A customer tiled a 200 sq. ft. commercial bathroom floor. 12″x24″ tile with 1/8″ joints was specified. After layout he’d have had 1″ cut, so he opened joint to 3/16″ to eliminate small cuts at perimeter.
He should have, but didn’t consult the architect before making the change. The architect is unhappy, since they hadn’t been consulted before the adjustment. Is there anything in ANSI or TCNA regarding adjusting layout to avoid small cuts? I recall that topic during the presentation on the advanced installation accreditation tests. Where would I find that?
In ANSI A108.02.4.3.8 and in the TCNA Handbook in “Grout Joint Size, Layout, And Patterns” section, it talks about minimum grout joint size. Was the 12″x24″ installed in a brick pattern, or running bond pattern? Was the tile used calibrated or rectified? There are minimum grout joint requirements for this pattern depending on tile type.
Depending on a couple factors, the TCNA Handbook states “The actual grout joint may, of necessity, vary from the grout joint size specified.”
ANSI A108.02.4.3.2 states “An excessive amount of cuts should not be made. Usually no cuts smaller than half size should be made.”
You are correct he should have communicated with the architect before making this change, if the architect did specify a different grout joint size. The statements above could possibly help the defense of his layout depending on pattern, tile type, and actual facial dimensions of the tile.
You may also reach out to the manufacturer of the tile to see if they have a minimum grout joint size recommendation that could also aid in his case.