Bad workmanship?

[graz]

I'm having a block paving drive laid, the main part of the drive has been laid on a very hard sub base which is quite impermeable. It is also on a slope so all the contractor has done is put 2" of grit sand on top of the sub base and laid the tegula block on quite a rainy day.
He has not been able to put the kiln sand on top and whacker plate as we have not had good enough weather. Since he laid them it has rained even more and the grit sand is coming up between the blocks
My concerns/questions are how will the contractor be able to fill in the gaps between the blocks with kiln dried sand especially as they have already started to sink and also once the kiln sand has been done and the water has nowhere to run apart from under the blocks, will this eventually wash the grit and kiln sand away and make the blocks unstable or as the contractor has told us the kiln sand will "seal" the blocks so the water will run over the top.
Any suggestions ?

[lutonlagerlout]

if the blocks are sinking they may have to come up and be relaid
a picture speaks a thousand words so if you could post a piccy we will have a look and give our opinions
cheers LLL

[graz]

Thanx for your response LLL.
I took some pictures but they don't really show the sunken block, anyway the contractor is putting it right (he said there was a stone underneath!).
I got in touch with marshalls as the contractor was recomended by there website and asked them a few questions and and they reasured me he wasn't doing anything dastardly as long as he puts it all right. We are just waiting for a few days of dry weather so he can put the kiln sand in the joints. He talked about making a slurry with the sand and washing it in the joints.

Have you heard of this method?

[Mark B]

ive not heard of the slurry method :S , the whole point of brushing in kiln dried sand is that it is that (kiln dried), why pay for kiln dried sand just to wet it before its brushed in. the sand has to be brushed in when totaly dry so that it will go throughout all the joins locking the paving together once finally compacted.

[Stuarty]

That part sounds dastardly to me. Marks right, it must be dry.

[salvador]

I had a driveway laid in August 2006 and I am still having problem with sand washing out of the joints of the clay blocks. It is on a slope and I am forever brushing the sand away from the base of the slope. Is there anyway that I can reduce this problem or is it here to stay? Also I am not happy with the drainage of the drive which has now started flooding my garage. Who can I contact for a free expert opinion on whether the drive was laid correctly to start with? Would the council Building control officer help?

[lutonlagerlout]

Would the council Building control officer help?

no mate
you need to contact the people who laid it first to see if they will remedy it
it doesnt sound right if water is running into your garage,can you post us a picture??
cheers LLL

[Stuarty]

You can seal the driveway, but i have no experience with these products so hopefully someone else could elaborate on this

The problem of drainage; If the fall is towards the garage, and the linear drain, im assuming there is one, isnt coping, it could just be blocked with sand and dirt.

If the fall isnt toward the garage, or wasnt intended to be it could have been a fault on the installers part. It all depends what the job specification said imo.

Im not sure if the building control officer will help - i dont have to deal with those folks heh

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Typical, i spend so long typing LLL gets to it before me heh

[Dave_L]

Free help/advice after someone's done a bum job? I think you'll struggle to find it!

[lutonlagerlout]

Typical, i spend so long typing LLL gets to it before me heh

"he who dares wins rodney" D.B.Trotter 1987
LLL

[seanandruby]

you seem to have gone from sunken blocks to a single block? it would be reasonable to assume it was a stone. but the "slurry" is a definate no no.

[Nigel Walker]

The slurry technique is used all over europe. In fact Probst manufacture a sanding machine that uses water added to the sand

I have tried it a couple of times. In extreme wet weather, at least you are guaranteed that the sand goes in the joints. Eventually the sanded joints will dry and then you top up.

Its not a method I like using, but in our weather sometimes its necessary.

Nigel

[lutonlagerlout]

have you seen the state of the block paving in holland nigel??
for the life of me unless you have a 5 mm joint i cant see how slurry will penetrate
???
LLL

[Nigel Walker]

Why ?

Is there some chemical reaction that makes the sand grow in size when water is added. If the sand goes in the joint when dry, why not when wet ?

It does work, its just that we are not used to the technique in this country.

Dont forget where Flexible Block Paving originated . oh yes Holland and Germany ! And believe me, they are much more advanced than we are

[Ross-Paving]

I agree with the slurry route - If you haven't tried it then comment after you have!
I find it hard to believe that some people only work when the sun shines.