Prepping a soot-stained wall prior to repainting

[RogerS]

We want to repaint this but need to do something to the underlying soot first. Seems to be a multi-stage process..




1) Dry soot sponge

2) degreaser

Anyone with any experience of doing this ?

Any suggestions as to a degreaser as there are a lot to choose from rnaging from industrial chemicals to Homebase types.

TIA

 

[imageel]

The issue with smoke impregnated walls is that the oils in it will usually result in bleed-through to whatever you overpaint it with.
The usual workaround is to seal it 1st with something like shellac based Zinsser B-I-N

 

[eribaMotters]

You could also try an oil based primer, which could then give problems when you emulsion the wall. Instead of the emulsion a flat eggshell could be an alternative as you can wipe it down.
Another alternative would be stabilising solution as sometimes used before applying exterior masonry paint. This would be expensive as I think it's only available in 5L containers.

Colin

 

[Bingy man]

We want to repaint this but need to do something to the underlying soot first. Seems to be a multi-stage process..

View attachment 173942


1) Dry soot sponge

2) degreaser

Anyone with any experience of doing this ?

Any suggestions as to a degreaser as there are a lot to choose from rnaging from industrial chemicals to Homebase types.

TIA

I’d be having that chimney checked before I did anything . What type of chimney is it class 1 brick built , or pre cast concrete blocks . ??? That excessive amount of staining is typical of products of combustion re entering the room . Solid fuel fires can produce huge amounts of carbon monoxide and 30+ years as a gas engineer is telling me you have a problem .

 

[niall Y]

Thoroughly clean the wall to remove the deposits, When dry use a Zinsser primer , which is more like a white pigmented, French polish. This will act as a stain block, A friend successfully used this to prime the walls of a property that had suffered fire and smoke damage.

 

[littleoaks1]

just for interest as a new member, I was chartered Building chappie before retired and standard stuff was three coats of aluminium wood paint (silver looking stuff) then coat of PVA as primer to aid a bond (glue bonding agent water soluble) then important, to finish, always use Sulphate Resisting Products / cement / plaster as the soot has very high sulphate content- this is the bit that corrodes chimney bricks !
wish i knew more about woodwork but hobby is progressing
old timers apparently used to spread horse muck diluted with water then lime plaster but probably not a good idea now.....

 

[littleoaks1]

just for interest as a new member, I was chartered Building chappie before retired and standard stuff was three coats of aluminium wood paint (silver looking stuff) then coat of PVA as primer to aid a bond (glue bonding agent water soluble) then important, to finish, always use Sulphate Resisting Products / cement / plaster as the soot has very high sulphate content- this is the bit that corrodes chimney bricks !
wish i knew more about woodwork but hobby is progressing
old timers apparently used to spread horse muck diluted with water then lime plaster but probably not a good idea now.....

ps looking at the picture i would strongly suggest a new flue liner as the mortar has probably gone from the joints inside the stack . this can allow hot gasses to penetrate the brickwork and char or even ignite hidden trimmer timber joists in floor or roof.

 

[RogerS]

Thoroughly clean the wall to remove the deposits, .....

Therein lies the rub. Exactly how, I uess, is the real question. Lots of stuff out there suggesting how but I was hoping to find someone who could say 'this or that did/didn't work'.

 

[RogerS]

I’d be having that chimney checked before I did anything . What type of chimney is it class 1 brick built , or pre cast concrete blocks . ??? That excessive amount of staining is typical of products of combustion re entering the room . Solid fuel fires can produce huge amounts of carbon monoxide and 30+ years as a gas engineer is telling me you have a problem .

It's 1750 Georgian stonework

The reason (and nothing we'll be doing about as we're moving) is that my builder didn't do the internal 'throat' (if that's the right word) properly.

 

[RogerS]

ps looking at the picture i would strongly suggest a new flue liner as the mortar has probably gone from the joints inside the stack . this can allow hot gasses to penetrate the brickwork and char or even ignite hidden trimmer timber joists in floor or roof.

'Flue liner ' ....not in 1750 !

 

[oakhouse]

Flue liner is corrugated flexible tube which is dropped into chimney stack and sealed top and bottom
This effectively removes leakage from masonry flue
Downside is that if a thatched roof then the flue temperature will probably be too high to restrict sparks from leaving chimney pots this if the case should be discussed with insurers for options should you have thatch
Hope this helps

 

[Superduner]

This may not be completely applicable in your case as you need to repaint, but oven or BBQ cleaner will get it off. I spent a very uncomfortable 3 days recently cleaning 200 years worth of wood soot off my limestone inglenook fireplace. Oven cleaner, kitchen roll and a stiff brush worked wonders.
Maybe a watered down solution?

 

[XTiffy]

Some years ago I repainted a room that had years of wood smoke from an open fire. I started off trying to clean with sugar soap and it caused an un-holy mess (Client was a man of the cloth). Then I discovered Zinsser, heaven, my, get out of jail card. So I would agree with Imageel above. Do not clean but seal it in. I have used these Zinsser products ever since and I can't recommend them too highly.

 

[SeeO2]

Some years ago I repainted a room that had years of wood smoke from an open fire. I started off trying to clean with sugar soap and it caused an un-holy mess (Client was a man of the cloth). Then I discovered Zinsser, heaven, my, get out of jail card. So I would agree with Imageel above. Do not clean but seal it in. I have used these Zinsser products ever since and I can't recommend them too highly.

I second this, they are excellent products I’ve used quite a few times, cover anything.

 

[highwood122]

just for interest as a new member, I was chartered Building chappie before retired and standard stuff was three coats of aluminium wood paint (silver looking stuff) then coat of PVA as primer to aid a bond (glue bonding agent water soluble) then important, to finish, always use Sulphate Resisting Products / cement / plaster as the soot has very high sulphate content- this is the bit that corrodes chimney bricks !
wish i knew more about woodwork but hobby is progressing
old timers apparently used to spread horse muck diluted with water then lime plaster but probably not a good idea now.....

used cow slurry myself

 

[Chris Harris]

Sealing (or hacking off the plaster, sealing and replastering) is essential because it is likely that there is soot between bricks and soot is hygroscopic. If you clean really well you may not get staining immediately but after a while damp patches will appear

 

[RogerS]

This may not be completely applicable in your case as you need to repaint, but oven or BBQ cleaner will get it off. I spent a very uncomfortable 3 days recently cleaning 200 years worth of wood soot off my limestone inglenook fireplace. Oven cleaner, kitchen roll and a stiff brush worked wonders.
Maybe a watered down solution?

Thanks for the tip re cleaning limestone as that is also on the agenda.

Many thanks to everyone for the suggestions.

 

[okeydokey]

Another vote for zinsser, I used on water stained ceilings before emulsion after the ceiling was dry
2 coats did it

 

[Inspector]

I must be the only one bugged by the answer in post #9? The OP, a home owner has had a bad job done on his chimney/fireplace and is covering up the result so he can get more money and move. That leaves the new owner to resolve it eventually when it becomes a problem for them. To me that isn't ethical behaviour and I couldn't live with myself.

My dismay over.
Pete

 

[Bingy man]

I must be the only one bugged by the answer in post #9? The OP, a home owner has had a bad job done on his chimney/fireplace and is covering up the result so he can get more money and move. That leaves the new owner to resolve it eventually when it becomes a problem for them. To me that isn't ethical behaviour and I couldn't live with myself.

My dismay over.
Pete

Thank you - i didnt comment any further as i was in part shocked at the reply and also not in any mood to start a thread argument .however I thought it strange how anyone would leave a potentially dangerous flue for the new owners to discover and even worse to mask the problem with a coat of fresh paint so the problem wont be obvious .. we