Hi guys,

I'm reading installation requirements, and many solid hardwood manufacturers (specifically Pollmeir Beech in this case) say not to install below-grade.

I have a 4 level, split-level home. My basement and crawl-space are concrete and I do not plan to change their flooring. My lower level is above the crawlspace, about 3 feet above it, and about 3 feet below ground level. It has the same joist and osb floor construction as the rest of the house.

Does this make my lower-level below grade? Can I use solid beech here? I can't see how an additional few feet make a difference. Is the manufacturer meaning that I shouldn't install it on a below-grade concrete basement floor?

Thanks,
John[/code]

The slab must be 3" above soil level, or it is considered below grade. If any part is below that spec, it is below grade.

I don't think I've been clear. Maybe a picture will help, I'm not familiar enough with the terms to describe this properly.




Thanks for your help guys,
John

Your lower floor is below grade. It is below soil level. Soil level is called "on grade"

A matching engineered may work well on the lower level, but your really risking it with a solid wood.

I had no idea it could make such a difference to flooring. Glad I asked, thanks for the tip.

You could do a subfloor moisture content test to all the wood subfloors and that should give you an idea if the lower floor area has a higher moisture content than the other areas. Also, use a humidistat to test and monitor humidity levels throughout the varying levels in the home. If the humidity levels are higher when you get below grade, it is an indication that exterior moisture vapor is intruding inside your home through the concrete foundation walls and/or slab floor. It should be noted that nearly all flooring manufacturers do NOT recommended any solid flooring be installed below grade, which is the soil level outside the structure.

Is the crawl space ventilated?

Sorry for the delay getting back to you Jerry. The crawlspace is ventilated and connected to the finished basement. The furnace is in there, and there is quite a bit of air circulation. There's a ~6" duct near the furnace which provides fresh air from outside. I was told this is because we have a fireplace, not sure why.