After we finished off doing the wheels for the scaffolding tower, we continued preparing the bits and pieces for constructing the LVL Hip Rafters for the PA, EH and HI corners. We sliced a 26.6° wedge off the ends of 12 strips of the plywood webbing, making sure that the better side was towards the gluing direction (I.e. facing inwards). Then, the next job was to sort out the LVL timbers and labeled them so each one it is now determined for the correct role, three longer pieces for the top flanges and the three other one for the bottom flanges.
Next is to take the two top flanges that are going to have the bird mouths cut into them and start marking out the complicated shape of the cut-away section. We decided to do a practice run on a spare bit of 89mm CLS timber rather than the precious LVL timber. So we sawed the bulk material away and used a mixture of our wiggle saw (officially called an oscillating multi-tool, but what a mouth full!) and hammer & chisel to carve out the concave angled groove so it can sit tight over and on the outer corner of the top plate (see pictures below).
Corner-birdsmouth-cut
Corner-birdsmouth-cut-on-corner-piece
While we were looking at this complicated cut-away (double checking) on the computer, and also inspecting the actual Top-Plates on the walls in the corners of the house to make sure that we didn’t have missing timber which may meant a weaker joint (it turns out that all six affected corners were fine), we had a light-bulb moment! It suddenly it occurred to us that the pointed part of the corners on the top-plate could be removed to make a flat area for the rafter’s birds mouth to sit against flat .. WITHOUT any complicated inward groove! Phew!
So the rest of the afternoon was spent on the computer to update the drawings so that all the six corners around the house will have regular ninety degree birds mouth cut-outs and instead, a measured and angled chunk is removed from each corner on the top-plate with just a good old plain handsaw and Hey Presto .. All will Comes Together Plain and Simple .. Nice and Strong .. Oh Phew .. Smile!
On Saturday, we can proceed with a much relieved state of mind over these LVL Hip Rafters and get on with it much faster! Hooray!