Sbr or plasticiser

[richie_jones]

Hi

I`m now 4 days into my paving project and after having to build 2 walls and leveling off the ground i`m nearly ready to start laying my indian sandstone paving and setts. I have 2 ton of sharp sand and was going to lay the paving on a semi dry mix. My question should i be using plasticiser and if so am i better using SBR?.

[GB_Groundworks]

sbr is generally used when adhesion is critical and the area is either highly trafficed or exposed such as copings that aren't held on all sides say on top of a wall, for flags that are on a full bed and jointed plasticiser will do just fine. sbr is about about £15 for 5 litres and recommended application is 5-10 litres per 25kg of cement so it would add a lot to your cost.

[richie_jones]

I have copings, and slabs laid on there side to tidy up a small breezeblock wall. I`ll use SBR then for these only. Do i still need to add plasticiser to the bedding material?

[GB_Groundworks]

yes the plasticiser will strength your mix and make it more workable and easier to lay your flags