Hi;
Bear with me this is a long one
I am building a small workshop which will consist of a timber frame mounted on 4 courses of blocks. The timber frame will be covered with OSB, a waterproof membrane, battens and cladding. On top I intend to install a fibreglass flat roof.
Here is a pic of the proposed building with dimensions.
The rear wall is 335cm and the front is 232cm.
I am making up the timber frames using 75 x 50 timber. The back wall is a block wall that is already in place and my rear wall plate supporting the roof joists will sit on top of this. To join the front frames and to add a header above the door I will also run a wall plate along the top of the front two frames.
The height from the top of the new block walls that the timber frame sits on to the top of the rear block wall is 146cm so I was going to build my frames using king studs of 146cm so that they sit flush with the top of the wall. Owing to the thickness of the wall plate there will be a gap of 50mm (the thickness of the wall plate) between the top of the left and right side frames and the roof joists and also between the roof joist along the front. This gap can be covered when I cover the frame with OSB.
To give the flat roof a drop could I raise the height of the king studs in my frame to 150cm? This means I get no wastage from my 3m lengths and if I did this and then put a 75 x 50 onto top of the front timber frames the joists at the front will be 4cm higher than at the back giving a 4cm drop from front to rear. Is this sufficient and would it mean I do not need to also add furrings.
If my calculations are correct that's a 4cm drop over 232cm = 58cm for ever 1cm of drop just under 1:60 (the regulation drop for a flat roof)
The only issue with this is that the water will run to the back of the roof but this will be sitting on top of the boundary wall (my wall) and I can't really go fitting a guttering on the neighbours side!!
I could have the run from front to rear but that means the roof encroaching over the front of the shed which is built opposite my garage and may cause a loss of light?
The final option is to fit furrings on top of the roof joists but run them from right to left and have a run off on the left hand side of the shed.
If the widest width is 335cm then the furring needs to be 55mm high at its highest (335 / 6) to give a 1:60 drop. I need to work this into my calculations to ensure that the top of my roof does not exceed 2.5m.
Either way I can still make my king studs 150cm as they will still fit just below (1cm) the top of the wall plate at the rear but do I need an additional top plate running across the top of the front frames or can I just fix the roof joist to the top plates of the wall frames?
Thanks
Read more: https://www.diynot.com/diy/threads/stud-and-roof-joist-spacing.488038/#ixzz4rM0xVHmZ
Bear with me this is a long one
I am building a small workshop which will consist of a timber frame mounted on 4 courses of blocks. The timber frame will be covered with OSB, a waterproof membrane, battens and cladding. On top I intend to install a fibreglass flat roof.
Here is a pic of the proposed building with dimensions.
The rear wall is 335cm and the front is 232cm.
I am making up the timber frames using 75 x 50 timber. The back wall is a block wall that is already in place and my rear wall plate supporting the roof joists will sit on top of this. To join the front frames and to add a header above the door I will also run a wall plate along the top of the front two frames.
The height from the top of the new block walls that the timber frame sits on to the top of the rear block wall is 146cm so I was going to build my frames using king studs of 146cm so that they sit flush with the top of the wall. Owing to the thickness of the wall plate there will be a gap of 50mm (the thickness of the wall plate) between the top of the left and right side frames and the roof joists and also between the roof joist along the front. This gap can be covered when I cover the frame with OSB.
To give the flat roof a drop could I raise the height of the king studs in my frame to 150cm? This means I get no wastage from my 3m lengths and if I did this and then put a 75 x 50 onto top of the front timber frames the joists at the front will be 4cm higher than at the back giving a 4cm drop from front to rear. Is this sufficient and would it mean I do not need to also add furrings.
If my calculations are correct that's a 4cm drop over 232cm = 58cm for ever 1cm of drop just under 1:60 (the regulation drop for a flat roof)
The only issue with this is that the water will run to the back of the roof but this will be sitting on top of the boundary wall (my wall) and I can't really go fitting a guttering on the neighbours side!!
I could have the run from front to rear but that means the roof encroaching over the front of the shed which is built opposite my garage and may cause a loss of light?
The final option is to fit furrings on top of the roof joists but run them from right to left and have a run off on the left hand side of the shed.
If the widest width is 335cm then the furring needs to be 55mm high at its highest (335 / 6) to give a 1:60 drop. I need to work this into my calculations to ensure that the top of my roof does not exceed 2.5m.
Either way I can still make my king studs 150cm as they will still fit just below (1cm) the top of the wall plate at the rear but do I need an additional top plate running across the top of the front frames or can I just fix the roof joist to the top plates of the wall frames?
Thanks
Read more: https://www.diynot.com/diy/threads/stud-and-roof-joist-spacing.488038/#ixzz4rM0xVHmZ
