Decking - lay frame on concrete, patio slabs or ????

[Greystoke]

Hello all,

I've been looking at a number of websites and books on laying decking, and it's left me very confused :=AC(

I'm looking to build a 12'x14' deck at the rear of my garden. The ground has been cleared and is currently just a soil patch between the victorian dividing garden walls. The question is, what should I lay the frame on?

I've read a number of articles that say placing the frame on a number of strategically placed patio slabs will suffice; others that say I need to bore a number of holes and make some concrete pillars !! Obviously the first options sounds far more appealing, but will it work properly??

Any help much appreciated.

[.]

2 adults, gentle use, method one.

large family, frequent use, bbq's etc, method 2 but concrete pillars is probably going OTT, breeze block plinths would suffice.

[Greystoke]

Thanks for the quick reply. The use will sort of be in-between the two; mainly two adults, but regular bbqs etc in the summer.

The breeze block plinths sound interesting - are they a thing in their own right, or are you suggesting laying the frame on a number of breeze blocks rather than the patio slabs?

Cheers.

[.]

the breeze blocks take the place of the slabs.

imagine this from the erlund house on grand designs

with standard thermalite/heavy blocks blocks a lot closer to the ground (depending on the height you want the decking, obviously). if you want to avoid fixing into the adjoining walls you can also locate the joists into the blockwork to prevent lateral movement. I'd attempt some asci art but it's late and I can't be bothered, sorry, I'm sure you know what I mean and can adapt the erlund example :-)

[The Medway Handyman]

Can you fix to the walls? If so, one or more sides could be supported that way.

If you can't fix anything to the walls, then build a square 12 x 14 frame from 6x2 timber. Lay this in position, make sure it's square. Mark the ground on each corner.

Dig a hole in each corner about 18" deep and fix 4 x 4 posts in the holes with concrete.

Fix the frame to these, get it level & trim the posts flush.

These things are superb for fixing decking joists & timber.

in with 6x2 joists at 16-18" spacing. Now get a FB to wander about on the joists. Where it bounces lay a slab on the ground, level it & fix a piece of timber to the joist to give support.

A 6x2 will span about 10' without too much bounce, above that it needs some support.

[Greystoke]

Thanks for the info guys !!

I think I'll go for a mixed approach: attach ledgers to each of the walls and use blocks to support the frame inbetween. Hopefully this should do the job.

[.]

the main reason I advised the use of blocks was that they are cheaper and easier to work with than slabs and less likely to crack when under the load of a beam running down the centre of it. either way, I'm sure that the eventual method you choose will suffice if not be over engineered !

oh, and if you do decide to fix into the walls (bad idea imo) do make sure you have permission to fix into the wall/s that isn't are not yours.

[Vass]

I second this after taking your advice and buying these - pretty expensive - but very VERY strong and do the job just fine Hope to finish mine this weekend :-) (weather permitting)

[Vass]

See below reply to my similar query 31st July.....

"I built my deck a couple of months ago. about 3.6 x 5.4m (3.6m cos of timber length of course, although it did also happen to fit). I did not dig holes for the posts. Everything is fine and solid as the weight of the deck holds everything down, BUT if I was doing it again I definitely would concrete in at least the main corner posts. I found that not doing this caused everything to move out of square every so often, with all the hammering and general bashing about. The middle posts can just sit on a block or a couple of bricks. In fact in a few places I just stacked up old bricks with a slate top bit. By the way, I bought a big pack of coach bolts from screwfix and they were great for screwing joists together and for holding warped joists in position once the warp had been corrected. Hope you get good weather! Alistair "

[Christian McArdle]

Personally, I would do it the way I did for my conservatory base. I dug cubes of earth 450x450x450 with a spade and laid breeze blocks on their sides. 8 per hole, jointed with mortar, with a small amount of wet concrete poured underneath and down the sides to backfill.

For decking, I would probably use smaller holes, i.e. only 4 breeze blocks in two layers, digging about 220mm deep.

Christian.

[Tony Bryer]

I've got as far as the concrete stumps. I used a post hole borer from a hire shop which creates neat holes that don't use a lot of concrete. With the holes bored I first put in a bit of dry mix and rammed it firmly into the base of the hole, before filling the rest - cutting the bottom off an old bucket made a suitable funnel to get the concrete in without also adding lots of soil.

[Greystoke]

Wow, lots of choices !!

As I'm a bit of a novice at all this (but very ethusuastic) I need some guidance to do the job - anyone know of some good links etc... to help me out?

Cheers.

[.]

select a method and GTF on with it. once started jobs usually write themselves. don't start a job until all materials are onsite.

the last several posts ought to be enough to get you going.

[Mathew Newton]

And if you're after a recommendation for the screwing the deckboards down I'd suggest these:

do exactly what they say on the tin and worth every penny. Even after 400 of the little buggers I was still smiling. Okay, maybe a slight grimace but that was more from backache...

Well, since we're getting our slides out... ;-)

[Vass]

very nice job well done!

[Mathew Newton]

Don't tempt me... ;-)

...or her for that matter - I've lost count of the number of times I've had to pull recently-fitted floorboards up to let the bugger out. I once toyed with the idea of getting her to pull a piece of string under the floorboards from one end of the room to the other in order to facilitate subsequent cable routing however I think she sussed what I was up to and promptly buggered off.