Wall prep for Wedi Board

[cabbie65]

Hi. I posted a thread yesterday but hadn't received any answers. Probably says more about the question than anything else!! Anyway, I have hacked the plaster off the wall so we are back to the blockwork. I'm able to get Wedi board where I am from Topps Tiles, however, they advised me that the boards need to be fixed with a solid bed of Adhesive. Looking on Wedi's website it states that you can Dot and dab then fix with screws. I just wondered what your experience is with this. Also, I assume I would need to prime the wall before dotting and dabbing the boards. Is this the case, if so is there are particular primer I would need or just follows adhesive manufacturers instructions. Many THanks
[automerge]1581607027[/automerge]
Sorry, quick additional question. I'm also able to get Kerdi Board near me, is one better than the other. I presume Kerdi can also be dot and dabbed and mechanically fixed? Thanks again

 

[Boggs]

I believe Topps only stock 6mm wedi which can only be solid bedded.
I think you need 20mm if you want to dot and dab them.

@acaciaguy, @Tony_C you guys did the Wedi course did they cover this?

 

[cabbie65]

I believe Topps only stock 6mm wedi which can only be solid bedded.
I think you need 20mm if you want to dot and dab them.

@acaciaguy, @Tony_C you guys did the Wedi course did they cover this?

Ok, Thanks Boggs. Is this true of most backer boards, dot and dab needs to be a bit thicker?

 

[Boggs]

I mainly use Delta Board, 12.5mm boards can be fixed using the dot and dab method.

I would recommend using a rapid set adhesive and prime first with a sbr/primer from the same manufacturer as the adhesive.

 

[Tony_C]

I believe Topps only stock 6mm wedi which can only be solid bedded.
I think you need 20mm if you want to dot and dab them.

@acaciaguy, @Tony_C you guys did the Wedi course did they cover this?

Yes you can dot and dab the bigger wedi wall boards and mechanically fix them. I believe i'm banned from mentioning much on wedi subjects though because i done the training but have a glance here...

Uneven surfaces – wedi.de - https://www.wedi.de/en/area-of-application/interior-building-board-applications/wall-applications/uneven-surfaces/

 

[cabbie65]

Thanks very much guys

 

[cabbie65]

Hi again guys. further to our previous message, I went the whole hog and took the plaster off the wall and went back to the blockwork. You can see from the pictures that I'm still quite a way out, about 15mm at the bottom. I just wanted to check that I am left with little choice but to Dot and dab rather than solid bed a wedi board. Thing is I wanted to keep the board thickness to a minimum, I simply dont have room for 20mm wedi plus dabs , tiles etc . Am I ok to just use 12.5mm plaster board and mechanical fixing or is it worth using Marmox which I believe can be D&D'd at 12.5. Are there any other boards which can be fixed with dot and dabs at 12.5mm. Sorry if these are stupid question but want to get this right. Tnanks

 

[cabbie65]

So after my last thread, I ended up buying 12mm Balboards from CTD. I just wondered if anyone has any experience with these. The smooth side seems too smooth to get a good bonding surface with the adhesive. I know you are to fix mechanically also but even so? Also, I know in the installation video the board is fixed with a solid bed, however, the technical sheet also states for uneven block work tile adhesive can be used in addition to screws. Does this mean you can use dabs or a thick bed? Any advice would be gratefully received.

 

[J Sid]

Smooth side in , tough side out as it says on board

 

[cabbie65]

Hi JulianSidney. Sorry, I have been away just wanted to thank you for your response. Balboards are up, dot and dabbed and screwed. Really easy to cut too. Thanks again.