What SBR Primer for wall plastering?

[elbow]

Hey guys

Im looking for a recommendation. I want to plaster a concrete internal wall and am led to believe i need a primer to provide adhesion for some plaster - What would you guys recommend?

[JacobZ]

Hi @elbow,

Welcome back and thank you for your question.

I've contacted our suppliers and unfortunately they do not have a specific SBR primer suitable for this purpose. I note that products are available overseas, but here in Australia and New Zealand, this technique is not typically used. 

Bondall has advised me that you can use Bondall 1L BondCrete Cement Additive for this purpose. Their instructions are:

1. Apply sealer coat of BondCrete (One part BondCrete to four parts water) and allow to dry.
    
2. Apply bondcoat of BondCrete (Four parts BondCrete to one part water) and while still wet or tacky, carry out topping or patching.
    
3. Use BondCrete admixture (One part BondCrete to 10 parts water) in the topping/patching mixture in place of normal water.

Please let me know if you have any other questions.

Jacob

[elbow]

Hey Jacob

Thank you for your great response - Is the technique in Oz using the bondall stuff, or is that something else entirely. I notice there are a few products around but im not sure specifically what they're for. For my purposes i was thinking the SBR is an adhesive in-between the layers? I assume its necessary or something sort of adhesive is?

[JacobZ]

Hi @elbow,

Generally, the technique in Australia is to batten out the wall then sheet over the top with plasterboard. If this is possible, it will give you the the best finish possible, but you would lose the width of the batten plus the width of the plasterboard from the room.

BondCrete is a general-purpose cement additive that can be used in a number of applications, and I've been advised by their technical team that they are happy for it to be used for this application. It will create a seal coat over the wall that the plaster would bond to much better than the porous concrete.

There are SBR containing products produced by Ardex, that are able to be ordered off range, but they only come in 20L drums and are prohibitively expensive due to their usual use in industrial and commercial applications. I am happy to advise what they are, but if you are only doing a single wall, there would be a lot of waste.

Let me know what you think.

Jacob

[elbow]

Hey Jacob

Thanks again for a detailed reply. The job itself is only to put in new reveals and sills for newly installed windows but i have to build up the sides, bottom and top edges of the walls around the window - so all im really doing is using plasterboard for them and plastering over the top. but because im building new edges all around, i need to merge all the new stuff into the existing surrounding walls. 

[JacobZ]

Hi @elbow,

BondCrete should be perfect for this as it will give the plaster a better surface to cling to. Concrete is porous and because of this it "breathes". The BondCrete will create a seal that will stop this "breathing" from affecting the plasters adhesion. 

I look forward to seeing the finished results.

Jacob

[elbow]

Hey Jacob, top man, thank you so much for your help, very much appreciated  😁 🙏 oh and BTW, what plaster would you recommend, i was looking at some gyprock stuff  https://www.bunnings.com.au/gyprock-csr-10kg-base-coat-45_p0730825   but then you have to buy different ones for each later, is there just a simple one product does all?