Hi there. My local flooring guy recommends Mapei 980 over Bostik BEST. Supposedly Mapei holds the ridges better than Bostik. Is this true?

When I checked out the 980 datasheet I noticed it can be only be used for wood up to 3.5" wide. My engineered wood is 3 9/16" wide. Can I still use 980 or should I then move up to 990?

Yes, the Mapei holds the ridges way better than Bostik's BEST. Now, Bostik's BST holds ridges pretty well.

I personally like the Mapei better, especially their WFM moisture blocker.
980 will be fine for that engineered. It is the solid gluedown that is going to take the 990. Engineered is way more stable. I have glued 5" engineered with 980 and didn't think twice. If you can use an acrylic on engineered, 980 is better than that stuff.

If you can get the Chemrex CX-1000 I would use that over Stauf any day. Mapei is so so mediocre adhesive IMO.

It does my heart good to see that tuscon guy helping out a diy'er trying to do something right . I haven't used the 980 but the 990 worked well for me. I aim to give the Chemrex a try if my distributor will bring it in.

J~Rome....hehehe Someones gotta give options to Uncle Perrys hit_n_run advice.

Plus I'm back on my meds but don't think for a minute this will happen forever.

Hit & run, is better then striking out. You didn't even go down swinging