We have been working on the sill plates and blocking for the roof rafters over the last week. We are using 3×8 dressed lumber for our sill plates (2-1/2″ x 7-3/8″ dressed), and attached them to the concrete bond beam using timber washers and nuts. Normally you would use 2×8 or 2×6 but we recovered some low grade material in our yard and this is the dimension we got. We plan to do the framing of the front wall out of 3×8 as well … it should be a nice look.
Going step by step …
Then we used a hammer to mark the locations of the anchor bolts on the boards …
Finally, we countersunk the holes so that no part of the bolt or attached nut stuck out above the top of the lumber. This was the hardest and often most painful part! We countersunk after drilling our holes up from the bottom of the wood. We did not countersink first as our marks were on the bottoms and the countersunk part of the hole is on the top of the board. The bit has a tendency to travel so getting the two holes lined up was occasionally a challenge … particularly when there was a knot. If the countersunk hole did not line up then we simply made the whole bigger. (WARNING: The bit is large and if it bites into the wood it tends to stall the drill out. The momentum has to go somewhere, and it tries to spin you around. Do not let go of the drill!)
As of yesterday the sills are attached to the front and back walls and the rafter blocking is also in place. Initially we had planned to block the rafters up one inch for every two running feet for a roof slope of 1 in 24 (1″ of rise over 2′). However, since we are using 2-1/2″ thick lumber we changed the roof slope to 2.5″ of rise over 24″. This made laying out the blocking very simple. We attached the blocking to the sill plates using 4″ log building screws spaces every 3′.
On the wall between the utility room and the kid’s bedroom I left a 2.5″ x 2.5″ clear channel through the blocking. We will run a gravity fed water line here to the cistern at the front of the building that will allow us to harvest rain water from the back of the roof.
This week we start framing the front wall and placing beams!