This is almost certainly one of those questions where the answer depends on details I can't yet provide, but anyway...
I want to lay a patio some eight feet deep using (or rather re-using) 400 x
400 x 28mm slabs. At a later date, I want to erect a two-foot high wall, probably of single-skin brick, along part of the long edge of the patio.How feasible would it be to build the wall actually onto the patio itself? That's to say not digging out and laying any separate foundation?
Many thanks.
It wouldn't, it would need a foundation of some sort or the weight would cause it to sink.
Of course that could be under the offending slabs.
Thanks for the replies, and for confirming my suspicions. So the sensible thing to do would be to lay the foundation for the wall at the same time as creating the patio, even though the wall would be a later addition)?
I've just done a similar (8ft x 8ft) thing, but I thought the bricks would have looked odd stuck on the slabs. No big deal to dig out a small trench alongside the patio. I had a bit of hardcore to get rid of anyway.
Yes. And the single skin wall might need supports at the ends.
Zero feasibility.
That does seem to be the way to go, so thanks for the confirmation. Did you extend the trench actually under the patio's edge, so as to have a foundation wide than the wall?
Succinctly put. Thank you.
I was assuming so, and perhaps elsewhere along its length as well.
I'd go down about a foot, build the wall with metal ties to make sure it didnt split and then lay the slabs later.
yes. OR use stuff like rebar IN the wall. Remember a atrip foundation is simply to stop local stresses cracking the wall or it rising or sinking.
If all you care about is not cracking, reinforce the wall with steel.
If you do a simple stretcher bond double wall capped wit a soldier course there's room to use steel between the courses and in vertical and horizontal directions, and some ties will hold the courses together as well.
Thanks. It's sound advice but unfortunately, for reasons far too boring to go into, the patio has to come first.
Steel in a wall introduces a likely failure mode. Rope in each course is good enough if you wanted some reinforcement. With a 2' high wall I certainly wouldnt use this as an excuse to skimp on the footings - thats only practical for tiny walls.
NT
Yup. You won't need a huge foundation for a 2' wall. If you know where its going to be when doing the patio, stick in a 8" - 12" deep concrete haunch along that side, and bed those slabs on mortar even if the rest are laid on dry mix or just sharp sand.
I think you had better tell that to the shard and onion people
They will be very interested to know that.
No. I regarded the patio base as sufficient on that side, and there's probably a brick width on the other side. What the hell, it's only a small retaining wall, and I'd rather grow things than fill the space with footings. If it fails, I'll stick it all back together :-)
In advance of a daughter's wedding, I did some hurried patio laying on dry mix over compacted type 1 with a dwarf wall (2 stretchers + soldier course) to retain a raised border.
Rather than cut each slab to suit the curves of the border, I laid the wall on top of the slabs. However, before bringing the soil back to the wall, I buttressed the wall from below slab level and up to the soldiers with a stiff mix concrete. Still looks fine.
re-using)
two-foot
I can't see a 2' high single skin wall laid down the center line of
400 mm sq well bedded slabs sinking into the ground. Probably a better footing than a narroe small trench and a few inches of concrete, the load will be spread for a start.TBH I'm more worried about the later mentions of "retaining wall". Single skin 2' high and 8' long high will almost blow over. B-) It'll need some vertical reinforcing of some sort.
Erm, would not the weight just tip the paving up and dump the wall outwards, especially if anyone tried to sit on it? Brian
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.