Waterproofer

[Mac82]

Just wondering weather you should put a waterproofer in the sand and cement render mix? Also what the best mix is 3.1? Been plastering 13 years just hardly done any sand and cement render! Cheers.

 

[leebo02]

i always put waterproofer in my scratch coat i use 4- 1 +water proofer for scratch coat and 4-1-1 for top coat

 

[Mac82]

Cheers pal just wasn't sure if I needed to put any additive in the mix old bhoy told me it Could make the render crack in time?!! Is that 4 sand 1 cement 1 lime?

 

[malc]

we only use waterproofe additive depending on what finish is required and the size of the area to be rendered

 

[leebo02]

yes 4 sand 1 cement 1 lime,, i also put waterproofer in top coat as well,,, using admix will make the gear easier to use,, this is the mix i use and i never get any problems,,, every one you ask will have a different mix they like to use

 

[Mac82]

Thanks for that pal much appreciated

 

[basset]

I use 4-1 with abit of waterproofer in the scratch. Then use feb mix on the top coat.

 

[stiltwalker]

we never use feb on external work and as malc said amounts of waterproofer we use is dependent on conditions and size of the walls

 

[superspread]

Like leebo said but make sure you don't use master create cement or an equivalent ,just good old fashioned paper bag opc

 

[superspread]

Mastercrete ,bloody ipad

 

[johniosaif]

I would only use waterproof in the scratch if there was warm weather or a big amount of suction or if it was a big area. On cold damp walls I would put it in the top coat, my scratch would be 4/1 sand cement on solid walls concrete or brick, 6/1 on celcon or thermalites. Top coat 5/1 over the 4/1 a week later, 6/1/1 on cel on a week later,
don't mix waterproofer and lime together or waterproofer and plastizer, lime and plastizer aerates the mix,