The Brew Cabin

Posted: **Tue Jul 17, 2007 9:05 am**

Hi,

I have just started laying pre-cast concrete riven slabs for a patio.

I am using a 35-50mm 10-1 dry mix - each bed being individually made for each slab as the thickness is variable. Each slab being consolidated with a mallet. I pointed the slabs in within 3-4 hours of being laid. A few days later I notice that a couple of slabs are slightly loose - just enough to crack the pointing around the joint with the slab.

I'm obviously doing something wrong - any ideas or advice would be appreciated to prevent remainder of patio suffering a similar fault and to correct the current slabs.

Thanks in advance,

Stew

Posted: **Tue Jul 17, 2007 9:03 pm**

if you are using a dry mix you dont want anyone walking on the corners ,for a good while
i always try and use a scaffold board to spread the load but this works best on smooth slabs
sounds like someone has been on them before they have gone off
LLL

Posted: **Tue Jul 17, 2007 10:07 pm**

Thanks for the reply. How long does the dry mix take to go off? thanks again Stew

Posted: **Tue Jul 17, 2007 11:24 pm**

when the lads here call it a dry mix in fact its not dry at all its slightly moist,i dont use it but i have been told a day or 2
cheers LLL

Posted: **Wed Jul 18, 2007 7:05 am**

Cheers, thanks for that, what do you use then?

Stew

Posted: **Wed Jul 18, 2007 10:27 pm**

I use a wetmix,as a bricklayer by trade i find it easier to get on with and its gone off a lot quicker
cheers LLL

Posted: **Thu Jul 19, 2007 8:40 am**

thanks

Stew

The Brew Cabin

New patio slabs - very slight movement