I plan to install engineered hardwood floors over a concrete slab. Should I glue it down or float it? Any other pointers for this job?
Float it for sure, this allows for any expansion or contraction during the seasons. Just to be on the safe side I would put a coat of concrete sealer/water barrier on the floor. Get the best underlay pad the you can get, it does make a huge difference. The biggest thing is to let the flooring sit in the rooms for a day at least to let them weather for your room and not the temp of the wear house. It doesn't sound like a big thing but it is. Have fun doing it.
No matter you float it or glue it, make sure the floor is flat. Check with floor guy, I know someone found a very expensive glue which can stop moisture too.
if you got the wood look and see if you have random length board any were between 4ft to about 12 if you have that then you have to glue it and to glue the concrete has to be clean and level and make sure you're moisture content is low in the concrete you could rent a moisture meeter to check it and use the right glue and install every thing tight to each other and make sure you have enough expansion around the perimeter but make sure the 1/4 round will cover good luck
Not all engineered floors can be floated, check with the manufacteur first to see their approved methods. Either way you need to do a moisture test of the concrete first. duct tape a 1 by 1 piece of plastic to the floor and wait 24 hours then remove and see if there is any moisture built up if there is do not install or it will buckle.
Glued direct to the concrete will give you a better, more solid sound. It will seem to be more substantial and better quality glued down because of the solid sound. Most concrete slabs are smooth enough if you scrape up all paint over spray and drywall patch. Do test for moister. Do use the glue that the manufacture recomends, don't cheat and buy the cheap glue.
