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So apart from Piglet John who in real life do you go to for advice on condensation?

50 replies

Indith · 05/01/2014 13:42

That's the question really!

Who in real life deals with this, knows their stuff and can help pinpoint the problem without an agenda to sell you something?

I know I'm going to need to buy something/do something/change something but I want to get it right and solve the issue at cause rather than deal with the consequences as it were.

So are there people whose job it is to do that? Any googling just leads me to people selling expensive whole house mechanical extraction and heat exchange units. Which to be fair is probably not that far off the mark with this house!

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Indith · 05/01/2014 17:04

.

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KatyMac · 05/01/2014 17:07

My dad? Structural engineer with loads of housing experience...... he wouldn't do it 'professionally tho'

but Pigletjohn might be better Wink

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PigletJohn · 05/01/2014 17:56

Are you looking for someone who won't say "ventilate more and don't drape wet washing around?"

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noisytoys · 05/01/2014 18:00

PigletJohn is an encyclopaedia of damp and house things why would you look for anyone else?

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MaudLebowski · 05/01/2014 18:08

You might ask someone like me, I'm a construction consultant. You'd still get the same answer as Pigletjohn gave though, condensation is a bit of a pain, but how it works is actually really simple so It's a. make the air less moist followed by b. ventilate more. If you were desperate to throw money at the situation I might suggest mechanical ventilation or trying to warm your building fabric up by say external insulation or very efficient windows, but you'd be talking a lot of money unfortunately, and that sneaky moist air would still be looking for the next coldest place to settle.

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Indith · 05/01/2014 18:20

Grin no I'm not looking for someone to tell me it is ok to drape washing around. But I have extractor fans in kitchen and bathroom, my house is kept at constant temp as is solid fuel heated so no peaks and troughs of temp. I ventilate daily but my dds room in loft had some patches that get soaked. I wipe dry and open windows first thing. By lunchtime it is wet again. I can't stay on top of mould. even her duvet feels damp.i cried when i realised that. my daughter sleeps everynight ina duvet that gets damp from condensation. wonder if i need a real life person who might be able to pinpoint something that I can't, that a person online can't.

If there isn't, fine. But how can I create less moisture? use fans, bathroom door closed etc. washing dried outside when ican though of coursethat ishard in winter. humidity thingy says around 55% downstairs. bathroom is downstairs too. Don't get me started on the constant wet down there. I think that is just old, cheaply built extension. dint think I can get rid of that. But dd's room is at 75 to 85%. I'm frankly lost.

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MaudLebowski · 05/01/2014 18:30

Whereabouts are the patches in the loft that get soaked?
The loft will probably be the worst because the hot moist air floats upward through the whole house and then meets the loft ceiling which, if its an old house, will have no insulation whatsoever and be very old.
Can you keep the attic door closed and the attic windows open as an experiment? It should reduce the humidity in the room and thus the condensation.

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Indith · 05/01/2014 18:35

It is a little alcove where the fire escape is plus a patch on a wall adjacent to an unoccupied house. We redid the insulation when we split it to create an extra room. It is colder up there which I know won't help.

How long would you day you'd have to keep windows open and door closed for? I do that for a bit daily but if I did it all day dds room would be freezing for her to go to bed in.

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Dromedary · 05/01/2014 18:41

Based on his posts I would guess that PigletJohn sells or installs glass fibre insulation, which by the way is widely considered to be a cancer risk (lung cancer), so watch out for that. When sold in the US it has to have a cancer warning on it.

We have damp problems also. Installing more insulation and double glazing can apparently make things worse, as it impedes ventilation. We use a humidifier, which is pretty effective, especially if you only have one problem room which seems to be the case for you. It basically sucks the water out of the air and into a plastic cannister, which you then empty out of the window once every couple of days.

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MaudLebowski · 05/01/2014 18:43

Window open for an hour or so, but leave the door shut all day and see if its better by the evening, that will show if its the moisture from the rest of the house causing it.
The moisture in the alcove sounds more leaky than condensation. Try sticking a bit of plastic on it with duct tape all the way round and see if the moisture seems to be on the face of it or underneath after a few days.
A sleeping person generates a surprisingly large amount of water, it might be worth having your dd sleep elsewhere for a couple of days and see if that makes any difference too.

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PigletJohn · 05/01/2014 18:47

I would guess that PigletJohn sells or installs glass fibre insulation

absolutely wrong!

I would be interested to see any reputable research about health effects. It has been in wide use in the UK for over 50 years so there should be plenty of evidence by now.

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Indith · 05/01/2014 18:52

Ok, good tips. Shall investigate! As far as I know the roof is fine, has a roofer up not that long ago doing the ridge but I'll have a play. Not really anywhere else for dd to sleep other than the adjoining room. Not sure how much difference that would make.

drom I know, I need to get a balance between ventilation and insulation. I do mind of need to see if we can insulate more as it is cold up there. Have ordered a dehumidifier to try to dry it out and keep on top of it but I can't bring myself to see that as a permanent solution. Maybe it is, just seems like a patch rather than solving it at source.

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BigBirthdayGloom · 05/01/2014 19:01

Would you mind me asking a question on your thread, op? We have a condensation problem in our bedroom, nowhere else really. It's a late 1939's house so single skin wall and the wallpaper has peeled off the wall because of the moisture collecting on the wall of the bay window. I am now ventilating all day and night and the radiator will be working better now it's been bled! But there are a few cracks in the bay wall that match with cracks in the external window. Could it be a leak through that in addition to the two people daring to breathe in there all night? Also, window frame prob needs replacing as sill is a bit rotten. Is that relevant, possibly? Hope you get yours sorted, op, and thank you to folk like pigletjohn who help so much.

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TunipTheUnconquerable · 05/01/2014 19:04

There's lots of info from SPAB, particularly if it's an old building - they've done a few factsheets on damp that have a lot about it.
SPAB condensation Q&A

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specialsubject · 05/01/2014 19:22

I wouldn't worry about the person ranting about the safety of glass fibre (which anyone with two brain cells to rub together KNOWS has to be used with suitable precautions), given that they recommend a HUMIDIFIER for a damp property!

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Indith · 05/01/2014 19:29

Grin I just sort of skimmed over that part and translated it to dehumidifier.

Thank you. Shall read and investigate and probably come back with more questions. .

Hope you get somewhere with yours too person whose name I can't remember and can't scroll back to see as I'm on the app. Blush

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MaudLebowski · 05/01/2014 19:43

Gloom, without seeing it I think the breathing is your biggest issue :)
With the paper off if it were a leak I'd expect to see a line of darker coloured plaster, or the plaster coming away in a line over a leak, condensation looks more general wet, or not even particularly wet at all as it doesn't take much to loosen paper. It will be heading for the bay as, like the attic ceiling it will have no insulation and will probably be timber frame thus the coldest wall. It might be fixable when you replace the window sills if there turns out to be two skins of 'wall' and a gap between even a thin piece of insulation (rigid, not fluffy) in between will help enormously. The trick is fitting it without gaps or you get a condensation attracting cold spot over the gap. The insulation should go on the outside of the inner skin for best effect.
Have lurked extensively and never seen any sign of piglet selling anything or favouring any particular solution, I usually agree with him so feel no need to post myself!

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RandomMess · 05/01/2014 19:49

What heating is there up in the attic room?

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Indith · 05/01/2014 20:05

Not the central heating sadly. We have a decent electric radiator on a timer. Have changed the timing today in an effort to keep temp more stable. Though according to the max min thermometer the temp isn't all that far off the rest of the house.

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RandomMess · 05/01/2014 20:08

Hopefully the dehumidifier will really help Confused

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Indith · 05/01/2014 20:09

fingers crossed. Either that or the fiddling with plastic trick will show it to be a leak and we can fix it. Though dehumidifier could be cheaper than roofer and new velux!

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PigletJohn · 05/01/2014 20:19

I would be thinking about ripping all the plasterboard off and insulating all the walls and ceiling properly. I bet that's the trouble.

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Indith · 05/01/2014 20:27


what would you make of the insulation we have?

When we split it we increased insulation as was very cold and not having done the conversion we didn't know what was there. We added a layer of insulation plus plasterboard over the original. The room was made originally with eaves storage. We don't use those for storsge ourselves, it not being practical with the layout. The freebie insulation people added some insulation to those. There is some of that foil backed insulation on the wall bit then usual loft insulation on the bottom on the eaves storage area. I don't know how much you can put in there? Obviously still need air circulation under roof. Can see daylight at edges when you look into the eaves. The alcove itself I guess needs more insulation, it is the only bit that goes directly to exterior wall as we are mid terrace and then the back wall in the adjoining room has no alcove so is all eaves storage area so no direct outside wall. The only other bit of fall weer have is on one of the side walks adjoining an unoccupied house.
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PigletJohn · 05/01/2014 21:12

remember that the current standard for loft insulation is 270mm of mineral wool.

the fact that the loft is cold even though all the warm (and moist) air from the house will rise into it shows that it is poorly insulated.

rigid foam slabs have better insulation properties so can be thinner, but I haven't got the figures to hand.

A modern loft conversion would have foam slabs packed between the rafters, with another layer of plasterboard faced foam forming the ceiling. No cracks or gaps. There would be a breathable membrane under the tiles for ventilation of the cold side. All the knee walls would be similar, and so would party walls with an uninsulated loft on the other side. Without pulling the plasterboard off, you can't really fix it, although you could nail plasterboard-faced slabs to the ceiling, which would lower it, and the party wall.

50mm of foam or 100mm of wool would be a good start, though far short of current standards.

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MaudLebowski · 05/01/2014 21:25

Agree with Piglet, the lining board is called Thermaline super, and that would improve the insulation of the walls and ceiling. The moist air will still be looking for somewhere to cause trouble though so watch out for that if you do do it. I'd try keeping the door closed and tape over the bit that might be a leak first. I am lining my loft space at the moment and its costing about £800 to line a fairly big but simple attic.

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