Condensation in the loft

[ar2r]

Hi . I've been fighting with the condensation for some time now . It is just dripping from the felt underneath the roof tiles .

Drilled some holes and installed vents ( one every 60-70cm on both sides of the house - those bright points on the photos

put some plastic between felt vents .

even though it is not that cold outside still dripping like in the winter when it freezes up ((

got some storage in the so maybe it is blocking the airways but have not a clue (

Any help would be highly appreciated

Thank you

Artur

 

[JohnD]

does anybody drape wet washing inside the house?

Are there holes in the ceiling, for example downlighters or pipes?

how is the bathroom ventilated?

 

[JP_]

I had this problem.

I added a lot more vents. Maybe 40 in a 7m loft space. Basically, every felt overlap was opened a bit, some with those plastic vents, many with bits of pipe insulation.

There was a small leak in the kitchen extractor, but that could not have been the whole problem as we didn't use the hob a massive amount. Just kitchen and living room below loft. Well, WC too but that had extractor.

Extra vents did the trick. Think my builder didn't use breathable felt ... or put in any vents! Took a good few days to dry out though, was obviously a lot of moisture there for a month or so. Was probably this time last year when it got bad ...

Yep, ordered 25 Roofing Felt Lap Vents on 28 December 2018, and probably shoved in another 25 bits of tube and insulation. Problem solved.

 

[ar2r]

Hi

does anybody drape wet washing inside the house?

got a condenser dryer downstairs so that should be ok


Are there holes in the ceiling, for example downlighters or pipes?

There are downlighters in the bathroom covered with insulation ( with attachments )

how is the bathroom ventilated?

with an open window

 

[JohnD]

Hi




with an open window

what?

 

[ar2r]

what?

sorry got the quoting messed up

got a condenser dryer downstairs so that should be ok

There are downlighters in the bathroom covered with insulation ( with attachments )



####how is the bathroom ventilated?

with an open window

 

[ar2r]

it looks like most of it is on one side ( well one side is nearly 80-90% covered with water , the other side ( where the bathroom is ) looks a lot better

 

[JohnD]

save up for a bathroom extractor fan. The warm steamy air will be rising through the holes. moisture can even get through a plaster ceiling, but not so freely.

 

[ar2r]

save up for a bathroom extractor fan. The warm steamy air will be rising through the holes. moisture can even get through a plaster ceiling, but not so freely.

I will be renovating the bathroom hopefully next year as wont be able to stick a fan in at this moment in time .

Do you think that the roof felt vents would help - I've got about 10 of them installed but maybe like

 

[JohnD]

they will, but I think the problem is that you have excessive amounts of water vapour rising into the loft. An extractor creates suction in the bathroom and prevents the damp air moving into other parts of your home.

IMO the gaps I can already see would be sufficient if the damp load was not excessive.

The roofing felt will be very cold, sometimes freezing in a cold night, so is prone to condensation and even icing.

If you are handy you can make covers for the downlighters. Assuming you have LEDs in them so they are not very hot, one way I like is to make an open-ended box out of plasterboard (this is very easy if you know how to score and snap it) and rest it on the ceiling so the lamp is inside. Plaster is also fire resistant so will also delay the risk of a fire getting to the roof. In rooms that are not steamy it will reduce draughts and heatloss. I wouldn't cover with paper, card or wood which is flammable. You can also buy special intumescent hoods which are designed for fire protection.

Some lamps, especially halogens, get very hot and may have instructions for ventilating to keep them cool.

 

[JP_]

moisture can even get through a plaster ceiling, but not so freely.

Thinking about my loft again ... I was planning to overboard my bathroom ceiling at somepoint, would it be better to use something like GTEC Vapour Board Duplex Plasterboard?
My bathroom has a loft hatch which I need to close up. Probably needs a better fan too ...

 

[JohnD]

I approve of the plasterboard with the foil coating on the back, because it seems to me that, with loft insulation on top to keep it warm, water vapour will neither condense on it nor pass through it, and it is quite cheap and easily available.

But I have no scientific study.

Overboarding also reduces noise transmission, which is great.

However, if you have a bad water leak above, it is very difficult to dry out.

 

[JP_]

is there a ceiling paint that blocks vapour?

 

[JP_]

And ... do we really need the roof covered in felt? The loft above the old side of the house is dry, no roof felt. Rain never gets in and we've had some pretty heavy rain this year.
Would it be better to remove some felt from the roof to increase airflow? Why do we need that felt?

 

[ipbr21054]

Afternoon,
I would also like to follow this post as i have the same kind of thing & not sure how to tackle it.
In our Bungalow we have 4 roof vents,2 on one side towards the bottom part of the roof & 2 on the other side towards the top of the roof.
Looking in the loft yesterday i noticed that the side with the vents towards the top is pretty much dry,not sure why but other hald put some socks in these vents some time ago as she said it was could up there ?
The other side however has condensation on the black felt,the 2 vents on this side are open.in that i mean no stocks.

Reading the other replies above our Bathroom has an extractor fan but we also open the window a little when using the shower / bath etc.
The Kitchen has an extracor fan above the hob which sits ontop the units & the directly out the wall,none of the ducting for the hob leaves the kitchen.

There are no downlighters in any ceiling.
The loft area has that insulation where its yellow in between each floor joist etc.
One of two of the roof joist has some white sediment on but maybe that is salt etc from where the condesation had dried out etc ?

Any advice would be great.

Many thansk