I have 3/4 x 3 inch Cumaru. Is it best to top nail these rows or can I just glue down with liquid nails urethane or Pl400? thanks!

If the material is straight enough, you can glue the remaining rows. I would not use any construction adhesive with "urethane" on the label. Pl 400 would be better.(or just regular liquid nails.) If the material is back coated, you need to buy a Moisture cure urethane flooring adhesive. You can find Bostiks Best at Home Depot in a 2 gallon pail.

Chuck why would you not use urethane ? and wouldent liquid nails stop the wood from expansion and contraction ? or is it designed to move ..

Thanks for the repy! Stupid question but how do I tell if the boards are back coated? Looks like plain wood on the back to me.

If it has been back coated, you will know. It is shiny.

Flooring guy,
"urethane" is a throw away term. Construction adhesives commonly CONTAIN moisture cure compounds but they are not even close to being pure urethane. Elongation properties are a big deal. You need an awful lot of real urethane solids to get that. That will not be found in a tube of PL polyurethane. Solvent based adhesives offer more elongation than the current brand of "urethane" construction adhesives.

Do not take my word for this. Ask the manufacturer about the elongation characteristics of each adhesive they offer.

Glue stop? That would be a neat trick.

I have no reason to doubt you Chuck , was just trying to learn .. thanks for the reply ..

Thanks again. I have one additional question. do I apply the adhesive to the back of the board and attach it to the roofing paper, to the tongue of the board or take up the roofing paper and apply the adhesive to the subfloor. How much adhesive do I apply? thanks!

Jason, cut back the felt and run a good wavey bead of adhesive directly on the subflor, you may have to use some wedges or blue tape to keep the seams tight until the glue sets up.

You may also want to "dry fit" these runs first before you glue then pull them out in order put down the adhesive then ley 'em in. May be a needless step to some (and more time consuming) but beats discoverring that you need to retrim a piece that has glue all over the back of it .... messy.
have fun,
Will