Mould and cracks

s7ryf3925pivug

I just bought a house. I pulled out a fitted wardrobe. I found big cracks and a lot of black mould.

It has brick cabity walls with skim plaster interior walls and external insulation. The walls are both exterior walls and therefore load-bearing as I understand it. The house was built in the 70s.

I got a homebuyers report. The walls were tested for damp and all were fine. The interior walls were reported to be in excellent condition. Dont see any problems wiyh other walls.

Weirdly there is a vent on the outside of the wall but no vent on the inside.

Obviously it needs to be replastered, but how do I know or find out if there are other issues, or who do I get to look at it. I'll contact the surveyor and hopefully he'll respond helpfully and not defensively.

Calahonda52

is it damp?
any chance of a wider angle shot showing floor to ceiling
whats the black stuff?
You sure about the EWI... just checking

s7ryf3925pivug

This shot shows more context.

Yes definitely ewi, but it was put on fairly recently. 100mm. It was described on a house buyers report.

The black stuff is mould.

Definitely damp. If the cracks are a result of that damp then that's the best case scenario I think. It looks like they are along mortar in bricks behind the plaster though. I'm concerned it mighe be a significant structural defect... From googling it looks like settlement cracks.

dusteeroads

I think that you are suffering mould only to those places where air could not circulate before - behind fitted furniture.
The surveyor is likely to have taken many damp meter readings and as you say - found none so likely isolated to these places.
Clean it up and wait a month before taking readings ( hire a damp meter) . Hopefully you will find no remaining damp then.

Metric Tensor

Is that an upper external corner of a bedroom? If so I'd put my money on either an existing cold bridge or a cold bridge that has now been removed by the new insulation measures.

The moisture in the air is increased by people sleeping in the room overnight and it will condense on any cold spots in the wall - this would be further exacerbated by a lack of air flow past that region because of the fitted furniture.

dusteeroads is spot on in his recommendation above. Clean it up, treat the wall with an anti-fungal spray and leave it exposed for the winter. This is assuming the bedroom is currently in use. If not there is no point doing this test until it is next occupied.

s7ryf3925pivug

Thanks. Condensation there would seem likely.

Do you think the cracks are likely to be caused by the damp then, as opposed to indicating a structural defect?

dusteeroads

No one can see online for definite - but the cracks are probably cosmetic.

Try drawing penciled on X's across the cracks and observe over 3 months ( or more if you can ).
What you are hoping to see is that the Xs don't pull apart in any direction.

BryanF

Is this the corner of a hipped Roof ? If so there may be a lack of insulation where the rafters are cut in the corner.

s7ryf3925pivug

BryanF wrote: »

Is this the corner of a hipped Roof ? If so there may be a lack of insulation where the rafters are cut in the corner.

Yes it is. Thanks, I’ll check that out.

Calahonda52

Addisyn Flabby Transition wrote: »

Yes it is. Thanks, I’ll check that out.

Where did the EWI stop?
If it stopped at the soffit board, then the problem will persist:
the issue BryanF is referring to is aggravated by the cold air coming up through the ( I am assuming ventilated) soffit and chilling the uninsulated ceiling plaster board.

The only way to sort this out properly, from an insulation perspective, is from outside.
Strip off the bottom few rows of tiles and the ridge tiles on the hip.
remove the felt.
bring ceiling insulation out to meet EWI, or visa versa: I normally use well fitted rigid here
fit ventilation baffles on top of the rigid.
replace felt etc

This, on a two sorry house is neither cheap nor easy.
It cannot be done from inside.

s7ryf3925pivug

Calahonda52 wrote: »

Where did the EWI stop?
If it stopped at the soffit board, then the problem will persist:
the issue BryanF is referring to is aggravated by the cold air coming up through the ( I am assuming ventilated) soffit and chilling the uninsulated ceiling plaster board.

The only way to sort this out properly, from an insulation perspective, is from outside.
Strip off the bottom few rows of tiles and the ridge tiles on the hip.
remove the felt.
bring ceiling insulation out to meet EWI, or visa versa: I normally use well fitted rigid here
fit ventilation baffles on top of the rigid.
replace felt etc

This, on a two sorry house is neither cheap nor easy.
It cannot be done from inside.

Thanks I'll have a look at the ewi when I'm there but I think it stops at the roof. It's a single storey house. What sort of cost would you be talking about to get this done?

Who do you ask to do it too, actually? A roofer?

Will it be obvious to me where the ewi stops by looking at it, or how do I tell that?

Calahonda52

Addisyn Flabby Transition wrote: »

Thanks I'll have a look at the ewi when I'm there but I think it stops at the roof. It's a single storey house. What sort of cost would you be talking about to get this done?

Who do you ask to do it too, actually? A roofer?

Will it be obvious to me where the ewi stops by looking at it, or how do I tell that?

Glad to give some ideas: take some pictures from outside.
A builder who knows what to do is enough here, not a specialist roofer.
I would suggest you source some small pieces of rigid insulation, a ventilation baffle,[VB] and make up a model of what needs doing.

we can help you with the details here: the VB must be sealed to the two ceiling rafters and also to the rigid.
The VBs will need to be custom cut to fit the angles of the hip

dusteeroads

Addisyn Flabby Transition wrote: »

Thanks I'll have a look at the ewi when I'm there but I think it stops at the roof. It's a single storey house. What sort of cost would you be talking about to get this done?

Who do you ask to do it too, actually? A roofer?

Will it be obvious to me where the ewi stops by looking at it, or how do I tell that?

Wait and see before over reacting. Looking at the extent and intensity pattern of the of staining in your 4th photo - I think the problem is localized and with the removal of the fitted wardrobe - solved.

s7ryf3925pivug

Calahonda52 wrote: »

Glad to give some ideas: take some pictures from outside.
A builder who knows what to do is enough here, not a specialist roofer.
I would suggest you source some small pieces of rigid insulation, a ventilation baffle,[VB] and make up a model of what needs doing.

we can help you with the details here: the VB must be sealed to the two ceiling rafters and also to the rigid.
The VBs will need to be custom cut to fit the angles of the hip

Cool, thanks. I've attached some outside pics. It looks like the part of the roof it connects to was probably put there along with the EWI. It has vents in it.

Calahonda52

Addisyn Flabby Transition wrote: »

Cool, thanks. I've attached some outside pics. It looks like the part of the roof it connects to was probably put there along with the EWI. It has vents in it.

Thanks.
EWI stops at the soffit board.
I can't tell if there are vents in the soffit board

s7ryf3925pivug

Calahonda52 wrote: »

Thanks.
EWI stops at the soffit board.
I can't tell if there are vents in the soffit board

Yes there are vents in the soffit board.

Calahonda52

Addisyn Flabby Transition wrote: »

Yes there are vents in the soffit board.

Okay, so my theory is not dead, yet:D
depending on access via the attic, what I use for looking at these issues is a small cctv camera on a telescopic boom hooked up to a hand held display:
it's home made but works.
See attached from down near the corner in a hipped roof.
Ceiling underneath was black
This was 20 feet away from the attic hatch, past all the suitcases and Xmas deco's:D

s7ryf3925pivug

Calahonda52 wrote: »

Okay, so my theory is not dead, yet:D
depending on access via the attic, what I use for looking at these issues is a small cctv camera on a telescopic boom hooked up to a hand held display:
it's home made but works.
See attached from down near the corner in a hipped roof.
Ceiling underneath was black
This was 20 feet away from the attic hatch, past all the suitcases and Xmas deco's:D

Thanks, I see what you mean. Attic is empty but it will be very hard to check this as it is low and has no boards, and the corner is very far from the hatch.

The previous owners left rolls of insulation in a shed in addition to what is already laid, and also two pieces of hard insulation. Might this be suitable for the purposes you described?

s7ryf3925pivug

Gap in the insulation above the mould square. Weird; same in another corner too. So easy to fix.

Crack in opposite corner also right down corner itself and a long way across the ceiling. Is this a concern? It is narrow.

Cleaned the bad corner with fungicide and removed the skim plaster where it was lifting off the wall. Cracks are in the concrete underneath as well. All cracks are pretty narrow, 2mm max I think.

s7ryf3925pivug

Hired plasterer to replaster and repair cracks about a month ago. Noticed this morning bubbles and dimples in the plaster on the wall with the window. Am I right in thinking this indicates water is coming through that crack? The ceiling looks fine.