Wallpaper Prepping.

Tinders

Tinders

Tinders

Soldato
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There's a voice that keeps on calling me.
Hey Folks,

Looking for some decorating advice, ive had a bit of a mould problem in a bedroom in my decrepit old house, specifically behind cupboards. The walls are papered and prior to cleaning with HG Mould cleaner, i thought i would stick some of the paper back with some glue, but the damn thing doesnt want to stick.

So im going to plan B and decided to strip the walls, give them a good wash down with bleach, and put some thich lining paper on. Looking at the plaster, it doesnt look like the plaster ive seen in my old house. Whats best way of prepping the wall prior to papering, this room was papered 15 years ago if memory serves me right.

The pic is of an outside facing wall next to the chimney. House is an old 1890's property.

7MxNIRV.jpg
 
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Only guessing but did you allow the paper to soak before trying to stick it back down, typically you'll need to leave paste on the paper for 10-15min (more depending on how thick the paper is) before applying/sticking it to the wall.

As for repapering and prep work it depends on what state the walls are in after you've removed the old paper, obviously holes and cracks will need to be filled with thicker paper being more forgiving in terms of what defects it can hide but other than that you can get away with very little prep work, just the typical remove any flaking loose materiel, fill holes/cracks, clean the walls so they're dust free (maybe wash them down with a bit of sugar soap), and get papering.
 
Looks like a parge coat. Given the age of the property it might be lime based, so be careful with sealing it up. It’s supposed to be breathable. My 50s house has it. Cement render on the outside, solid brick walls, cement parge on the inside.

If you’re getting mould behind cupboards it’s probably because of bad air circulation. Some positive air ventilation might help, as well as air bricks/trickle vents on your windows.
 
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Cillit bang do a black mould remover which my wife says is very good. Regarding repapering, I would avoid for a bit preferring to paint with an emulsion once the wall has fully dried and been made mould free. Ventilation improvements are recommended.
 
How do you know water isn't getting through the walls to make the paper damp?

I wouldn't call myself an expert, but my suspicion is that water may be getting through your walls, making any paper that sits on top of it slightly damp and prone to mould.

If it was me, I would be thinking about anything that needs to be done to the outside, e.g. walls or roof, to prevent water ingress into the wall. Then on the inside, I would be looking into whether coatings can be applied to prevent water ingress / dampness, and then replastering. Finally, I would paint the walls instead of using wallpaper, as wallpaper is more susceptible to mould.
 
I would clean the walls, then prime them with a shellac based anti-damp paint (there are plenty of good makes around - Zinsser, Thompson's.....). The reason for that is that the damp is probably coming through the wall. (It's not evaporating behind the cupboards through lack of air.). Sealing the walls will stop the damp entering the house and eliminate the possibility of this happening again. The primer will also act as a perfect base to stick the wallpaper to. You could seal the walls on the outside, but this would take a very long time to affect the inside. Long term, though, it would certainly be worth doing. An external (transparent) sealer or an oil based masonry paint.
 
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radderfire said:
How do you know water isn't getting through the walls to make the paper damp?

I wouldn't call myself an expert, but my suspicion is that water may be getting through your walls, making any paper that sits on top of it slightly damp and prone to mould.

If it was me, I would be thinking about anything that needs to be done to the outside, e.g. walls or roof, to prevent water ingress into the wall. Then on the inside, I would be looking into whether coatings can be applied to prevent water ingress / dampness, and then replastering. Finally, I would paint the walls instead of using wallpaper, as wallpaper is more susceptible to mould.
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It may be that. But him saying it’s especially bad behind cupboards makes me think it’s an airflow issue rather than penetrating damp. It could be a case of both though.
 
Mason- said:
It may be that. But him saying it’s especially bad behind cupboards makes me think it’s an airflow issue rather than penetrating damp. It could be a case of both though.
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In a house of that age, it almost certainly is. The wall won't be a cavity wall, so it will be naturally a tad damp. Any lack of air on the inside and you have a problem. I mean, I have seen this problem with a cavity wall, let alone a solid wall.
 
its a 3 storey house and this room is on the middle room, i'd be surprised if damp is coming in from outside, theres certainly no blown bricks that i can see, maybe the mortar??

im a bit concerned about sealing the walls, ive read conflicting info for sealing walls in solid brick constructions. Thnks for all the tips:)
 
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Tinders said:
its a 3 storey house and this room is on the middle room, i'd be surprised if damp is coming in from outside, theres certainly no blown bricks that i can see, maybe the mortar??

im a bit concerned about sealing the walls, ive read conflicting info for sealing walls in solid brick constructions. Thnks for all the tips:)
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So it's not an outside wall? In that case, it's a little odd because usually condensation doesn't cause damp on an internal wall. Could the other side be particularly cold?

There are sealants that stop the ingress of stains and mold but still allow the wall to breath. Most damp paints are like that. Some have anti-mold added to them to further inhibit mold.
 
Tinders said:
Sorry meant it’s a room on the middle floor, the wall is an outside wall.
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Then water can come in from the outside.

I once had a wall that had a cavity (and yours probably doesn't) that suffered the same problem. There was damp behind furniture and so on. The reason was the exterior wall pointing was degrading and so the exterior wall was very damp just from rain hitting it. The vapour managed to cross the cavity and make the interior wall just a little damp. It wasn't enough to cause alarm, except behind wardrobes and so on. In your case, you don't have a cavity, so it takes even less for the interior wall to be a touch damp. The simplest thing to do is just seal it. At some point you could seal the exterior. Either way, if you use a "breathable paint"/ sealant, then there won't be any issues.
 
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So what zinsser paint ould you recommend. Ive used BIN in the past with good sucess so i like the brand. Cover stain or permawhite? It will be papered, as the walls, whilst sound, need a skim.
 
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Tinders said:
So what zinsser paint ould you recommend. Ive used BIN in the past with good sucess so i like the brand. Cover stain or permawhite? It will be papered, as the walls, whilst sound, need a skim.
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The last one I used was Thompson's Stain Blocking Damp seal. Very similar to Zinsser, its a shellac based paint that is so easy to apply and leaves a lovely finish.
 
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