Adding Unibond to mortar for paving?

[Glyn1959]

Hi I read on one site to add a weak solution of unibond to sand and cement mix for laying paving slabs (apparently it helps the mortar stick to the paving). Currently I used 2 xwashed sand, 2 x building sand and 1 x cement plus washing up liquid as a plasticiser. Can I add unibond to this mix aswell??

 

[diggy.1]

Hi M8

I have been doing plastering 1 day a week at college, Finished the 1st year and awaiting to start second year in september.

When using unibond / pva glue in plastering it is designed to seal the wall/ceilling so that when you apply plaster (due to suction) the water is not absorbed into the wall/plaster. The glue goes slightly tacky but it is not a strong glue, I wouldnt think this would help to stick to the slabs in any way.

Your best off just getting a rubber hammer, Put your level over the slab and gently tap the rubber hammer onto slab. If you hit the slabs too hard they can break even with a rubber hammer.

As for the washing up liquid, Its an excellent idea on hot days.

I could be wrong mate but pva/unibond is around £8 for a tub and i dont think it will help in any way strength wise.

 

[Glyn1959]

Cheers for your help!

 

[Thermo]

you dont need to use pva, only if your laying on an existing concrete bed with a wet mix and you need to get a bond on it. even then all you do is give the concrete a coat of it and not put it in the mix. Personally, i use a neat wash of cement to do this.
As for washing up liquid dont do it. it contains salts which can come through and cause problems with efforfescance. get some plasticiesr its cheap and does the job properly.