Damp smell, humidity in apt. Cracked render.

A

Annakay

Registered User
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Hi,

I live in a one bed apartment. I had a piv unit installed a year ago. It has helped with the high humidy issue. It brought it down from 80% to 45% - 60%, depending on the time of year. The damp smell in the apt. and on clothes improved a lot, but it's still not right.

There is still a musty smell from clothes that are left on a chair in the bedroom or on the couch. Basically if they are in the air and not tightly closed away in drawers, they smell. Even the top layer of clothes in the hot press have a smell of damp to them.

I had two surveyors look at the apartment in the previous years. They checked walls for damp. They didn't find any. I have interior insulation so maybe that is hiding something.

Even when I'm not there the humidy could read 55% - 60%. I have heating on a timer, so it's never cold. I wonder is this normal.

There are two cracks in the exterior walls. They were never flagged as an issue. Just the internal humidity being the problem. Now I'm wondering if there is water ingress from them. I don't have damp patches though.

One hairline crack from roof to ground on north facing wall. Interior insulation behind this.

Other crack more significant, roof to ground on east facing wall. Interior insulation on the top part after bathroom renovation, no insulation on bottom part due to it being the kitchen. No damp patch in kitchen.

Is it worth getting these fixed by the management company or is it just an internal issue.

Any advice welcome. Thank you.
 
Apartments can have better or worse insulation but mould depends more on the habits of the occupant.

My own house has tendencies toward mould but you can really reduce it by taking a few measures.


Do the following:
  • Wipe down shower panels and tiles with a squeegee after a shower. This reduces a huge amount of moisture that otherwise evaporates and tends to accumulate on cold surfaces which can lead to mould
  • Open windows as much as possible
  • Wipe down condensation on windows every morning.
  • Don't overstuff your wardrobes - air needs to circulate around clothes
  • Scrape areas of wall and ceiling where mould accumulates, wash it with a chlorine-based cleaner, and repaint with an anti-mould paint
  • Buy a desiccant dehumidifier (they are small and quiet) and run in the room where mould accumulates
  • It should be obvious but drying clothes indoors is likely to lead to mould. Try to avoid if possible and if you can't run a dehumidifier in the room at the same time

In my view wall vents aren't hugely important but check that they are not blocked up. Likewise heating helps but keeping ambient humidity low via the above is more important.
 
Rather than the desiccant humidifier, try a condensing one.

Meaco is a good brand & with a piece of hose pipe you can let it drain & not have to empty it.

They are pennies to run.

Raise the external cracks to your management company. Are the other residents having issues?
 
DannyBoyD said:
Rather than the desiccant humidifier, try a condensing one.

Meaco is a good brand & with a piece of hose pipe you can let it drain & not have to empty it.

They are pennies to run.

Raise the external cracks to your management company. Are the other residents having issues?
Click to expand...
Thank you. Yes I have a meaco running all the time. It's full every 24hrs. It's a 12ltr one.

The neighbour beside me on the ground floor says his clothes smell of damp. He now has to bag them up to keep them fresh. I didn't smell damp when I was in his place. But he is someone who rarely puts his heating on.. extremely frugal. He's old. So I don't know if the damp is to do with the crack in the wall between us or his living conditions.

The neighbour above him doesn't have an issue. His apartment is also bedside the cracked render.

What I cannot understand is my family home has a similar humidity reading to my place. There has never been damp there or any smells, or musty clothes.
So if the humidity reading is the same in both places, why does my apartment smell damp and everything that comes out of it has a musty smell.
 
@Annakay, can you describe the type of internal insulation you have (e.g. insulated plasterboard or insulation between battens with plasterboards skim finish ...) and when was it installed. What age is the apartment building and what type are the external walls (e.g. solid block or cavity or ?).
Also, you mention the kitchen wall being both uninsulated internally and damp free, is this an external wall?
 
Micks'r said:
@Annakay, can you describe the type of internal insulation you have (e.g. insulated plasterboard or insulation between battens with plasterboards skim finish ...) and when was it installed. What age is the apartment building and what type are the external walls (e.g. solid block or cavity or ?).
Also, you mention the kitchen wall being both uninsulated internally and damp free, is this an external wall?
Click to expand...
Insulated plasterboard.. It was done before I moved in. I'm there 5 yrs so I'd say it was done within the last 10 yrs.

Cavity walls. Build 1960.

The front wall is external where the sink is and window is . Then the right side is adjoining the neighbour.
 
Annakay said:
Insulated plasterboard.. It was done before I moved in. I'm there 5 yrs so I'd say it was done within the last 10 yrs.

Cavity walls. Build 1960.

The front wall is external where the sink is and window is . Then the right side is adjoining the neighbour.
Click to expand...
To summarise what we know, you are getting a musty / damp smell yet no visible signs of damp or mould. The external walls are cavity walls (pumped?, what size cavity? - 1960 was early doors for cavity wall construction!) and internally drylined/insulated with insulated plasterboard. You heat the place sufficiently and open the windows regularly. You have had a PIV unit installed which has had a positive impact on the RH% readings but not the musty smell.

In my experience, what you are experiencing are the classic symptoms of interstitial condensation occurring between the original internal wall surface and the back of the insulated plasterboard. This condensation then becomes a constant water source for mould to grow & thrive there and this is what you are smelling.

This phenomenon would generally be more prevalent on the North & East side of a building.

The PIV unit may not be helping as much as you might think in that it may be forcing moisture laden relatively warm air through gaps etc in the drylining (there are many), not really helping the issue (this is the risk with PIV over a central extract system!).

I doubt the crack in the external render is in play because of the cavity, though it should be dealt with by the management company in any case.

Possible actions to consider:
  1. Ensure there are no active water leaks in the building
  2. Did any of the surveyors open up a socket or switch and see / smell what is behind on the wall (obviously isolating the power first)? If not, this would be my first action in the worst affected room. Take action depending on findings.
  3. Can the wall cavity be insulated?
  4. Consider upgrading / changing the ventilation to a continuous central mechanical ventilation system to remove the moisture at source.
 
It would depend during which season this is happening .... it might well be possible for 12l in 24hrs in the warmer months in the absense of a water ingress issue / leak.
If, on the other-hand, it is during the colder months with the heating on then I agree, something's amiss.
 
Micks'r said:
To summarise what we know, you are getting a musty / damp smell yet no visible signs of damp or mould. The external walls are cavity walls (pumped?, what size cavity? - 1960 was early doors for cavity wall construction!) and internally drylined/insulated with insulated plasterboard. You heat the place sufficiently and open the windows regularly. You have had a PIV unit installed which has had a positive impact on the RH% readings but not the musty smell.

In my experience, what you are experiencing are the classic symptoms of interstitial condensation occurring between the original internal wall surface and the back of the insulated plasterboard. This condensation then becomes a constant water source for mould to grow & thrive there and this is what you are smelling.

This phenomenon would generally be more prevalent on the North & East side of a building.

The PIV unit may not be helping as much as you might think in that it may be forcing moisture laden relatively warm air through gaps etc in the drylining (there are many), not really helping the issue (this is the risk with PIV over a central extract system!).

I doubt the crack in the external render is in play because of the cavity, though it should be dealt with by the management company in any case.

Possible actions to consider:
  1. Ensure there are no active water leaks in the building
  2. Did any of the surveyors open up a socket or switch and see / smell what is behind on the wall (obviously isolating the power first)? If not, this would be my first action in the worst affected room. Take action depending on findings.
  3. Can the wall cavity be insulated?
  4. Consider upgrading / changing the ventilation to a continuous central mechanical ventilation system to remove the moisture at source.
Click to expand...
Thank you so much for your time and advice.

I've been thinking that very thing, about mould being behind the insulation.

Yes it's block cavity walls. Not pumped.

No he didn't check behind sockets.
He did put a hole in the interior wall, east facing, because I wanted to see if there was mould there behind the insulation. There wasn't in that spot. But maybe there is elsewhere. Especially the gable wall, north facing, . He wouldn't put a hole there because it was too obvious a place to repair, the entrance hall, so he did behind the door of the sitting room instead.
I've had the bathroom and kitchen done, no leaks there.
And the flooring downstairs replaced. No signs there of anything.

He insisted it was just humidity from too much insulation and not enough ventilation.
 
Annakay said:
All windows are opened for 30 mins in morning. And I leave the bathroom window open an inch most of the day and night.
Click to expand...
Am I the only one who feels this is way too inadequate, especially given your extensive condensation ? Is the apartment dual aspect ? I open mine all day and it takes about 2 hours to clear the bedroom fully.
 
elcato said:
Am I the only one who feels this is way too inadequate, especially given your extensive condensation ? Is the apartment dual aspect ? I open mine all day and it takes about 2 hours to clear the bedroom fully.
Click to expand...
Like most things in life, it depends.
The no.1 decider whether a ventilation strategy is efficient (and efficient means in this instance, the rate of removal of moisture) is the internal / external air temperature difference. Opening all windows all day when there is minimal temperature difference will do little to remove moisture yet opening for 60 mins when there is a large temperature difference (>20 degC say) can do wonders.
This is why getting ventilation right is tricky in our mild and temperate climate ....
 
Micks'r said:
In my experience, what you are experiencing are the classic symptoms of interstitial condensation occurring between the original internal wall surface and the back of the insulated plasterboard. This condensation then becomes a constant water source for mould to grow & thrive there and this is what you are smelling.
Click to expand...

This reminds me of an episode from Room To Improve *, where there was a damp smell, and when they pulled down the internal wall insulation to see any possible cause, there was a huge mould growth behind it...

* for reference only - any discussions on the show itself should not be discussed here :D
 
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