The Brew Cabin

Posted: **Mon Jul 04, 2011 11:15 am**

Hello, i cant seem to find a definiative answer to my query.

i'm lifting old flags and replacing them with 300mm x 300mm pre cast slabs, at front door and porch which includes steps.

The subgrade will be the previous cemented base, cleaned up and removed of all loose matter.

Normally i would use an unbound "quarry dust" bedding mix with a tiny bit of cement sprinkled throughout (about 50:1).

My problem is that beacuse of the steps, i dont want any loose or any chane of "kicking" the small flags if walking up the steps.

So what mix should i use? i'm planning to screed bed.

thanks

Posted: **Mon Jul 04, 2011 11:43 am**

I think you need to change your plans.

1. Screed bed is no good for this job. The slabs need to be laid on a full bed of mortar

2. Mix should be 4 parts sharp and 1 part cement, little bit on the wet side.

3. Would not do any harm to throw a bit of SBR in the mix to aid adhesion

Steve

Posted: **Mon Jul 04, 2011 11:50 am**

London Stone Paving wrote:I think you need to change your plans.

1. Screed bed is no good for this job. The slabs need to be laid on a full bed of mortar

2. Mix should be 4 parts sharp and 1 part cement, little bit on the wet side.

3. Would not do any harm to throw a bit of SBR in the mix to aid adhesion

Steve

Thanks mate, i thought it wasnt the right way.

Would you recommend slopping a very wet brush to the underside of each paver for more adhesion?

Would there be a danger of efflourescence if doing so?

Posted: **Mon Jul 04, 2011 6:06 pm**

If you really want to make sure they stick add some SBR to the mix as previously stated and also paint a bit of sbr / cement slurry onto the backs of the slabs.

sticks like the proverbial s**t

Posted: **Mon Jul 04, 2011 9:44 pm**

personally i dont like 300 by 300 units on steps
by the time you have 40mm overhang theres not a lot left
on the steps especially you need to prime them with SBR/cement and put it in the mix
dont get it on your hands as it sticks to anything
LLL

The Brew Cabin

Bedding for small flags