I've been asked to quote for the following small job:- customers house is a former shop with a sandstone front door step which has worn unevenly over the years and they now want it tiling over with quarry tiles. The dip in the middle of the stone is about 20mm what should i use to build this up to level? should i key the sandstone with a grinder first?
Cheers
Lee.

Adhesive should be fine just check with supplier which addy to use for the sandstone..

firstly how much of a dip?The adhesive which you use might not be suitable to build up the depth,so to avoid failure i would check the depth of dip and your adhesive spec for depth.It might be worth shuttering the steps with sand and cement mix.

Originally Posted by brian c

firstly how much of a dip?The adhesive which you use might not be suitable to build up the depth,so to avoid failure i would check the depth of dip and your adhesive spec for depth.It might be worth shuttering the steps with sand and cement mix.

The depth is about 20mm - 30mm at the worst point - think the customer is worried about sand/cement mix blowing, any tips?

Could you knock off the old sandstone then slurry and a bit of screed mixed with sbr

Originally Posted by whitebeam

Could you knock off the old sandstone then slurry and a bit of screed mixed with sbr

Can't knock off the old sandstone as it forms the step and part buried, the problems is that its worn but only in the middle.

AHH, ardex do a powder which can be built up to 20mm

mapei ultraplan maxi can also be used.

Do you reckon straight onto the stone as its been worn smooth or use the grinder to roughen it up a bit?

Adesilex P4 (Mapei) can be used as a smoothing/levelling compound and can be built up to 20mm, it's the one Mapei recommend for external work

i would use grinder to ensure a good key.

Originally Posted by doug boardley

Adesilex P4 (Mapei) can be used as a smoothing/levelling compound and can be built up to 20mm, it's the one Mapei recommend for external work

Do you have any experience of using this? If its a leveller is it runny?
The doorstep leads onto a tarmac pavement and even with shuttering most slc's i've used would end up all over the pavement.

Originally Posted by redlee

Do you have any experience of using this? If its a leveller is it runny?
The doorstep leads onto a tarmac pavement and even with shuttering most slc's i've used would end up all over the pavement.

I used 4 bags today as it happens, first time I've used it and it was good to use. It is runny, so your shuttering would have to be a good one, and you'd have to work clean

That's what's putting me off slc, too runny for this one i think.
Ta
Lee.

you def need a rapid setting SLC which the mapei's are. looks like you'll have to shutter a bit ie board the front etc to stop the SLC running out,i woulsd silicon the inner joint just to be sure

just build it up with other tiles until you can put the finishing tiles on it, one tile in the middle to get you to a level you can work from

Or use a quick set render?