Our real problem, then, is not our strength today; it is rather the vital necessity of action today to ensure our strength tomorrow.
-Dwight D. Eisenhower
The realization that the means to deepen a crawl space are limited to a pick-axe, a shovel, a five gallon bucket and a whole lot of manpower can weigh heavy if you don’t shift your thought process. We found that the best approach to the breaking the monotony of fill-bucket/ empty bucket was to utilize the time to envision the future of the space. In shifting to this way of thinking we found it critical to start from the ground level and build up from there. We truly believe that it would be irresponsible to do the type of finish work we strive to do without creating a strong and true structure to support it.
As we dissected the layers of floor structures in the addition it became self-evident that the best means to our eventual ends would be to start over from scratch. The best way is often the farthest from the easiest. There were limited elements worth preservation: the stone foundation, the mud-sill and the two large (unsupported) timber girder beams. To properly preserve and utilize these features we had to be creative in our approach to re-framing the space. The layout presented challenges as it was not plumb, level or square; and also allowed limited depth for framing materials.
The two girders divided the area into three rectangles. The two largest rectangles ran about two thirds of the length of the space and were about eleven feet and eight feet wide. The final rectangle spanned the width of the two and was approximately six feet deep (no pun intended, this one was actually in decent shape).
We began by attaching a 2″x8″ rim joist to each piece of the original framework using 1/2″ bolts every 32″. We were limited to 2″x8″ material for the framing because of the size of the mud sill, which sits directly on the foundation. We decided to use pressure treated lumber in this area because of the potential for moisture. From here we attached floor joists perpendicular to the rim joists, using galvanized steel hanger brackets, every 16″. We added blocking between the floor joists every four feet. The blocking serves two purposes: first it stiffens the joists and second it supports the seams between the subfloor panels.
Our next phase was to conceal all of our hard work with our subfloor. This is where the new strong structure becomes rock solid. We chose to go with 23/32″ tongue and groove Advantec. Advantec is a dimensionally stable composite board that resists moisture well. We glued the subfloor to the framing and nailed it every 6″ using galvanized 10d ring shank nails.
Reframing the floors was a huge and very much unexpected undertaking. When all is said and done we will be able to confidently move forward knowing that we have a strong, sound and secure first floor to build upon.