After finishing off the clearance of the openings this morning, we then switched over to the other router, we tackled the next job of slicing 38mm wide vertical slots at the top of the walls to allow the roof rafters to come through. Using our specially made template (which hooks around a vertical post) to guide the router in the exact locations where there are vertical posts which is where we want each of the roof rafter come down and sit directly on top of the solid post for maximum strength and load bearing.
We managed to do wall B and Wall A (along the front of the building) and then Wall M and half of wall L (along the back of the building).
These rafters are coming down at an angle of 32 degrees which means a bird mouth of 37mm deep cut into the top flange of the rafter and hence the amount of cement board needed to be removed pass the line of the top-plate. This is to allow the rafter to lock onto the top of the walls in a very secure fashion and have plane of the roof exactly 60mm above the top-plate and also the edge of the cement panels (these are coming up to meet the roof boards).
Birds-Mouth-Cut
Sits-on-top-of-wall
and-passes-through-the-cement-board
in-a-Slot
On Monday, we will finish off the remaining walls that has these same 32 degrees sloping rafters (wall L, J, I, E and D). then the template is adjusted to do the next walls that has the 40 degrees angled rafters and finally the 45 degrees angled one after that.