Decided on 3 inch solid unfinished cumaru for entire house installed on raised foundation with new plywood subfloor. I live in Southern California about 5 miles from ocean. Large swings in temperature or humidity shouldn't pose a problem. Floors will be finished on site using oil based poly.

The flooring was delivered 2 days ago and the installer wants to let it acclimate for 2 weeks. Is this enough time? I've heard horror stories of cumaru gapping due to humidity mismatch and other issues. He said he will apply a sealer prior to the poly. The floor is bundled in stacks roughly 8 inches high. Should the flooring be spread out to expose all the planks to properly acclimate?

Any words of wisdom and advice is greatly appreciated.

I think 2 weeks is plenty of time. Although, spreading out the wood a little might help, I do not think it is necessary.

Acclimation is not a set time line...it's a matter of testing the sublfoor, material , and environmental conditions.

You want to bear your child midstream, errr the median RH level of your particular zone. There's zone maps out there if you need them.

Solid Cumaru can be ready to go right off the boat or it could take months to get it where you want it to be m/c wise. Its one of those floors I wont sell in a solid with any kind of guarantee what so ever. I know in east Tn that Cumaru does not do well in the stability performance area. cumaru over an open crawl space spells trouble around here just fyi. Stunning appearance and density but its one fickle pickle imho.