Timber frames

Having sensibly given up on railway sleepers, a timber support frame work of some description was required. What type of frame design was still an open question. Heck I could not have told you any of the possible designs at this stage. However, what ever the design it was going to have to be robust enough to take the weight. I needed some tables to tell me what size of timbers to use. The internet was great for this. A quick search revealed loads of links.

Diy Doctor

dprhardwood

Tember Decks

I decided on 8" by 2" joists 16" apart. You can support decking timber perfectly safely with wider joist spacing, and it fact I had a manhole to worry about, where I would need to allow wider access (and it was just as well I did!). But I was planning on starting the easy end away from the "L" shape and the manhole. I figured by the time I had built 10m or so of frame work. I would have learnt a bit and have a better idea of what to do. With 16" joist spacing then the decking board would feel totally solid under foot, with wider spacing of up to 24" you are still safe, but there will be a bit of flex.

On one end the joists would be supported on joist hangers set into some 8" by 2" ledger plates attached to the wall with frame anchors.

On the other end, well I had decided on 4" by 4" posts, but how they would attach to the joists was still a matter of some confusion. Might the posts be very long for example to provide a frame work not just below, but also about to support whatever fencing I put round the deck? I had no vision of what the fencing might be, but there would have to be some, leaving a 5-6 foot drop just is not socially acceptable!

So I kept on searching the net until the answer leapt out at me. The design would be cantilevered. In this model the support posts are sandwiched between two planks and the joists lie across the planks, where they are basically held in place merely by weight alone. The cantilever can be up to 25% of the joist length.

The advantages of the cantilever frame are many fold.

1. The support posts can be shorter as they will be further up the hill. In my case it rendered the longest posts still well short of the point where diagonal cross bracing would be required.
2. You don't need to worry about making the tops of the post level with each other. The 8" by 2" planks sandwiching the posts will of course need to be level, but being an inch or two out on the posts, won't matter so long as they are not above the required level.
3. There are no joints to cut, joints only present more edges that will need treating, and weaken the wood.

This is as far as I went with the design at this stage. I felt confident that this was the way to go. Handling the "L" and the fencing would work itself out in time. But I still had not finalized the dimensions.

Whilst I was feeling pretty confident, I can't say my friends all had such boundless optimism. My good friend from Yorkshire Barry, even bought me a book on timber decking, reflecting not I think spontaneous generosity, but more a concern at the potentially brewing disaster.