Old House Floor Joists

I recently started work on a home built in the 1890s that has 2 8 joists on 16 in.

Old house floor joists.

In this post i ll tell you a bit about the floor joists and sill logs and how we kept the house as original as possible. You can clearly see that in the picture on the left. On the top side of the floor another fix it idea to lay down new hardwood over the existing floor. It seems that 2 8 rough cut joists were once used everywhere regardless of the span.

Well after doing the navy seal crawl up under the house we found that the joists that were supporting that floor were not actually attached to the sill plate any longer as seen in the photograph below. As a test firmly push a metal probe or screwdriver into the post at the floor line. Centers spanning 14 ft. Anyone who has ever renovated an old house has probably dealt with a floor system that is a bit too springy.

A plywood subfloor will bridge any minor waves in the existing floor and leveling compound would help too. If this area is mushy punky or rotten you may have found your problem. The sagging floor was the symptom and somewhere under the house there had to be a cause. As the posts slowly rot and melt into the floor the house settles accordingly bottom to top.

You will have to make sure your joists can handle the addition of considerably more weight from the plywood subfloor and any floor coverings.