we are replacing our kitchen floor due to waer damage. The'contractor', that we haven't seen in 2 weeks, laid down 3/4 wafer board to replace the old. We are putting down Armstrong @10.98/sq yd and now that the flooring is beginning to adjust itself to the shape of our floor, we can see all the nail heads. What is the right type of wood to have put down in the first place? We are on a crawl space if that makes a difference. Or what can we do to protect the flooring from the nail heads?