Removing wallpaper paste before painting

ashe

Just wanted to check my method to make sure there isn't a better way. Whole room is painted apart from one wall which was papered, going to go to full painted.

paper came off largely fine, only a bit of the backing stayed behind on one strip and some around sockets so have sponged the wall with soapy water and a little sugar soap then used a scraper to get the paper residue off

Fill any obviously marks or dings 

then orbital sand the entire wall 80 grit as it's a bit orange peel textured, then quick 120 grit, then final sugar soap and rinse 

I was then thinking to do a cost of Zinsser gardz just to be safe, and because other walls have been problematic in the house so better safe than sorry. 

Anything extra to do?

ThisIsWeird

That sounds very thorough. By the time you've 80'd and 120'd, there shouldn't be any paste left on there! But, if there is, it'll be a 'mare when you apply emulsion paint.

Your call - if, by the time you've sanded, it's very obvious you are back down to the 'bare' wall - either plaster or an earlier paint coat - then you should be safe. Any doubt - then Gardz.

If there is obvious paste left on the wall after the paper has been stripped, then try and shift as much as you can before you sand. Either wet cloths, repeatedly rinsed out, or even a light going-over with the wallpaper steamer - that swells any paste very quickly, and it can be scrapped or damp-clothed off. Don't 'blow' the plaster with too much steam, tho'.

You should feel when the paste has been removed - the damp cloth will drag rather than slip! But plenty rinses is the key. A drop of fairy or sugar soap will probably help too.

Don';t forget yer marigolds...

Mistral001

It seems like you are doing more than enough preparation work, but it depends on the condition of the wall and type of paste etc.

Years ago I removed paper and redecorated with paint several rooms in my house (1950's vintage). I was very careful about removing the paste with water and scraping etc, so I was surprised to see how little preparation a professional painter decorator did when I later got one in to do the same job on another room.  The deal was that I would be his helper while he did the job.  He just scraped off the paper, filled in any holes left by old picture hanging nails with (very) quick-drying filler and started painting straight away.  The finished job was perfect.  After that I thought what do I know about decorating? 

ashe

Mistral001 said:

It seems like you are doing more than enough preparation work, but it depends on the condition of the wall and type of paste etc.

Years ago I removed paper and redecorated with paint several rooms in my house (1950's vintage). I was very careful about removing the paste with water and scraping etc, so I was surprised to see how little preparation a professional painter decorator did when I later got one in to do the same job on another room.  The deal was that I would be his helper while he did the job.  He just scraped off the paper, filled in any holes left by old picture hanging nails with (very) quick-drying filler and started painting straight away.  The finished job was perfect.  After that I thought what do I know about decorating? 

I did it the other way round and trusted a professional. He did a terrible job and he was far from cheap 😂 I've seen a lot of comments from people saying they've painted over some paste and it crazes the paint, so I'd rather do it right then have to do it all again 

FreeBear

ashe said: then orbital sand the entire wall 80 grit as it's a bit orange peel textured, then quick 120 grit, then final sugar soap and rinse

Anything extra to do?

With a gypsum plaster finish, a quick whizz over with the sander should be OK. With a lime plaster, you run the risk of exposing the softer friable base coats which will need a lot more filler. With a drywall, all too easy to dig in and leave large gouges.

Just make sure you wear a decent quality dust mask, and seal the room before you start to sand. The dust will go everywhere, so be prepared to do a deep clean of the entire house once done.

ashe

FreeBear said:

ashe said: then orbital sand the entire wall 80 grit as it's a bit orange peel textured, then quick 120 grit, then final sugar soap and rinse

Anything extra to do?

With a gypsum plaster finish, a quick whizz over with the sander should be OK. With a lime plaster, you run the risk of exposing the softer friable base coats which will need a lot more filler. With a drywall, all too easy to dig in and leave large gouges.

Just make sure you wear a decent quality dust mask, and seal the room before you start to sand. The dust will go everywhere, so be prepared to do a deep clean of the entire house once done.

It's standard plaster, a fairly thin coating over strammitboard straw walls 

I've been sanding away with my mask on and use a dust extractor to a shop vac so there isn't too much dust 

it's very bumpy - the whole house has been - guessing they used a thick roller for 2 coats with no light sand inbetween and peppered with occasional dents or poorly filled previous holes, so sorting it all as I go and filling in a few cracks above the window while I am at it, takes more than a quick whizz unfortunately as it is so bumpy; this exaggerates it as it is side lit but you get the idea!



but first time dealing with wallpaper paste so want to make sure this paper goes smoothly! Literally 😂

ThisIsWeird

ashe said:

but first time dealing with wallpaper paste so want to make sure this paper goes smoothly! Literally 😂

This 'paper'? You mean 'painting'?

Yes, that's rough, but should be easily sandable. It does not have to be fully flat. Try it straight off with 120 grit, in that very area, and not going too far with it. Take a similar side-lit pic to show us the difference (ie also show an unsanded bit).

Folk on here will shout 'STOP!' at the right time :-)

35har1old

ashe said:

Mistral001 said:

It seems like you are doing more than enough preparation work, but it depends on the condition of the wall and type of paste etc.

Years ago I removed paper and redecorated with paint several rooms in my house (1950's vintage). I was very careful about removing the paste with water and scraping etc, so I was surprised to see how little preparation a professional painter decorator did when I later got one in to do the same job on another room.  The deal was that I would be his helper while he did the job.  He just scraped off the paper, filled in any holes left by old picture hanging nails with (very) quick-drying filler and started painting straight away.  The finished job was perfect.  After that I thought what do I know about decorating? 

I did it the other way round and trusted a professional. He did a terrible job and he was far from cheap 😂 I've seen a lot of comments from people saying they've painted over some paste and it crazes the paint, so I'd rather do it right then have to do it all again 

That can happen if the previous coat was a silk emulsion 

FreeBear

ashe said:

Mistral001 said:

It seems like you are doing more than enough preparation work, but it depends on the condition of the wall and type of paste etc.

Years ago I removed paper and redecorated with paint several rooms in my house (1950's vintage). I was very careful about removing the paste with water and scraping etc, so I was surprised to see how little preparation a professional painter decorator did when I later got one in to do the same job on another room.  The deal was that I would be his helper while he did the job.  He just scraped off the paper, filled in any holes left by old picture hanging nails with (very) quick-drying filler and started painting straight away.  The finished job was perfect.  After that I thought what do I know about decorating? 

I did it the other way round and trusted a professional. He did a terrible job and he was far from cheap 😂 I've seen a lot of comments from people saying they've painted over some paste and it crazes the paint, so I'd rather do it right then have to do it all again 

https://twitter.com/chelseadotgov/status/1434360473722499072

Paid for a "professional" to do some plastering a while back. The quality of the job left a lot to be desired, and I thought "I can do better than that". After doing a short (free) plastering course, I can.

Postik

My old house was covered top to toe in wall paper (even the ceilings).  I had most of the ceilings re-plastered but the walls I washed down, sanded, washed down again and they were fine.  As someone mentioned above, you could "feel" with your hand if there was still paste on the wall.

I only ever had problems with one single wall in the whole house where the paint just cracked every time it dried.  In the end I put lining paper on that wall.

John_the_Boy

I used wall paper remover (dial from B&Q) and it turned the paste gooey so I was able to wash 80% off once I removed the paper and then followed up with a light sand once the wall had dried. 5 years later the paint is still on the wall and isn't flaking so it must have worked ok LOL.