DotnDab or Browning

[ibruceuk]

Hi there,

Whilst removing wallpaper from the lounge some plaster came with it. I then removed all plaster that was blown and am now left with an area about 2.5 Metres by 2 Metres that is down to brick, it is quite irregular though, not perfectly rectangular..

I'm considering two options.... Firstly browning and then skim (I'm not a plasterer) and secondly DotnDab board and then fill the edges to meet the other plaster with browning and then skim the lot.

Would it be a problem that part of the wall is original plaster and another part board??

Cheers,

Ian

 

[Richard C]

Personally I would go for a base plaster & skim; you could attempt a patch & blend but it can be difficult to make invisible & it's more than likely to crack around the join again in the future. It’s usually easier & no more time consuming to fill out level with the current plaster, tape the joins & then re-skim the whole wall. Rather than browning, use Bonding, Hardwall or even render depending on the type & the condition of the brickwork; is it actually bricks or is it blocks? If you dab in a lump of PB, there is always the risk it will be visible in the finished wall if you don’t get it right &, again, there is a very high risk of cracks appearing around the join due to different rates of expansion between the original plaster & the PB. It will also sound hollow when tapped & hanging things on that part of the wall becomes more difficult.

Are you going to attempt this yourself? What % of the wall has the plaster come away & what’s the rest of the wall like? It may be a better option to strip the whole wall back & start again!

 

[ibruceuk]

The wall is probably going to be papered over in the end, so minor cracking wouldn't be an issue.

The wall is pretty old brick (1880's) and has a basic timber frame kind of embedded into the brick but the timber is at 4 foot centres. The bricks are very very porous.

The current plaster varies from about 12mm thick at the edges of the missing section to about 25-30mm thick in the middle as the wall is a little bowed.

I have repaired a smaller section on another wall with browning and I found browning a little difficult to do and to make it stick to the wall even after much PVA and soaking of the wall. I've used bonding in the past and found it easier as it sticks like s*** to a blanket but I didn't think I could use it on such a porous background.

I was thinking boarding it to help with the varying depth too and the fact it'll help me keep it flat, I'm not entirely confident with such a large area of being able to keep it level...

 

[Richard C]

If you work to fixed guides & the current wall building up in layers, you should be able to keep it flat & level. I never use Browning now, Hardwall is a much better all rounder; Bonding is intended for low suction backgrounds but I always use it if the walls are in poor condition as it helps bind it all together. As long as you seal a high suction substrate well with PVA, let it dry thoroughly & then PVA well before you plaster, it’s usually fine. You may have to keep damping down (not too much though!) & working the surface of the first coat as it starts to go off as it can sometimes start to craze a little; the second coat behaves normally & then I skim over that but do it all in the same day.

I would tack some wire mesh over the timber frames as plaster doesn’t really stick to wood very well! If the current base is render, you may be better going for that but it’s not so easy to work with. I can understand your apprehension but it seems rather a shame to D&D lumps of PB on such an old wall! It'll also be good practice for you