We are finally done building the subfloor for the first level! After some hiccups with the steel columns that delayed us a bit, we are ready to move on to framing for the first floor walls. The columns are all bolted in above and below the steel beam, the wood I-joists are all in place with rim boards and blocking, and the floor sheathing has been glued and nailed down.
Installing Wood I-Joists
For the first subfloor we had to install 11 7/8″ deep wood I-joists at 16″ on center with a double joist (two joists nailed together) at the edge of each cantilever location. The first step in this process was to get all the joists placed in their locations and set one edge straight before cutting the other ends to size. The I-joists we ordered came in standard 28′, 30′, 32′ sizes and needed to be cut to the correct size for our project.
Around the perimeter of the subfloor we had to install 1 3/4″ LSL rim board to tie everything together. The rim board will serve as the line for the outside edge for the floor sheathing and outside face of our exterior walls so it was important to make sure that the rim boards were placed straight, level, and square.
Blocking Between Joists
Another key element to building the subfloor is the blocking. Our structural engineer requires us to install blocking at every 32″ on center between the first two rows of joists at both ends of the house and at every 8″ on center between all the remaining joists. For this we used the extra ends from cutting our joists and nailed them between the joists to serve as the required blocking.
After installing all of the required blocking, we moved on to the floor sheathing. This part of building the subfloor went smoothly because we installed joists every 16″ on center which meant the 4’x8′ OSB floor sheathing edges ended on a joist. Having the floor sheathing end on a joist meant we did not have to cut any of the plywood except at the end of the subfloor since our plywood edges landed on a joist every time. This makes for efficient use of our OSB and makes gluing and nailing in the sheathing much easier.
Now we are moving vertical! With building the first level subfloor complete we can now move on to framing the walls. Stay tuned for the next update on our custom home build and check out our YouTube channel Tekton Home Construction for the latest videos and updates on the construction process!