I am going to be replacing my garage roof. The garage is about 6.7m long by about 3.4m wide.
Im totally removing the old roof because it is broken, sagging and leaks and replacing it with a brand new felt one.
I would ideally like it to be a 4-6 inch drop over the length but I would like a bit of advice of how to go about it. These are the ways im thinking of below. Please comment on these methods or let me know the correct method.
1. put a 6 inch drop over the length:
Place 4x2’ all the way down the length and sides of the garage ontop of the brick work with the 2’ facing up. This will give the joists something to sit on and nail into.
Put 6x2’ joists across the length (will these be strong enough?).
Place 6-0 fairing pieces ontop of the joists (will give a 6’ slope)
Place ¾ inch ply (or maybe OSB board) ontop.
Place 2x2’ risers ontop at the front and sides.
2 layers of torch on felt
1 layer of mineral felt
The problems I have is that the whole roof at the front will be about 17’ high from the brick work. The biggest facia I can get is a 12’ so I would have to use 2.
Would 6x2’ joists be strong enough to hold the roof over a span of 6.7m? I cant really put a supporting joist or any steel across the width because there is a big window along the length of the garage and it is only 1 brick thick. If I did put one in the it would only be sitting on one skin of brickwork and I would have to brick up round it, or put in 2 either side of the window.
Would a 3 or 4’ drop be ok?
Would I have to put 7x2’ joists on?
2. put a 6 inch drop over the length: (method 2)
Place 4x2’ all the way down the length and sides of the garage ontop of the brick work with the 2’ facing up. This will give the joists something to sit on and nail into.
Put 5x2’ joists across the width.
Put 6’ fairing pieces across the length so that the feathers go the opposite way to the joists. Then do as above with boarding and felting.
Will this cause a problem with having the fairing going the opposite way to the joists? On the last gap at the back of the garage will it cause a weak point where the feathering will be virtually nothing? I know the fairing will only be small but it will still be sat on 5x2’ joists.
3. put a 2-4’ drop over the width.
Place 4x2’ all the way down the length and sides of the garage ontop of the brick work with the 2’ facing up. This will give the joists something to sit on and nail into.
Put 5x2’ joists across the width.
Put 2 or 4’ feairings ontop of the joists then board as above.
This will make the whole roof be about 12 – 14’ high and once again im struggling with a 12’ facia.
4. put a 6 inch drop over the length: (method 3)
Place 4x2’ all the way down the length and sides of the garage ontop of the brick work with the 2’ facing up. This will give the joists something to sit on and nail into.
Place a 6-0 fairing piece down each side of the length of the garage ontop of the 4x2’.
Place the joists across the width ontop of the fairing piece along the length. This will give me a 6’ drop over the length.
This will cause the joists to be slightly leaning but ive worked out the angle of the slope to be under 1.5 degrees so you will hardly be able to tell. If I make the slope even smaller like 4 degrees the angle and the slant on the joists will be even smaller.
6. put the joists right ontop of the brickwork. Put 4x2’ between the joists ontop of the brickwork. Secure the 4x2’ to the brickwork then nail the joists through the side into the 4x2’. With this method you also have the problem that if the brickwork isn’t level the joists wont be.
As you can see I have thought of a few ways of doing this. Please could you let me know what you think of my ways and which is the correct of best way of doing it, even if its different than the ways I have thought of.
Thanks
Im totally removing the old roof because it is broken, sagging and leaks and replacing it with a brand new felt one.
I would ideally like it to be a 4-6 inch drop over the length but I would like a bit of advice of how to go about it. These are the ways im thinking of below. Please comment on these methods or let me know the correct method.
1. put a 6 inch drop over the length:
Place 4x2’ all the way down the length and sides of the garage ontop of the brick work with the 2’ facing up. This will give the joists something to sit on and nail into.
Put 6x2’ joists across the length (will these be strong enough?).
Place 6-0 fairing pieces ontop of the joists (will give a 6’ slope)
Place ¾ inch ply (or maybe OSB board) ontop.
Place 2x2’ risers ontop at the front and sides.
2 layers of torch on felt
1 layer of mineral felt
The problems I have is that the whole roof at the front will be about 17’ high from the brick work. The biggest facia I can get is a 12’ so I would have to use 2.
Would 6x2’ joists be strong enough to hold the roof over a span of 6.7m? I cant really put a supporting joist or any steel across the width because there is a big window along the length of the garage and it is only 1 brick thick. If I did put one in the it would only be sitting on one skin of brickwork and I would have to brick up round it, or put in 2 either side of the window.
Would a 3 or 4’ drop be ok?
Would I have to put 7x2’ joists on?
2. put a 6 inch drop over the length: (method 2)
Place 4x2’ all the way down the length and sides of the garage ontop of the brick work with the 2’ facing up. This will give the joists something to sit on and nail into.
Put 5x2’ joists across the width.
Put 6’ fairing pieces across the length so that the feathers go the opposite way to the joists. Then do as above with boarding and felting.
Will this cause a problem with having the fairing going the opposite way to the joists? On the last gap at the back of the garage will it cause a weak point where the feathering will be virtually nothing? I know the fairing will only be small but it will still be sat on 5x2’ joists.
3. put a 2-4’ drop over the width.
Place 4x2’ all the way down the length and sides of the garage ontop of the brick work with the 2’ facing up. This will give the joists something to sit on and nail into.
Put 5x2’ joists across the width.
Put 2 or 4’ feairings ontop of the joists then board as above.
This will make the whole roof be about 12 – 14’ high and once again im struggling with a 12’ facia.
4. put a 6 inch drop over the length: (method 3)
Place 4x2’ all the way down the length and sides of the garage ontop of the brick work with the 2’ facing up. This will give the joists something to sit on and nail into.
Place a 6-0 fairing piece down each side of the length of the garage ontop of the 4x2’.
Place the joists across the width ontop of the fairing piece along the length. This will give me a 6’ drop over the length.
This will cause the joists to be slightly leaning but ive worked out the angle of the slope to be under 1.5 degrees so you will hardly be able to tell. If I make the slope even smaller like 4 degrees the angle and the slant on the joists will be even smaller.
6. put the joists right ontop of the brickwork. Put 4x2’ between the joists ontop of the brickwork. Secure the 4x2’ to the brickwork then nail the joists through the side into the 4x2’. With this method you also have the problem that if the brickwork isn’t level the joists wont be.
As you can see I have thought of a few ways of doing this. Please could you let me know what you think of my ways and which is the correct of best way of doing it, even if its different than the ways I have thought of.
Thanks
