Condensation mould

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Hello gents,

Hope everybody has had a great xmas.

From what you said there is an obvious problem with the external render that is still causing a dampness problem, which is most probably not helping the situation. The internal sand and cement is masking the problem, making the wall colder. Mould and condensation are often confused by people as they think there the same thing, you don't need condensation for mould to form. Mould only needs sustained periods of high relative humidity (65%plus) to grow, condensation needs 100% rh. The boundary layer is always 5% higher than the middle of the room, did you measure the rh and dew point?
 
What about a cottage floor with no dpm. Concrete underneath the laminate flooring is always wet. Should it be dug up and insulation and dpm put down
 
D4mp said:
Hello gents,

Hope everybody has had a great xmas.

From what you said there is an obvious problem with the external render that is still causing a dampness problem, which is most probably not helping the situation. The internal sand and cement is masking the problem, making the wall colder. Mould and condensation are often confused by people as they think there the same thing, you don't need condensation for mould to form. Mould only needs sustained periods of high relative humidity (65%plus) to grow, condensation needs 100% rh. The boundary layer is always 5% higher than the middle of the room, did you measure the rh and dew point?
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Yes, that's what I'm saying, render is a 'cold spot' attracting mould, which in this case won't really be helped by ventilation or dehumidifier s. The blown render/ pebble dash (both) on the outside does not help things. I don't need to measure RH as I know what's causing the problem from years doing this work.
I know the solution is to re do externals and put thermal board internally but moving rads, elec sockets, re papering, external rendering will run into £5k + and he's an old boy.
My cheap and cheerful solution would anti mould detol plus occaisional heat in damp area.
Cheers D4mp, I think we're both singing from the same hymn sheet :RpS_thumbup:

any my additional tips much appreciated please d4mp

p.s. Ignore the clown
 
cooptaza said:
What about a cottage floor with no dpm. Concrete underneath the laminate flooring is always wet. Should it be dug up and insulation and dpm put down
Click to expand...

Liquid dpm is a possibility if you have a dpc in the wall to get continuity, if not dpm and new concrete floor might be the only answer.
 
irish_spread said:
Yes, that's what I'm saying, render is a 'cold spot' attracting mould, which in this case won't really be helped by ventilation or dehumidifier s. The blown render/ pebble dash (both) on the outside does not help things. I don't need to measure RH as I know what's causing the problem from years doing this work.
I know the solution is to re do externals and put thermal board internally but moving rads, elec sockets, re papering, external rendering will run into £5k + and he's an old boy.
My cheap and cheerful solution would anti mould detol plus occaisional heat in damp area.
Cheers D4mp, I think we're both singing from the same hymn sheet :RpS_thumbup:

any my additional tips much appreciated please d4mp

p.s. Ignore the clown
Click to expand...

Cost will always come into the situation i'm afraid. Data is king when working out what is going on, perhaps I could send you a data logger this will tell you if its an internal rh problem, bedroom temps should be around 18 degrees. As the temperature drops the rh rises and then thats where the problems start. The rh normally rises in a bedroom around 2-3 am, this is when I have found them mould and condensation problems.
 
irish_spread said:
Did a bit of damp proofing for an old boy last summer in a sitting room and he called me back to do another couple of patches in a bedroom couple of weeks ago. Solid wall bungalow, rendered with s/c and sov rendermix. Cured the penetrating damp but now he's got condensation mould at low level in corners of the room.
Obviously this is caused by warm air condensation get on cold s/c areas ive done. Double glazed windows, no vents but claims he keeps the room warm and opens windows and I believe him.

Thing is, he's re papered and now got 'black dots' on paper and I know he can't afford d+d with thermal board. I don't think in this case a vent will help. Any recommendations for a cheap fix, I don't want him getting stitched up by a remedial damp co ?

Cheers
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Go to the £ shop (the good ones:RpS_sneaky:) they sell these condensation thingys ,plastic tub about the size of your hand,place em near where the mould is, sorted , as long as you clean the mould off that's already there , these little beauties will solve your problem.
ive used em and they are fantastic
 
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Cheers D4mp. I've solved his penetrating damp prob, it's in his sitting room but I'm not getting paid for the mould problem. I'm giving him free advice :RpS_mad:
 
superspread said:
Go to the £ shop (the good ones:RpS_sneaky:) they sell these condensation thingys ,plastic tub about the size of your hand,place em near where the mould is, sorted , as long as you clean the mould off that's already there , these little beauties will solve your problem
Click to expand...


Do do they really work ? :RpS_w00t:
 
irish_spread said:
D4mp , for £400 I can send one of my boys to cure all your mould.
:RpS_lol::RpS_lol:,u won't be larfing when u try these,digging up floors and checking rh levels do me a favour, I had the problem on the 2nd floor flat I rent out,didn't know damp can rise 50ft:RpS_laugh:
Click to expand...
 
D4mp said:
Liquid dpm is a possibility if you have a dpc in the wall to get continuity, if not dpm and new concrete floor might be the only answer.
Click to expand...

All walls are sealed with 50mm insulation board. Liquid dpm. Would it be ok without insulation underneath the floor
 
cooptaza said:
All walls are sealed with 50mm insulation board. Liquid dpm. Would it be ok without insulation underneath the floor
Click to expand...

You need to sprinkle some special salt om it cooptaza which you won't get in Superquinn in Donegal. It's £600 incl delivery
 
This is from a survey where there has been a problem for a while now on a social housing property, all the previous surveyors got it wrong.
 
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