Dot & Dab On Pebble Dash

[SeanR01]

I am building a utility room. The external wall of the existing house has a pebble dash finish. Hence, one of the internal walls of the new extension is formed by a section of the existing pebble dash wall. I am hoping to dot and dab plasterboard onto the rendered finish, but do not know how to prepare the wall. I have read various posts and 'normal' walls (block work, whatever) are coated with dilute PVA or dilute SBR.

1. Should I use dilute PVA, dilute SBR or something else prior to bonding the plasterboard onto the pebbledash?
2. What ratio of PVA to water OR SBR to water should I use?
3. Should I allow the dilute PVA or SBR to dry prior to fixing the plaster board?
4. Are there any other methods I could use to cover the pebble dash?

Thanks for your help.
Sean

 

[darrington]

Why not strap the wall with 2"x1" or 2"x2" timber posts,, insulate between the posts as you go if necessary, then fit 12.5mm thick plasterboard sheeting, then tape or skim the wall. You'll have room to fit new sockets too if required. A "far far" better job than dot and dab.

 

[SeanR01]

Thanks for your reply. I have used batton's in the past and prefer the technique, as you do.

However, as the extension size was constrained by the site, I have an internal dimension of 1.9m between the pebble dashed wall and the opposite block wall. I was trying to minimise any reduction in this dimension as I was hoping to install a washing machine, dishwasher and tumble drier in the space; hence my wish to pinch a few more millimetres if possible.

 

[EugeneM]

Hi - what have you done at the very end? I'm facing a very similar challenge now so wondering what's your experience with pebbledash wall plastering. Thank you!

 

[Deleted member 292770]

Hi - what have you done at the very end? I'm facing a very similar challenge now so wondering what's your experience with pebbledash wall plastering. Thank you!

depends whether it’s cavity or solid wall? whether it’s cavity filled and if there’s a cavity tray above. Also whether the wall above is subject to driving rain.

 

[EugeneM]

depends whether it’s cavity or solid wall? whether it’s cavity filled and if there’s a cavity tray above. Also whether the wall above is subject to driving rain.

In my case it's an internal wall now (was external long time ago and hence dashed) all covered by pitched roof (joined into the main roof) above.

I don't want to remove pebbledash as it's hard as rock and some of the bricks behind aren't looking that great. The same time while mortar is very hard to remove, actual stones are quite loose - can remove most of them just scrapping with a chisel.

So basically I'm considering two options now after removing loose stones - either dot and dap or use metal low profile studs with plaster on top.

 

[Deleted member 292770]

safer to go with the studs.
or you could bond a 25mm insulated board to it.