Strange smell.....

[Zebra]

Now, this guess could be totally out, and feel free to laugh at me, but does anyone have any experience of sheepswool (thermafleece) insulation in a breathable wall structure, 10 years later?
I have a timber frame upstairs (brick downstairs) with thermafleece between the studs, woodfibre insulation and lime render on the outside, woodwool and lime plaster on the inside, totally breathable inside to out, and now, 10 years on, it's a bit......well there's definitely a musty sort of smell to the room, especially in summer. I don't think it's me, I've checked for dirty socks under the bed etc. There's no damp patches or cracks in the render that might be causing it to get wet but I just wonder whether the moisture moving through the walls might possibly cause the sheepswool to get a bit smelly? The smell is a bit like wet dog, a bit like armpits. It clears up with ventilation but it wasn't like that before and I'm wondering what it can be. I suppose a dead squirrel in the loft is possible but there's no trees nearby, it'd be a real leap for them to get up there? I've never heard the scrabbling around of rats or mice. And besides, that would fade over time. And I know what dead rats smell like, this is different. Like I say, I don't think it's me, but who knows, perhaps with lockdown standards of personal hygiene have dropped and I haven't noticed til now.

 

[Cubist]

Towards the end of last winter I noticed an offensive musty and vaguely sweet odour that seemed strongest in the master bedroom here - 16C black and white timber frame cottage. A couple of years before, I had levelled the ocean wave that had been the floor while installing replacement boards, and had been sensible enough to leave some access points to allow maintenance of the plumbing and electrics at strategic spots. These, together with my borescope, proved invaluable in my hunt for the source of the niff and I quickly discovered the corpse of a mouse lying on top of the central heating pipes that run under the floor. The cause of said mouses departure from this mortal coil was impossible to determine but must have been very recent as the central heating pipes on which its corpse rested had advanced the rate of decay to the point where its gut expanded explosively. :shock: The resulting pong being its innards gently broiling on the pipes.

After donning suitable PPE and gingerly removing the sprayed remains I decided it may be wise to take pre-emptive measures just in case the ex mouse had brought along some family and friends. To my surprise over the next couple of weeks I disposed of no less than ten of the little blighters that had either come in to get out of the cold or perhaps, more alarmingly, had bred in-situ :!:

 

[Zebra]

Thank you Cubist, I perhaps some further investigation is necessary....... I'll be reassured at least if it's not me that pongs.

 

[Cubist]

Thank you Cubist, I perhaps some further investigation is necessary....... I'll be reassured at least if it's not me that pongs.

And that reminds me. Some time ago the First Lady proposed some minor modifications to support/enforce her demand that, after long hot days toiling outdoors, my soiled and seriously perspiration soaked attire should be removed as I entered the house and the lot deposited in the washing machine before I padded off to the shower. With no obvious amorous intent it became clear that her motivation for this requisite was rooted in her olfactory nerves. Never having been at all self conscious I was not unhappy to comply but balked quite vociferously when she modified her requirements to include an outdoor shower next to my sheds - as these are 75 meters from the house and requires my crossing a bridleway, I was a trifle concerned about alarming the odd rambler or being accused of worrying the local sheep. :shock:

 

[worms]

Zebra, you are undoubtedly in a warmer and drier part of the country than me, but I wonder if it is just down to the fabric of the house being a lot more humid in summer (with no heating on) than it is in winter? We certainly struggle here with doors and windows swelling through the summer months when the heating is off, but returning to normal in autumn. An added problem is that the house can be cooler inside than outside, so warm moist air entering the house condenses on the cooler indoor walls. I wonder if the absorbent properties of the sheeps wool makes it more humid in summer, leading to the wet-dog smell?

Also, I guess a breathable wall is always at risk of interstitial condensation and this is managed by the normal passage of air and moisture from warm inside to cool outside. Could it be that this passage breaks down in summer and there is a dew point in the wool?

 

[a twig]

Just a thought - as long as the mustiness smell goes again - doesn't that mean the breathable wall is working?

 

[Zebra]

Zebra, you are undoubtedly in a warmer and drier part of the country than me, but I wonder if it is just down to the fabric of the house being a lot more humid in summer (with no heating on) than it is in winter? We certainly struggle here with doors and windows swelling through the summer months when the heating is off, but returning to normal in autumn. An added problem is that the house can be cooler inside than outside, so warm moist air entering the house condenses on the cooler indoor walls. I wonder if the absorbent properties of the sheeps wool makes it more humid in summer, leading to the wet-dog smell?

Also, I guess a breathable wall is always at risk of interstitial condensation and this is managed by the normal passage of air and moisture from warm inside to cool outside. Could it be that this passage breaks down in summer and there is a dew point in the wool?

Worms, I think you could be bang on there. Yes the house is cooler inside than outside at this time of year. Being low with small windows, and a little beneath ground level at the back, it often annoys me that I'm cold indoors when it's sunny and warm outside. So everything you suggest could be true - condensation on inside surfaces (though it's lime plaster and therefore doesn't show), humidity absorbed by the wall, and some sort of unanticipated dew point when it's warm outside. I very much appreciate your thoughts on it.

 

[Zebra]

she modified her requirements to include an outdoor shower next to my sheds

What were you doing, Cubist, that you became so revolting that you couldn't come within 75 metres of the house without a hosing down!?

 

[Zebra]

Just a thought - as long as the mustiness smell goes again - doesn't that mean the breathable wall is working?

Yes, haha, I suppose it is, if it's breathing a wet dog smell into my bedroom then I suppose it's working!

 

[CliffordPope]

That's the problem with a natural product - it has a natural smell!

It's obviously a good thing for walls to breathe through the outer face, but I've never been so sure about the point of internal breathing. Surely a one-way breathable membrane is what's needed?

 

[Cubist]

she modified her requirements to include an outdoor shower next to my sheds

What were you doing, Cubist, that you became so revolting that you couldn't come within 75 metres of the house without a hosing down!?

she modified her requirements to include an outdoor shower next to my sheds

What were you doing, Cubist, that you became so revolting that you couldn't come within 75 metres of the house without a hosing down!?

Ah.... When we finally came across this old place, at the end of a five year search, we unintentionally acquired somewhat more land than we intended. Yes, a largish garden was high on the First Ladies list but less so on mine. Finding that Fircroft came with three acres of predominantly hill-side divided into four fields with a public bridle-way running through it though did not deter us -maybe it should have done. Particularly as the previous owner claimed a strategy of 'wilding' to facilitate wild-life occupation for his admiration but bluntly I suspect sheer bone idleness! :roll: As a consequence the hedgerows had run amok and the fields, which had previously supported flocks of sheep, had become overgrown with bracken and bramble which had accumulated into drifts that in many areas extended to 50 square metres and up to 2.5 metres deep. :shock:

Being a rather 'tidy' and 'organised' person this state of affairs was anathema to me and, to be honest I was also intrigued to find out what was buried under all this foliage. Like a jungle explore but sans pith hemet, and with no clear idea of where I was trying to get to, initially I set out with a Fiskars bill-hook. Soon though, I realised I needed something with more muscle if I was going to do more than make a minor dent on the challenge. Hence my aquistition of a a petrol engined Brushcutter, think 'strimmer on steroids', equipped with a steel cutting blade that could easily cut through saplings of up to an inch in diameter.

Over the next couple of years I managed to clear the jungle and get the fields back to grazing/meadow but, given the predominantly steep terrain a means of keeping the bracken and bramble at bay whilst encouraging the grasses, the main attachment to the brush-cutter was swapped to the bump controlled nylon string line. This proved highly effective and I have become rather adept with this my only landscape gardening tool. However, there are some downsides to its use and not least that it can frighten nervous horses and decapitate unwary mice and frogs. Particularly notable though is its ability to catapult small pebbles and other hard objects in random directions and to surprising distances. As a consequence I have to be wary next to roads and footpaths and very careful indeed when clearing weeds from the gravel paths around the house. This also brings the threat of personal injury as even small pea gravel can do some painful damage and a pebble hitting the blade of your shin can really spoil your day.

But this only provides general background for the answer to your question. Whilst I would dispute a personal description of 'revolting' I would accept that the same could not be said of the protective kit and clothing I use when keeping the place tidy. Only the badger communities, of which we have at least two sets, are 'potty trained' and can be relied upon to habitually use latrines which they dig some distance from their sets. All the other animals, wild and strayed domestics, are less discerning and will leave their deposits anywhere they may. Consequently, when using my brushcutter, I have found it wise to watch for piles of scat that can, if attacked with a high speed string line, have a rather detrimental affect on ones self esteem and acceptability to others.

Being pelted with animal dung is not a pleasant experience at the best of times but can be much worse if one inadvertently wanders into an area of latrines frequently used by badgers as their diet produces the most offensive pong I have ever encountered.

 

[worms]

Cubist, I'm with you on the strimmer line issue. I attend to various bits of public land in an attempt to "do my bit" to keep the village tidy and while the vast majority of the village dogs seem to manage to poop in a bag, there are always a few that don't make it, or leave the bag where they think they will remember to pick it up again at the end of their walk. Strimming left to right helps to splatter everything away from the operator but even so, the clothes and myself need to go straight in the wash. Followed, of course, by suitable libations to take away that unmistakable taste...

 

[Cubist]

Cubist, I'm with you on the strimmer line issue. I attend to various bits of public land in an attempt to "do my bit" to keep the village tidy and while the vast majority of the village dogs seem to manage to poop in a bag, there are always a few that don't make it, or leave the bag where they think they will remember to pick it up again at the end of their walk. Strimming left to right helps to splatter everything away from the operator but even so, the clothes and myself need to go straight in the wash. Followed, of course, by suitable libations to take away that unmistakable taste...

Libations. Thats the word and perhaps the only thank you we get!

 

[Zebra]

Brilliant story cubist! Certainly answers my question.

I have however another theory about the whiff and suspect it's nothing to do with the insulation. Investigation ongoing....

 

[Cubist]

I think in one of your earlier posts you describe the niff as "wet dog'.

There is perhaps another line of investigation for your pursuit. The First Lady thoroughly despises carpets, particularly of the wall to wall fitted variety. My dislike of them is rather mild by comparison and I have sometimes wondered why she is so averse - could be consequential I suppose as she holds similar views concerning the vacuum cleaner. The reason I mention this is that that attitude, after moving in here, lead to my first job in the place which was; to evict with extreme prejudice all such floor coverings. This in turn lead directly to my next job which was to under-pin and make safe the stairs that near collapsed when the carpet was taken up - the handholding wood-worm did an excellent job for a few hours but I just did not trust their continuing good nature. :roll:

That aside, while lifting the various stair and room carpets I discovered enough dog and cat hair, to stuff a small mattress! :evil:

My guess is that this animal hair, if it absorbed moisture from the surrounding atmosphere and wood-work, would be more than capable of producing that 'doggy odour' mentioned.

 

[Zebra]

Brilliant, cubist... I love the image of woodworm holding hands! And I am with her ladyship in the dislike of carpets and vacuuming. All solid timber floors here, a swish round with the broom and done, and carbon neutral too. So not really any nooks for dog hair, and rarely any dogs, and I don't think any historic animal hair, since the whole place was gutted when I moved in......
No, I think the whiff has been located to a malfunctioning laundry process, therefore it was clothes and sheets etc all coming out smelling worse than they went in and the effect being concentrated in the bedroom where such things are kept being coincidental with the sheepswool insulation, nothing to do with the walls at all.

 

[a twig]

The best solution and a relief all round

 

[worms]

Good outcome, Zebra! Glad you found the source of the problem. The current trend to cool washes is good for the environment at the global level, but can be less so at the very local level! I find that an occasional 90C wash with vinegar keeps the washing machine from giving the laundry that stale smell, but even so, the clothes themselves need a 40C or 60C wash every so often, too.

 

[Cubist]

Hmmm..

After what I've been putting through our machine it may need something a little more aggressive than vinegar. Can you still buy caustic soda?

 

[LadyArowana]

Worms, I think you could be bang on there. Yes the house is cooler inside than outside at this time of year. Being low with small windows, and a little beneath ground level at the back, it often annoys me that I'm cold indoors when it's sunny and warm outside. So everything you suggest could be true - condensation on inside surfaces (though it's lime plaster and therefore doesn't show), humidity absorbed by the wall, and some sort of unanticipated dew point when it's warm outside. I very much appreciate your thoughts on it.

I bet you’re not annoyed about being cooler indoors today!