I'm helping my in-laws with unglued tongue in groove laminate flooring. there is a minimun 3/8 to 5/8 inch space required. The sheetrock doesn't reach the floorand the gap is large enough for the flooring to fit under. Will it cause a problem to have a larger space by going in front of the sheetrock. We don't want the flooring to shift.
Also it says to seal the cement and then put down a vapor barrier, is the sealant a must?
In my opinion a sealant and vapor barrier are both for the same reason and it does seem redundant. One or the other should be fine. Although if you do ever have an issue the manufacture would most defiantly have a "out" of any warranty if you choses not to follow the instructions. Leave the full gap recommend! One of the biggest problems I have seen on laminate "floating" style floors is they will buckle up if they don't have the expansions space. I have yet to see one slip or shift. Remember it is one sheet threw the whole room or area when it's done.