I think they are just regular nails. I know that when we had the house waterproofed from the outside, they had to dig around the outside of the house to put the draintile in. When they dug in the front of the house, they hit a very old dug well that poured about 3 feet of water in the trench that they dug around the house. We did not know that there was a well there. The well that we are currently using is in our basement. It's 55 feet deep with the water at the 35 foot level. The house I believe was built in 2 stages. The older part of the house I can tell because it has 10x10 or 10 x 12 beams in the basement and the floor boards are up to 17 inches wide. The part of the basement that is towards the back of the house where the flat roof is located, has standard width lumber.

Bob