Raised slabbing - any experiences ?

[Jethro_uk]

Following the idea of raising my patio with decking, I stumbled across the possibility of using slabs set on adjustable supports ...

support-pads/

has anyone tried this ?

[meow2222]

thougt it said raised stabbing, and was perhaps a request for medical assistance following another apprentice disagreement :)

Surely there are cheaper & more stable options than those products

NT

[Tim Watts]

I wrote a thread last year praising these. I used s few to sort out a shed that was on a base that has a 3" slope corner to corner.

I used a few more than I needed as I put then at every joist intersection with the main runner. If I'd built the shed myself, I would have been more confident in the base and used 1/2 the number.

But yes, they are very good, not too expensive as I used them - but as you need one for each slab roughly the cost might add up.

The only concern I would have is whether the slab in question is strong enough as cheap thin slabs assume they will be evenly supported by a bed. I have full confidence in the stands, and less in the supported material.

But it would be easy enough to test by propping a slab on 4 bricks and jumping up and down on it.

[Jethro_uk]

I'd rather use smaller slabs and more corners.

Grey-70-Pack/p/224596

Yes, it may need a lot, but rough back of the envelope calculations suggest cheaper than decking by a long shot (decent joists aren't cheap). Also it should require the minimum of work to fit, since the patio is

*already* slabbed. Fitting the decking would have involved cutting joists and decking to length with the added complication that it would need to be laid diagonally, since there would be 2 main directions of traffic.

The biggest advantage for me, is that it's a temporary installation which can be removed *when* we sell the bungalow. Anything more permanent could prove a nuisance when we sell.

[Jethro_uk]

If there are, I hope someone will suggest them ;)

[Tim Watts]

They're very stable IME.

This is absolutely no different to laying computer room floors which have adjustable legs at each tile corner - though those are usually metal legs.

And computer room floors carry vast loads like 10's of tons (and very high point loads in places).

The only reason you don't see builders using them is roughly the same as you never see builders using SBR admixes, resin products and other "new" inventions, because, well, they're new...

[Jethro_uk]

I have no intention of letting a "builder" anywhere near this job, so it has to be DIY.

One thing I've noticed is the longer the adjustable supports, the more expensive they are. I wonder if I could use something like breeze block to reduce the 230 mm drop ?

[Nightjar]

Presumably, if it breaks, A&E will record that as a falling accident.

[JimK]

seems to me these are going to rely totally on the strength and enduring "levelness" of what is under them - which is what? or going to be what?

Jim K

[Tim Watts]

Jolly good.

No reason why not - as long as the block is strong enough for the compressive loads - but the loads are not high and the feet have quite large area bases.

[Jethro_uk]

It's already slabbed onto compacted hardcore. It's a patio, and will only carry foot (well wheelchair) traffic. Nothing over 100Kg.

[meow2222]

Adding timber stubs to the joists would seem the obvious option. Then there are blocks etc.

NT

[The Medway Handyman]

£60 per sq mtr installed for decking.

[dennis]

You need to go to your local carpet shop and get some tubes out the rolls. Dig a hole with a post hole digger put some concrete in the bottom Cut a length of tube to about the right hight when in hole fill with concrete. put slabs onto with mortar to level.

[meow2222]

whatever for!

NT

[Jethro_uk]

so 18m2 x 60 = c. £1,110 ?

Twice the price of slabbing (so far)

[GMM]

I'd have thought using the blocks mentioned previously would distribute the point loads quite a lot too. And from the movie, you can always lift and re-level if needed.