Decking base?

[bobnotthe builder]

I want to construct a 3.5m X 3.5m deck at the back of my house. The garden is approx 3.8m wide so this will more or less span it. I don't want to interfere with the dpc so I've thought of keeping the deck a centimetre or so away from the wall - can the wall of the house still be damaged by splashing?

Next bit.....it's difficult to access the sides of a deck this size in the space available so I've decided to build two rectangular frames with joists and then lift them into place and bolt them together - don't worry I've worked out the weight and me and my mate can lift em! - anyone foresee any problems so far? We'll put the boards down onto this frame when it's in place.

Now the tricky bit..... If it's possible to build a deck onto a patio isn't it ok just to lay a heavy concrete paving slab (got loads of these courtesy of the last owner) at the points where the beams need to be supported - about every 1.5m for 6X2s?.Would I need to concrete under the slab or would a layer of gravel (on clay) be enough. I'll go down the whole posts-in-concrete route if necessary but just wondered if this way would be ok. Also, would I need to bolt this deck down or would the weight of it hold it in place? - it's not as if there's a slope for it to slip down.

Thanks!

 

[morrik27]

I'm fairly new to this myself, and am learning alot on a very steep curve!

One bit of advice i would say is about bolting two frames together. I found when i put the joists to the posts (which i did with notched joints rather than straight to the side, so how i found out....) Make sure the two bits are VERY tight against each other, and that you go through both in one go with a decent sharp drill bit.

I nearly had a nasty accident after i found the waste from the hole was building up between the two bits of wood and forcing them apart, it ment it was harder to drill and the holes would probably ended up out of alightment.

Oh, and dont even think you can put a hole in one bit, then the other bit and they'll line up - this i learned the hard way!

 

[pitbull]

Put weed control fabric under and then gravel.As for the laying of decking on slabs just do it, it's a good enough job.Decking aint rocket science and it sounds like you have some idea of what your doing so if you are happy with it thats all that counts.Good luck with the project and show some pics when it's finished.

 

[WabbitPoo]

Quite agree - a big frame will not need "holding down" because of the large mass, but I'd recommend a few concreted in posts to keep the frame from being tempted to skew under load. Just my 2p