Dot and Dab over existing papered rendered wall - bad idea?

Hi all,

Recently had chimney breast removed and its not posisble for this to be patched into the existing plaster as finished level protrudes more than rest of wall.The 'old plaster' isn't board and skim but a proper render and top coat I suppose and is sound. It has woodchip over top.

My intention was to rmove paper and then dot and dab on top of the old plaster but having removed some of the woodchip it seems to be wall papered over a sort of salmon pink gloss - no idea why but I was wondering whether could I dot and dab onto the wallpaper. It sounds a bit backward to me but im wondering if it would be worse to remove it and dot and dab on this gloss? Never had any prob with paper i.e. doesnt seem to come off easy at all.

I want to really avoid taking back to brick cos of the mess and likelihood of mucking up floors. I hadn't really thought about it till reading this post and wanted to know opinions?

//www.diynot.com/diy/threads/please-help-plasterboard-to-brick-wall.272778/

Thanks

If you consider that the plasterboards although dot/dabbed, are really being held/fixed to wall by whatever the paper was pasted with, would you consider it a good idea?

OP,

You are going about it the wrong way, and will possibly cause yourself a bit of grief and expense.

Using a lump hammer and a brick chisel will allow you to take the chimney breast/flue protrusions back to a just less than plane with the rest of the wall.
While doing this levelling back you must attempt to knock off or wire brush all traces of soot.

You two coat with SBR the old previously sooty flue line, and when the second coat is tacky you render up in sand and lime - or sand and cement.

Scar and slit the wallpaper back to plaster with a Stanley knife - vertically and then horizontally and then repeatedly wet it to soaking point.
It should budge. If not do the same thing all over again and it will slide off. Wash and rinse the wall of all wallpaper paste.

Now skim the render patch.

All remaining paint to be sanded - with a belt sander if possible.

PBOD,

Firstly many thanks for reply an I agree mate, but also worry that removing paper and leaving paint will cause same issue if the paint hasn't adhered properly. I'm thinking remove the paper and paint if possible after all it doesnt need to be a neat job. I suppose I could also knock out sections back to brick and dab into that. What you reckon?

Ree, Thanks for the response. To take the brick in the chimney breast back to same plane as rest of existing wall really is a nightmare. The brickwork in the breast nowhere near matches the rest of the wall but I had hoped when taking it down that what you describe would have been what I would be able to do. But as always what you actually find is far from ideal.

Thanks both again.

Just dot and dab over the paint. If the paint has been under the paper for a while its not going anywhere I am dot and dabbing my old kitchen and most of the old stone walls are painted and no probs,,,

Just dot and dab it. If in doubt mark where your dabs are and put a screw or two into rawlplugs through the dabs into the wall. You don't really need it though. Roy is right.

1. never D&D over wallpaper, its the equivalent of plastering over wallpaper.

2. If the remains of the c/breast project beyond the wall plane then how far out do you propose to set the plaster board?

3. The idea of D&D is to get the p/b as tight to the wall as possible. Any contact with soot or damp will bridge & bleed thro to the decorated surface.

4. D&D'ing has come in for some heavy technical criticism over the last few years - esp. where its on outside walls.

5. Moisture is entering thro the p/b into the D&D "cavity" and condensing on the wall - this condensation is causing mould.
Sometimes, when the wall is exposed, the wall has then been found to be a sheet of slimy mould. This has gone to the courts.

6. Correct fire proofing top and bottom with p/b adhesive is rarely carried out - this can invalidate insurance fire claims.

7. A number of councils and housing associations will no longer allow D&D work.

8. A number of larger plastering contractors will now only set p/b against some kind of frame and vapour barrier etc. - there are still unresolved technical difficulties. There are still disputes over best practice.

ree said:

1. never D&D over wallpaper, its the equivalent of plastering over wallpaper.
5. Moisture is entering thro the p/b into the D&D "cavity" and condensing on the wall - this condensation is causing mould.
Sometimes, when the wall is exposed, the wall has then been found to be a sheet of slimy mould.

Click to expand...

My flat was D&Dd over wallpaper. It's fairly solid, but fortunately easy to get off if I can get a wallpaper stripper under the wallpaper layer.

I say fortunately because I have mould under the pb and they plasterboarded over lots of the power sockets.

Rather than taking back to brick, if there is a skim coat that may well chip off fairly easily, and the wall can then be built up with layers of plaster.