Help needed, removing en-suite and black mold

[TheEnquirer]

Hi All,

I’m in the process of completely removing an en-suite bathroom, and while taking off the tiles, I’ve come across some big holes (not caused by tile removal) and patches where the plaster has come off. I’ve also spotted some black mold, which is concerning. I haven’t finished yet, so I’m a bit worried about what else I might uncover.

The internal walls seem to be some form of lath and plaster, similar to the ceilings, but I’m not entirely sure of the material.

I have two main questions:

1. Wall repair:
How should I go about repairing the walls?
I’m considering using a ready-mixed filler like Toupret, as I’ve never worked with powder fillers and don’t know if I’d mix it correctly. Would this be sufficient, or should I be using a lime-based filler instead?

2. Black mold treatment:
I plan to have the walls skimmed over, but before that, should I treat the mold with something like Zinsser Mould Killer & Remover Spray? Would I need a specific primer before the plaster skim, or is mold treatment alone enough?

Any help or guidance would be much appreciated!

 

[JohnD]

The internal walls seem to be some form of lath and plaster, similar to the ceilings, but I’m not entirely sure of the material.

How old is the house?

I can't see any sign of L&P in your pic. Are you in or near Somerset?

 

[RrogerD]

What are your plans? Are you removing the ensuite entirely and reverting back to a bedroom / closet etc or, are simply replacing the ensuite / upgrading it, re-tiling etc?
I'd crack on with the whole removal aspect (tiles, units etc) and then see where you're at. If the base plaster is generally sound, albeit friable and dusty then simply stabilise with sbr and skim over.
You need to remove any unstable/loose base material. It may mean hacking the whole lot 'back to brick'.
Personally, I very rarely hack entirely back to brick. If I do it tends to be small areas only.

 

[RrogerD]

What are your plans? Are you removing the ensuite entirely and reverting back to a bedroom / closet etc or, are simply replacing the ensuite / upgrading it, re-tiling etc?
I'd crack on with the whole removal aspect (tiles, units etc) and then see where you're at. If the base plaster is generally sound, albeit friable and dusty then simply stabilise with sbr and skim over.
You need to remove any unstable/loose base material. It may mean hacking the whole lot 'back to brick'.
Personally, I very rarely hack entirely back to brick. If I do it tends to be small areas only.

When you get the plasterers in you need to be 100% clear as to what you want doing. I guarantee they will simply board over the whole lot and skim rather than the effort of patching first.

 

[noseall]

Any help or guidance would be much appreciated!

INSULATE!

 

[TheEnquirer]

@JohnD
House was built in the late 1900s, I’m in Surrey. It’s got lots of fun stuff in the walls. Like flint lol
@RrogerD
I’m going to remove the tiles and whole bathroom completely and take it back to being a bedroom. I mean technically I’m going to move it to the other side of the bedroom but I will put a stud wall up and create new bathroom area which will mean running pipes etc. I’m not thinking about that now that though, I want to focus on this.

I will do the patching myself. I will find a plaster that will just skim over. The dimensions of this house are very small 4x4m squares rooms.
@noseall
I might insulate but my focus is repair the wall and fix the black mold. Due to the age of the house I need to think about how I insulate later on.

Thanks for the quick responses.

 

[JohnD]

The black mould is simply due to damp. Mould spores are in the air, everywhere, all the time. Given a comfortable temperature, and damp conditions, they will grow. It is very common for bathrooms to have enough damp, usually because they are not ventilated enough.

Steamy showers create vast amounts of water vapour, and need a much more powerful extractor, used more often and for longer, than is traditional in UK bathrooms.

Warm, insulated walls are less conducive to condensation than cold ones.

 

[noseall]

fix the black mold.

Yes - INSULATE!

 

[JohnD]

If you're going to tile it, and the plaster is bad, surely you could hack it off and use an insulated board of similar thickness.

 

[TheEnquirer]

@JohnD

I probably won’t retile it. I could hack it off but it’s seems more work then just filling the holes and plastering over it. I really don’t see the point.

Also these older houses need room to breath so im just looking at repairing the walls. The house gets very warm in each room and as heat rises it fairly energy efficient.decent loft insulation and bills seem reasonable.

When I install the new bathroom I will make sure that I have got a good, powerful extractor fan to counter the steamy showers!

Any idea on a good filler or do you recognise the type of wall it is? What material?

If not, no problem

 

[RrogerD]

@JohnD

I probably won’t retile it. I could hack it off but it’s seems more work then just filling the holes and plastering over it. I really don’t see the point.

Also these older houses need room to breath so im just looking at repairing the walls. The house gets very warm in each room and as heat rises it fairly energy efficient.decent loft insulation and bills seem reasonable.

When I install the new bathroom I will make sure that I have got a good, powerful extractor fan to counter the steamy showers!

Any idea on a good filler or do you recognise the type of wall it is? What material?

If not, no problem

Any idea on a good filler
If it was me and as I say, if the most part of it is solid then I'd hack off the mouldy surface areas, SBR to stabilise it all and then use bonding coat to bring it all back to level.

 

[TheEnquirer]

Oh I see, sorry I miss read what you were saying. Taking off the top layer where the mould is shouldn’t be too much work (famous last words.) ok I will do that, sbr then a bonding coat.

Thanks @RrogerD