No hardcore base for slabs?

sibersha

Hi. Not really my strongest area so forgive any ignorance shown.

Over the weekend, had 22m 600x900, 600x600 and 600x300 natural stone slabs laid covering roughly 28 m2. Job looks great however concerned about the base.

Basically he laid a rough sand and cement mix directly over grass and laid the slabs directly on top. No blinding of grass, no hardcore, no compressed soil. He assured me this would be 100% and would be sufficient support for any weight on the area and would not sink.

He showed me pictures of a number of jobs he done all using same method, including his own garden a number of years ago.

Anyone I mentioned this to seems very surprised no hardcore was laid and I now have a growing concern. So will I have sunken/collapsed area in 6 or 12 months down the line?

Thanks in advance

Dublinstiofán

If he’s that confident that there will be no subsidence tell him you will pay him in 12 - 18 months when you can see that for yourself.

goz83

:eek::eek::eek:

I'm no expert, but that sounds proper cowboy. I recently had around 20SQM of 300x600 sandstone laid. There was a thick layer of concrete already in situ, but we had to bring the yard level up by at least a foot due to a new extension, as we wanted to avoid any steps. So I used bricks as filler, then gravel to fill the gaps and THEN the hardcore, gravel and sand went down before the slabs. No concerns about subsidence here.

Yours could be fine for a while, but in a year, or two it may well start to sink depending on the soil beneath. I reckon you've already paid, so I hope you have the invoice and a guarantee.

Metric Tensor

GRASS?!!!!!

I can't see it ever being appropriate to lay any sort of surface on top of topsoil - it's full or moisture and organic matter and much more likely to deform or change in shape over time. It also tends to have poor drainage characteristics.

But laying it directly on top of grass takes the biscuit altogether!

It may last but it's definitely not the right way to do it.

my3cents

You remove all topsoil down to subsoil for that sort of work period.

You employed a cowboy.

sibersha

Thanks for replies. The OH paid him but he has to come back to collect tools so I'll quiz him then.

The soil in garden is full of stones and drains very well. Nonetheless looks completely dodgy practice based on above comments

Johnnyhpipe

That is a crap detail.

sydthebeat

Not even a geotextile membrane??

Id give those slabs 12 months and there will be greenery growing between them...

_Brian

Don’t let him take the tools until the slabs are correctly laid.

They are your last piece of leverage here. Once they’re collected this guy is gone forever you will have to pay someone again to have this corrected.

There is no way he should have laid these slabs on topsoil, they will settle/sink unevenly and you’ll have a terrible mess.

tradesman

This is definetly cowboy builder territory. As _brian said. Hold on to his tools until it is laid with a proper sub base. In fact destroy his tools! A builder like him should not be allowed near anything construction related!