Page 1 of 1
Posted: Wed Sep 05, 2012 3:46 pm
by Skyman
Hi, I have some left over Indian Sandstone slabs, they are Riven, rough and un-regulated in thickness. I'd like to lay these over some existing exterior steps that are covered with (semi shiny ish) kind of terracotta sort of tiles. I'd prefer to avoid having to remove these existing tiles unless otherwise advised. Is there a type of adhesive that can cope with these conditions?
Rough, porous surface to smooth, exterior. Many thanks for your expert advise. Cheers
Posted: Wed Sep 05, 2012 5:39 pm
by lutonlagerlout
if you prime the sand stone and the steps with SBR
then mix up a 3:1 sharp sand :cement mix with 100ml of sbr in the mix
they will stick like the proverbial blanket
best no more than 30mm overhang
cheers LLL 
Posted: Wed Sep 05, 2012 9:03 pm
by Mikey_C
as well as the above you could also try roughing up the surface of the tiles.
Posted: Thu Sep 06, 2012 9:17 am
by Skyman
Thanks LLL - I had to look up SBR and that sounds like the Mother of all methods. Are there any off-the-shelf ready mix adhesives that will do a similar job? It's just a one-off fairly small front door step. Cheers
lutonlagerlout wrote:if you prime the sand stone and the steps with SBR
then mix up a 3:1 sharp sand :cement mix with 100ml of sbr in the mix
they will stick like the proverbial blanket
best no more than 30mm overhang
cheers LLL
Posted: Thu Sep 06, 2012 9:18 am
by Skyman
Thanks LLL - I had to look up SBR and that sounds like the Mother of all methods. Are there any off-the-shelf ready mix adhesives that will do a similar job? It's just a one-off fairly small front door step. Cheers
Posted: Thu Sep 06, 2012 3:15 pm
by lutonlagerlout
its only about £15 for a 5 litre pot of sbr
worth every penny
just a bit of sand and cement and you are sorted
LLL
Posted: Fri Sep 07, 2012 11:28 am
by Tony McC
There are 'off-the-shelf' adhesives, but when you analyse them, they usually turn out to be sand, cement and a dry form of SBR or its equivalent, and the whole thing costs considerably more than a 5 litre container of the aforesaid SBR.
Most of these 'adhesives' are intended to be used as thing layers, just 1-3mm, and so you get what seems like good coverage from a pack. However, when you realise that bedding for riven, uncalibrated flags will take 5-20mm thickness, all of a sudden you're only getting a square metre or two for every pack, which is why those in the know, use sand + cement + SBR: it's just much better value for money!
Posted: Sat Sep 08, 2012 9:28 am
by Skyman
Thanks LLL & Tony - you've sold it too me.
Should I let the primmer coats dry before assembling?
Thanks again
Posted: Sat Sep 08, 2012 1:37 pm
by lutonlagerlout
let them get sticky
be careful SBR really does stick like **** to a blanket!
LLL
Posted: Sun Sep 09, 2012 10:23 am
by mickg
if you get any SBR on the surface of the paving you need to remove it straight away with lots of clean water and a hand held soft brush rubbing vigorously otherwise you will never be able to get it off the surface of the paving