UKC

just for a garden path, no heavy loads, about a dozen of them i think - do i need to do a mortar bed (wet cement and sand mix) or can I get away with just sharp sand?

hoping for easier option but will do the wet mortar mix if relying in sand will cause movement and wobbly slabs in a few years time. I suppose even if just using sand I'll need to compact right down so mixing up a mortar may be better.

cheers for any pointers!

In reply to d508934:
You can use sharp sand on a bed of compacted limestone hardcore. You will need about 100 - 150 mm of hardcore bed and 25-50 mm sharp sand on top. If you have a generally stable base this will be adequate for a garden footpath for many years. However if you have ants and or growing trees nearby it is likely you will get movement over time and current best practice is to lay on a bed of wet concrete.

Do not even think about what is called spot bedding. This is basically four or five dabs of mortar or concrete under each slab. This is useless and will certainly lead to uneven slabs and rocking very quickly.

Pavingexpert.com. Is an excellent advice site for all manner of related stuff

In reply to Arcturus:

thanks for web link, really useful. looking more like I'll do it properly with compacted hardcore etc - but was thinking about more of a stepping stones layout with grass in between, can't see any other way of doing that than just using sand, unless I can lay turf in between the slabs once laid.

In reply to d508934:

If you've only got a few to do then a manual ground compactor is useful for whacking some hard core down (and then limestone over the top). It's hard work (= good training) and you can work at your own pace rather than hiring expensive (and unreliable) vibrating plate compactors.

In reply to d508934:

This is weird. I've just come in from the garden where I had been investigating an identical problem and I was about to google "laying paving slabs". The UKC page was open and the first thing I saw was your post!

I have lifted a couple of mine and they seem to have been spot bedded so I shall probably relay them from scratch.

In reply to d508934:

Dig out turf to depth of slab, place slab, go climbing.

In reply to althesin:


I lived in a house with a two storey extension built like that!

In reply to mypyrex:

small world eh! can recommend the site above, pavingexpert.com, have just spent an hour on it, loads of detail. bit confused overall now though, i think for general garden path i should use a cement/sand mix but no idea if it needs compacting, layer of sand on top etc. perhaps too much detail on that site, needs a few more hours to work it all out!

In reply to d508934:

I can't see stepping stones needing anything underneath if you're just having individual stones level with the top of the turf. It's not like they're going to have heavy traffic over them or they need to all be level with each other.

In reply to d508934:
Me and my wife laid slabs at the front of the house two years ago, and used a dry mix from B and Q. This stuff apparently absorbs moisture and sets in its own time, but unfortunately I can't remember what it's called! It looks like wet sand when laid (despite being called a dry mix. I think it because you don't actually add any water), and because it doesn't set quickly, it gives you plenty of time to work the slabs. We laid the stuff about 50mm deep on a bed of small stones (chuckies) and took our time ensuring the slabs were level. We didn't walk on them for a day, and two years later they are still level and firm. Don't know if that will help at all.

In reply to pamph:

Slabcrete from Wickes worked well and sounds similar. Dig out, judge angle and position add slabcrete, damp down apply slab, tamp down. I wasn't able to go climbing after laying a path of paving slabs. It was hard work! You end up moving them around a lot and they are heavy!

In reply to pamph:

sounds ideal! did you have to compact it down at all? the chuckies and the mix that is.

In reply to d508934:

I've just done similar in my garden. A layer of builders sand on top of hardcore.

Do have to fill in the gaps for a well or two as it settles but I've had no movement since.

In reply to d508934:

We have a few sleeper-effect paving slabs in the garden laid by landscape gardener.

I recently had to pull one up to make room for a base for daughter's play house and was surprised to find it laid on a base of a load of rubble, comprising odds and ends of brick and tiles of various sizes and some cement to hold it together and stop movement.

When I chipped it off the slab, I had enough to fill a big plastic recycling crate.

In reply to d508934:

No we didn't have to compact the base. It was originally chuckies laid straight onto the soil, so we simply laid the dry mix on top of that. The chuckies were about 25mm deep, but we put the dry mix on top of them without any extra work! Perhaps we have been lucky, but the slabs are well stabilised now, so it worked well for us. But to reiterate, we did make sure that the slabs were well bedded and level on the dry mix. It took us a day to lay two areas about one metre by four each.

In reply to pamph:

great, thanks!