhouse we replaced the footings, posts, beams, joists and subfloor in and around our kitchen. We told our contractor we planned to install an engineered hardwood floor and to prepare the subfloor accordingly.
The plywood is 3/4Ã¢ÂÂ Hard Sturd-I-Floor attached to 4x6 joist on 16Ã¢ÂÂ centers with adhesive and 2-3/8Ã¢ÂÂ x .113Ã¢ÂÂ ring shank nails. The original 2x6 joist allowed for too much floor bounce due to the long span so we upgraded to 4x6. The upgrade to 4x6 joist improved the floor dramatically.
I was reading about proper subfloor installation and I see a minimum 1/8Ã¢ÂÂ expansion gap should be provided along all seams. When I looked at our plywood subfloor I see our contractor butted all the seams tight. See pictures below. Is the 1/8Ã¢ÂÂ expansion gap for the plywood subfloor mandatory to avoid problem with our planned engineered hardwood floor?