I have fiberglass in my concrete mix and a year later, I can't find any of them on the surface. There were a very few of them there in the beginning, but they rapidly broke off and were not a problem. I guess that if you go looking for them in the corners, you might be able to find a few, but that is rare. The floor was finished with a power trowel to a vrey smooth finish and that might be what made the difference. In the apron that has a broom finish, I still can see some fibers, but they don't hurt anything. Unless he will be working on the floor nude without a creeper, I don't think that any residual fiberglass is going to be a problem. In the event that he is working on the floor nude, then I don't think the fibers are going to be the only obstacle to getting done what ever the job is, the cold and dampness is. /forums/images/graemlins/grin.gif