Concrete bases - Does anybody use them for paving

[cookiewales]

its all about strenght and freeze thaw soft sand degrades very quickly on freeze thaw and even more on movement am sure t mc has some views on this ps the laying on semi dry should allways be soaked with lots of water at intervals throught the day if you do that with soft sand they will sink .you have to be carefull when using mersey grit sand dreged it turns to sqeulch when wet you darent breath on em

[DNgroundworks]

Absolutely agree tony, this is the only time i have ever done it, never would do it on type 1, I know Tony mc has some views on it cookie, but i reckon its fine here, how come freeze thaw doesnt effect buildings that are built out of soft sand and cement?

Ive tried the soaking method cookie, still no luck, flags still sounded hollow, ive tried the normal 50mm thick layeing course and upto 80mm, there is zero bond and the flags are always hollow.

I normally use sharp sand, pretty wet tbh and knock the flags into it, seems ok?

[lutonlagerlout]

because buildings have dpcs dan
patios do not
LLL

[Thehandmadegarden]

because buildings have dpcs dan
patios do not
LLL

Not for the first bit out the ground they dont! Im not sure the freeze thaw argument stands up.

I use grit for bedding but I use soft when bedding flags on steps with a class II mix

The trouble with concrete base is its often used as a way of covering bad practice. ie get rid of all your crap beneath bricks concrete etc CBM is used on poor ground where MOT wouldn't be strong enough, but Id want to address the poor ground before I went that way. A problem as I see it is if water does enter by capillary action or migration from the sides its going to take longer to dissipate.

Hmm the sticky down flags debate again :-/....dont you just hate it when youre walking down the high street and all those paver's bedded on sand only are just blowing down the road!!

Clive
www.thehandmadegarden.com

[lutonlagerlout]

those pavers weigh 60kg each clive
300 by 300 injun stone unit weighs about 2 kg
LLL

[GB_Groundworks]

It's more to do with the interlock of the grain size of sharp sand as opposed to the fine grade of building sand, and technically mortar doesn't stick anything together it's held in compression by the weight of the bricks above and the roof.

You don't have that in a patio, we always use sharp sand or limestone dust with sbr added for good measure.

We just had to break some haunching up from some tegula kerbs and it was a soft sand mix stuff just fell apart no strength at all

[DNgroundworks]

Im not sayin you guys dont know what you are talking about, but 4-1 with sbr aint going to be a problem, i am unsure of the freeze thaw debate also, especially in this situation, on an MOT base then yes it has credit.

this was a one off for me btw :p

[bodgeitandscarper]

Clive, cant seem to view your pics on your website!

My old gaffer liked to use sharp sand and a bit of whatever was banging about! soil, tarmac etc!