I have a sun room that was added on before we purchased our house that I am turning into an office. The sub floor is the enclosed concrete slab. I purchased engineered wood flooring that mirror the other flooring in the rest of the house. The office will have movable book shelves and a desk that will be set on top of the wood floor and I was worried that the weight might cause an issue if I installed a floating wood floor. Because of the height of my exterior door, I will have to choose between either floating or gluing down the floor.
Follow the manufactures instructions.
I suggest float. I recently replaced a hardwood floor in my home and did a lot of research. The floor needs to be able to expand and contract with the change in humidity levels in the house. Floating a floor will allow all joints to stay tight and not come apart during those dry times.
I think you will be good either way. I prefer gluing it because there are fewer thing that can go wrong and you do not need a T molding where the new floor meets the old hardwood. (because the floating floor can not be attached to anything and needs a gap around the entire perimeter to allow for expansion and contraction) You might need a reducer if the 2 floors are not the same height. One downside of gluing is for some stupid reason you have to tear up th floor it can be a lot lot lot of work. I am not saying floating is bad by an means. Its good for people who like to change their floors often because the removal is by far easier. Also if you do a lot of standing on the floor the little bit of pad under the floor gives it a softer feel. Just a side note, depending on the wheel system on the movable book shelves, the amount of weight, and how often you move the shelves are a concern. The engineered woods that I normally see can not handle a lot of abuse. And can easily get indented. you might want to consider protecting the floor where they move around or pick a different kind of floor.
Floating is probably the easiest and cheapest way to go. Make sure you have a good underlayment because you have two issues: the uneveness of the residual glue and the sound issues from the floating floor. You want the stuff that is more rubbery in appearance rather than the stuff that looks like packing material. There are some design issues to worry about (expansion gaps, carrying through doorways) with a floating floor that a good installer should take care of. Plywood and staples is what I have used in the past. The downside other than expense is that it will raise up the floor a bit and you'll have to deal with the transitions. I've stapled down lots of engineered floors without a problem. Glue is the worst answer. First off the stuff is Nasty (and not exactly cheap, I paid for my flooring stapler with the money I saved on the first flooring job). You must wait a day until it dries before putting the furniture back, etc... With the float or staples, you can just move everything to one side of the room, lay your half floor, move stuff immediately on the side you just put down and finish the rest.
The type of flooring you purchased will determine what you should do> If you have simple tongue and groove ,it should be glued. If you have interlocking ,it should float. Weight will not be an issue .Both types need a 1/4' gap at the perimeter for expansion and contraction.
