Thanks for all the replies. I think I am going to go with the 2 frame solution. Nothing personal Thermo I just think the costs will be cheaper and it will mean less drilling. Time and money are concerns here.
I'll have 3 6x2 beams running the width (parallel to the house wall) of the area and will add some noggins to keep it rigid. This will fixed at approx 1m centres. I can't fix this part of the frame to the house wall as it will block the air bricks. It will have to just sit on the patio.
Then I will rest the frame (made from 5x2) on top of this. The frame will be fixed to the house wall only (with 10mm shims) and fixed to the frame underneath.
Then the decking boards will be screwed on top.
A few more queries though (sorry).....
- How much should the spacings be between the joists in the upper frame? I have read 1.8m, 0.75m and 0.4m. Apparently this may depend on the length of the decking boards. Well, I hope to use 1 board only to span the width (approx 4m).
- I hope to use ribbed decking boards and am a bit concerned about 'run off'. The decking boards will run parallel with the house wall and so in theory should have a gradient to allow the 'run off'. Now, with a 4m length and a 1 in 100 gradient the left side of the deck will be about 4cm lower the the right. This will surely look weird? I don't really want to change the direction of the decking as this will mean more short pieces, more cutting and I personally think it looks nicer running parallel with the house. Is this 'run off' thing necessary?
- Do the joists need to be stress graded?
- What is the best type of saw to hire for cutting the beams/joists/boards?
Cheers all - gaining confidence all the time!
I'll have 3 6x2 beams running the width (parallel to the house wall) of the area and will add some noggins to keep it rigid. This will fixed at approx 1m centres. I can't fix this part of the frame to the house wall as it will block the air bricks. It will have to just sit on the patio.
Then I will rest the frame (made from 5x2) on top of this. The frame will be fixed to the house wall only (with 10mm shims) and fixed to the frame underneath.
Then the decking boards will be screwed on top.
A few more queries though (sorry).....
- How much should the spacings be between the joists in the upper frame? I have read 1.8m, 0.75m and 0.4m. Apparently this may depend on the length of the decking boards. Well, I hope to use 1 board only to span the width (approx 4m).
- I hope to use ribbed decking boards and am a bit concerned about 'run off'. The decking boards will run parallel with the house wall and so in theory should have a gradient to allow the 'run off'. Now, with a 4m length and a 1 in 100 gradient the left side of the deck will be about 4cm lower the the right. This will surely look weird? I don't really want to change the direction of the decking as this will mean more short pieces, more cutting and I personally think it looks nicer running parallel with the house. Is this 'run off' thing necessary?
- Do the joists need to be stress graded?
- What is the best type of saw to hire for cutting the beams/joists/boards?
Cheers all - gaining confidence all the time!