Mould - OK, ventilate, but how

[goodolpete]

I've got a 6ft wide by4 ft deep alcove in my bedroom. For the last two quarters I've removed ceiling mould with Dettox mildew and mould remover and repainted. Now it's back again:

've scanned previous postings and the advice has been ventilate. I can't leave a window open as anyone could climb on my garage and get to the window. The window is double glazed so I'm loath to put anything through it. I've drilled large holes in the top of the frame and put a cover over it. Is there a way to put anything through the ceiling into the loft and out under the eaves? TIA, |P

[chris French]

In message , goodolpete writes

You are sure this is from inside, not a small leak from outside?

You could potentially put ducting through and out at the eaves, with maybe a small extractor fan, if there is enough space (if this is a bay with a roof over maybe not)

But more to the point, think about the source of the problem. The main sources of moisture (other than people) in the home are the bathroom and the kitchen. Do you have adequate ventilation in those areas?

[meow2222]

vent options: window fan (hole in glass, butt ugly) wall mounted fan (big hole in wall) vent through ceiling into loft ducting to outside a window lock that will lock it in the 1/4" - 1/2" open position.

a dehumidifier has some advantages though. Hassle free to install, similar run costs, no heat loss, and can be used for this:

[fred]

In article , goodolpete writes

doesn't require flash, eg.

[Phil L]

which has soaked the ceiling material, whether it be plasterboard or lath and plaster, and the mildew you are seeing is a result of that - a wet ceiling can take weeks or even months to dry out once the leak is sealed, but your priority must be to seal this portion of the roof - luckilly it looks fairly close to the guttering (which could also be the cause of the leak), either way it could be sealed up with any roof sealant, but OTOH, the leak could be further up the roof and the drip is rolling down the inside of the roofing material and saoking into the insulation where it's cramped in the eaves - first port of call is the loft, preferably when it's raining and take a hefty torch - if you pinpoint the leak, you can take measurements and make it easier to locate once you are on the roof.

[robgraham]

Ventilation is one of the keys, but insulation is the other in that if the water vapour in the air, from presumably the kitchen/bathroom, meets something that is cold enough for it to condense on, then you will in due course get mould. Even if you ventilate well in the affected area, you've still got cold surfaces, so either eliminate the source of the water vapour before it gets to the bedroom or make the walls warmer.

All my mould areas disappeared, and we had many, when I stripped off the old lathe and plaster lining, put in insulation, dpm, and relined with ordinary p/b.

Rob

[Dave Liquorice]

browsers are capable of displaying .gif and .jpg natively they do not need anything else.

[The Medway Handyman]

Did you use a specific stain block paint over the old mould stains? If not it could just be the stain bleeding through the emulsion.

[PeterC]

not required (seen in Opera, so no problem).

[geraldthehamster]

I would check first that you don't have a leak in the roof above - can you get to that corner of the eaves and see if the rafters are wet?

Assuming it's condensation, first consider where the moist air is coming from. Does your bathroom have an extractor fan? Do you keep the door shut when using the bathroom?

If all that is accounted for, and you need to provide ventilation in the bedroom (sleeping people, breathing, put a lot of moisture into the air), I'd get a builder to fit a large air brick in the wall, and cover the inside with a hit-and-miss vent (the type of grille that can be opened and closed).

Finally, decent loft insulation will make the ceiling less cold, and water vapour less likely to condense on it.

Regards Richard

[Man at B&Q]

What's above that bit of ceiling? Probably very little, causing a cold spot where condensation occurs. It may be as simple as insulating above.

MBQ