Author Topic: Damp, again (the saga continues)  (Read 1656 times)

valkyrie

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Re: Damp, again (the saga continues)
« Reply #25 on: February 16, 2021, 08:34:31 pm »
It looks to me like that opening was originally made for a pipe. Maybe an old boiler flue or drainpipe connection? Whatever it was for, it’s clearly just a cold bridge now. I’d bit the bullet and pay for a man with a ladder to remove the vent, fill the hole with expanding foam and then brick it up. If fitting a stone or brick to close the hole is tricky then you could use something like a soot door cover instead.
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ian

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Re: Damp, again (the saga continues)
« Reply #26 on: February 16, 2021, 08:40:44 pm »
We had a proper damp surveyor for this place (we pulled out the kitchen, and groo) and that was down to cold walls, moisture, limited airflow around the back of appliances, and the fact the dishwasher had been leaking slowly like an old, drunk uncle into the corner for years. Once we'd cleaned up after the incontinent dishwasher (or rather paid someone to do it), he recommended tiling the walls behind the units (so moisture can't soak in), making sure there was space for airflow, and keeping the kitchen warm.

Basically, any significant temperature gradient will condense ambient moisture, but mould requires permanent moisture ~75% or higher – so a surface that is wet more than it is dry.
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Mrs Pingu

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Re: Damp, again (the saga continues)
« Reply #27 on: February 16, 2021, 08:55:03 pm »

Can you not install a panel radiator on that wall to heat the wall and cover up the mould. That's what I'd do.
Hmm, could do I suppose. If we haven't managed to offload this place before autumn (which I have an unhappy suspicion may transpire) maybe I'll give my plumber a shout.
Do not clench. It only makes it worse.

Aunt Maud

  • Le Flâneur.
Re: Damp, again (the saga continues)
« Reply #28 on: February 17, 2021, 07:13:45 am »

Basically, any significant temperature gradient will condense ambient moisture, but mould requires permanent moisture ~75% or higher – so a surface that is wet more than it is dry.

I'd be surprised if it's rain doing it, as it needs to get through the vent, along the tunnel and hit the wall. Unless there's a puddle forming, but then the carpet would be wet.

You could close most of the vent up and live a smaller hole for the air to get in.

Mrs Pingu

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Re: Damp, again (the saga continues)
« Reply #29 on: February 17, 2021, 12:37:23 pm »
Ok, if I was to squirt a load of expanding foam in there but leave a wee slot at the top would that not still leave me with the same cold bridging issue?

I take it when you said put a panel radiator on the wall you meant a GCH one, not an electric?
Do not clench. It only makes it worse.

Aunt Maud

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Re: Damp, again (the saga continues)
« Reply #30 on: February 17, 2021, 04:39:43 pm »
Something like that.

Any radiator would do, but if you've got gas and its cheaper then that would be the one I would use.

The radiator would heat the wall and dry it out, plus create convection currents and increase the airflow over that part of the wall. Mould loves still air, which is why it's first found in corners of ceilings or at the bottom of walls behind furniture.

In the meantime, you could wipe it off with a cloth to reduce the number of fruiting bodies which produce spores. Just wipe it off with a dry paper towel and keep at it on a regular basis. It should keep it at bay for the meantime.

Mrs Pingu

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Re: Damp, again (the saga continues)
« Reply #31 on: February 17, 2021, 05:00:55 pm »
Cool. I've got some fungicidal stuff (Granocryl) coming this weekend which will help a bit, hopefully, and I've spied somewhere that will hire and deliver a decent ladder so that can be a job when I'm off in a couple of weeks. In the meantime I just need to persuade Pingu to move the hifi stand a bit so I can get in at the wall...
Do not clench. It only makes it worse.

Aunt Maud

  • Le Flâneur.
Re: Damp, again (the saga continues)
« Reply #32 on: February 17, 2021, 05:15:21 pm »
It's a horrid thing.

We had it in our place in Somerset after I installed double glazing. It went ballistic and the only way I could get rid of it was to sell it to someone else with the house still attached.

Mrs Pingu

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Re: Damp, again (the saga continues)
« Reply #33 on: February 17, 2021, 05:40:51 pm »
Aw don't tell me that.
Do not clench. It only makes it worse.

ian

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Re: Damp, again (the saga continues)
« Reply #34 on: February 17, 2021, 05:46:36 pm »
Give it a good wipe down with a fungicide (benzalkonium chloride or similar).
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Mrs Pingu

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Re: Damp, again (the saga continues)
« Reply #35 on: February 17, 2021, 06:12:56 pm »
That's what's in that Granocryl stuff.
Do not clench. It only makes it worse.

Re: Damp, again (the saga continues)
« Reply #36 on: February 17, 2021, 10:03:18 pm »
I hope this helps.

We live 10 miles S of PHD and this has been the wettest winter we remember in 40+ years. So not so different in ABZ.

A flat roof leak I thought I had cured 20 years ago has reappeared although it  seems OK now with (at last)  improving weather.

Your problem could just be the weather, which is my excuse for doing nothing.

Aunt Maud

  • Le Flâneur.
Re: Damp, again (the saga continues)
« Reply #37 on: February 18, 2021, 01:12:50 pm »
Benzalkonium chloride is toxic to cats, mind.

ian

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Re: Damp, again (the saga continues)
« Reply #38 on: February 18, 2021, 03:37:33 pm »
Everything is toxic to cats. Even mild criticism. Fortunately, they don't often lick walls unless you treat them with tuna first.
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Mrs Pingu

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Re: Damp, again (the saga continues)
« Reply #39 on: February 18, 2021, 05:13:00 pm »
Yes. Benzalkonium chloride is probably toxic to everything too. I shall endeavour only to make up a small amount in the hope I remember not to pour it down the drain afterwards...
Do not clench. It only makes it worse.

hellymedic

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Re: Damp, again (the saga continues)
« Reply #40 on: February 18, 2021, 06:19:34 pm »
That might be an over-reaction, given how commonplace benzalkonium is in Dettol, hand sanitiser and zillions of other cleaning products.

ian

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Re: Damp, again (the saga continues)
« Reply #41 on: February 18, 2021, 06:26:01 pm »
It's relatively common in medical preservatives, though they seem to be phasing it out, probably because they can rely on sterilization and hyperfiltration. It has also disappeared, much to my annoyance, from the Waitrose Daily Shower Shine.
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Aunt Maud

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Re: Damp, again (the saga continues)
« Reply #42 on: February 19, 2021, 07:10:39 am »
You may see it as a mild over reaction HM, but it's still a truefact™ and worth being aware of.

Re: Damp, again (the saga continues)
« Reply #43 on: February 19, 2021, 07:28:54 am »
Here in France they recommand spirit vinegar to remove mould from walls rather than bleach. You can buy it for such in DIY and hypermachés on the hardware/cleaning departments.

ian

  • feat. Undead Jess & Finestre, Queen of Hell
Re: Damp, again (the saga continues)
« Reply #44 on: February 19, 2021, 09:53:33 am »
Killing mould is quite difficult, the spores are Hard to Kill without stathaming them with proper chemicals. They will laugh at vinegar and, quite possibly, the French.

Any damp surface will get re-infected, mould spores are environmentally ubiquitous, you're breathing them in with every breath.

So basically, however you kill what's currently on the surface, if it stays damp it will be reinfected.
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Mrs Pingu

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Re: Damp, again (the saga continues)
« Reply #45 on: February 19, 2021, 12:36:30 pm »
Here in France they recommand spirit vinegar to remove mould from walls rather than bleach. You can buy it for such in DIY and hypermachés on the hardware/cleaning departments.
I had seen that. What I read was that it actually kills it, as opposed to bleach which just makes the black go away....
Do not clench. It only makes it worse.

hellymedic

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Re: Damp, again (the saga continues)
« Reply #46 on: February 19, 2021, 02:43:26 pm »
I used copper sulphate from a sibling's chemistry set to kill mould on my Pedersen saddle.
Seemed to do the trick.
Moulds don't like Cu++!

Mrs Pingu

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Re: Damp, again (the saga continues)
« Reply #47 on: February 19, 2021, 03:59:50 pm »
Of course my lovely lime plaster probably won't appreciate me dissolving it with acetic acid. Anyway the Granocryl has arrived.
Do not clench. It only makes it worse.

ian

  • feat. Undead Jess & Finestre, Queen of Hell
Re: Damp, again (the saga continues)
« Reply #48 on: February 19, 2021, 04:30:35 pm »
Basically, you won't kill mould spores as they're chitinized little motherfuckers, and if you did, more would simply land there. So basically it's a case of removing the conditions for them to germinate (removing the moisture) or putting something there that prevents germination or kills them if they do. The only full-time solution is the former, wet surfaces will always eventually turn mouldy.
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Re: Damp, again (the saga continues)
« Reply #49 on: February 20, 2021, 07:18:24 am »
Regarding lime plaster, do note that if the surface is appropriately base (I think pH > 11 or so), mold (mould) can't propagate.  There are some "lime paint" products (at least over in USAnia) that do their mold-proofing work on that basis.
Bleach just takes the black away.  Does not kill the stuff.
Reducing humidity is another solution, as is making sure there is no cellulose about.