I have been advised to use an Adhesive underlay for fitting my floating hardwood acacia floor. Has anyone used this method? I will be installing on an existing floorboad sub base wich is level and solid. I was originally goining to float the floor by gluing the tongue and groove. Is acacia pretty stable and or will I be expecting much movement, does it take glue well? Sorry about all the questions but I really want to do it properly.

Thanks

Is your floor a solid product? If so it is unlikely you could float it. While some people now seem to endorse gluing down a solid product, I have to disagree.
If what you have is a solid floor, not engineered; and you have a conventional wood subfloor, why wouldn't you be nailing the floor in place?

Who's advising you? Do you mean you're being told to do a glue down install instead of floating the floor?

I just glued this solid teak to concrete! You mean I shouldn't have !!!???

There's ALOT of solids being glued down these days successfully. I was brought up believing unless it was shorts, this was tabu. These days depending on the product , and done correctly.... I look at it differently.

I have solid Acacia 90mm wide boards of varying lengths. The room is split into two about 3x4 meters each half and so I don't think I'll get to much expansion and contraction, plus I don't think that the whole floor will be that heavy and so I feel that it should move as long as there is room at the edges.
My original intention was to float it on decent underlay and gluing each and every t and g. However a flooring shop advised that I should use a self adhesive underlay if I am not going to nail. The reason I don't want to nail, is that the sub floor is typical floorboards and I have central heating pipes running underneath, for the length of the two rooms. i once fitted an oak floor on plywood subbase over floorboards, a 3mm gap appeared for the whole length of the install where the client had heating pipes that neither of us knew about. I'm fitting this floor in my own house and I would personally like to float on underlay, but if I have to float on self adhesive underlay, then I guess I'll take that route???

You should not float a solid floor.

There are some exceptions out there...Junkers & some Bamboo ( although that's a debate whether some Bamboo is solid or engineered ).

in Europe Junkers clip floors are installed over a lot of slabs, got 60m2 of 20.5mm American oak installed by the clip system in my own home.

Ya well of course the clip system doh, c'mon, I mean gluing the T&G. There's also gonna be some solids with the 5-g coming out soon if not already.

Is that a LL Teak Ernie? If so, any comments?

I plan to see an engineered LL install sometime the next few weeks.

Video Review!

Yes Ken, it is the solid teak, 3/8 glued with BB and MVP. Actually nice stuff, but better have some straps with ya.

Every specie of the Bellawood installs different. Factoring in the drying, and who milled that specie . Some actually are a pleasure to install.
But give the Koa a shot

Up until about 1 1/2 years go ( for 6 years ), 75% of what I installed was Bellawood.

Guess where my Strap Clamp site idea came from

Keep in mind the species of wood you are using as well. Some woods are very stable and are not subject to movement as much as others. True Teak is like that. That is why Ernesto could successfully glue that solid down. Plus, it's a 3/8" instead of a 3/4". This is similar to the solid 5/16" Bruce and Hartco floors that can be glued directly. While I generally do not favor gluing a solid down directly to concrete, if it is in the manufacturer's installation recommendations, then one would hope the manufacturer has done the R&D to ensure a successful installation. One still needs to concern themselves about moisture vapor being emitted from concrete so the proper vapor barrier needs to be used. MC urethane adhesives are NOT moisture vapor barriers and I'm confident that's why Ernesto used MVP as well as BB adhesive. As long as the floor is not subjected to extreme swings in RH, that install should be fine. But I would not try it with an unstable wood like maple.