Advanced Roofing - Wrap up

Today was the last day of TAFE fot this course. All i have now is to finish my time as an apprentice and get signed of on all the on site requirements before I get my trade so that's pretty exciting. The past few weeks of advanced roofing have been really valuable, my knowledge of the theoretical side of roofing has increased 10 fold and I feel pretty comfortable that I could tackle an oblique roof, develop the bevels and set it out with out to much difficulty. We've wrapped up the last two days of the course with a hexagon end roof and it finished up looking pretty schmick. I'm pretty stoked with myself in terms of how far i have advanced with my math, I remember the first few weeks of TAFE I wasn't excited to realise that this course involved a bit of math (I was a little bit nervous as it is the one subject I've always been pretty average on) but now I breeze through my calculations without much trouble at all. All in all, I've had a great time here, I've not only learnt heaps but also enjoyed my learning experience. Of course that's only possible with good teaching and good fellow apprentices so cheers to Paul and the other boys and whoever else was involved in TTT.

Truncated Hip

Our next project was the truncated hip. Using the roof we had already built for the dorma window, we installed a new plate cutting of the corner of the hip. We then went back to the got the workbook and calculators out figured out our cuts and measurements following the instructions on the work book. Rhys and myself had a little bit of trouble trying to work out the edge cut for the basted hips but then realised it would be half the edge cut for the creeper rafters on the normal roof for that pitch as the new hip is bisecting that angle again. It was an excellent little project that highlighted the skills we've obtained over the last few weeks in the advanced roofing.

Dorma windows

The last couple of days we've been we've been constructing a dorma window. We started by putting some ridge on a high shelf and using that as a hip end. We then laid plates on the floor accordingly, backworking to get the correct span based on the set height of the ridge on the shelf, and filled it in as usual but using a 45degree pitch and not fixing in a jack but leaving a 900mm space in the center as seen in the diagram created by Robert Spencer.

The next step was to decide on the details of the Dorma, particularly the height making sure it wouldn't be higher than the main pitch and the size of the window (in courses) keeping in mind the purpose of the window is to let in light. With all the details decided we framed it out and pitched the roof. It was a great little exercise and I learnt a few interesting things in the process including that the angle of the valley boards that meet on the ridge is the same as the purlin edge cut and the angle of the vb's on the jack is the creeper side cut.

Oblique Roofs

Another great week at TAFE last week. Our focus was oblique roofs which I first thought was going to be a bit tough but after the first day I realised it's not a whole lot different to a normal roof. In brief these are the steps we followed to set out the oblique end. First, calculate the length of the oblique end. Next we work out the positioning of the centering rafters (Lets call the half span A, Long side B, short side C and oblique end D), this can be done by adding (B + D) -C divided by 2) we call this run B or C. Use this run to measure back each way from the corner and you have the position of your Jack and centering rafters. To calculate the Ridge is B-A-runB. This is how to set out the oblique end