Condensation in loft.

MisterNick

Jacko220 - thanks for the comprehensive reply. i think I am going to need some time to reread it before I understand but will come back with any questions.

MisterNick

Thanks Housebuyer 143 - At the moment I am the same, as I thought there was sufficient ventilation up there. i will need to keep reading

MisterNick

stuart45 said:

grumbler said:

MisterNick said:

I have been particularly careful in making sure that i left gaps at the eaves and between the insulation and the loft boards.

Was I always going to get this, and haven't realised. Is there anything I can do to prevent it

Another important step is to prevent moist air getting into a loft from the house. Without supply of moisture there will be some condensation, but no more than on your car outside.

The trap hatch is usually the worst offender.

stuart45 said:

grumbler said:

MisterNick said:

I have been particularly careful in making sure that i left gaps at the eaves and between the insulation and the loft boards.

Was I always going to get this, and haven't realised. Is there anything I can do to prevent it

Another important step is to prevent moist air getting into a loft from the house. Without supply of moisture there will be some condensation, but no more than on your car outside.

The trap hatch is usually the worst offender.

Thanks Grumbler and Stuart.
I wouldn't say there is a huge amount of condensation, but there are drips on the boards and stuff in the loft.

I need to do something withe loft hatch as i haven't done anything yet. somebody mentioned 25mm of elutes, which I think should be doable. the hatch drops and the ladder drops.

MisterNick

Grumbler, I only have recessed lighting in the bathroom and I (rightly or wrongly) used lids for those.

housebuyer143

MisterNick said:

stuart45 said:

grumbler said:

MisterNick said:

I have been particularly careful in making sure that i left gaps at the eaves and between the insulation and the loft boards.

Was I always going to get this, and haven't realised. Is there anything I can do to prevent it

Another important step is to prevent moist air getting into a loft from the house. Without supply of moisture there will be some condensation, but no more than on your car outside.

The trap hatch is usually the worst offender.

stuart45 said:

grumbler said:

MisterNick said:

I have been particularly careful in making sure that i left gaps at the eaves and between the insulation and the loft boards.

Was I always going to get this, and haven't realised. Is there anything I can do to prevent it

Another important step is to prevent moist air getting into a loft from the house. Without supply of moisture there will be some condensation, but no more than on your car outside.

The trap hatch is usually the worst offender.

Thanks Grumbler and Stuart.
I wouldn't say there is a huge amount of condensation, but there are drips on the boards and stuff in the loft.

I need to do something withe loft hatch as i haven't done anything yet. somebody mentioned 25mm of elutes, which I think should be doable. the hatch drops and the ladder drops.

I am buying some polystyrene insulation board 50mm thick to cut and glue to the loft hatch. Hopefully that will help insulate it.

MisterNick

ashe said:

I've got a similar problem, and was about to update my other thread. I've seen on my local town FB noticeboard a lot of people saying similar things about their loft and condensation, and it was suggested to  insert lap vents. These are pieces of plastic that go between those layers of felt and allow ventilation. I suspect you have a similar problem as me in that once moisture is in there it doesn't have anywhere to go because of the bitumen felt, so it condenses on that then is dripping onto the insulation. 

Ashe, thanks for this. I have just googled these and they seem easy to fit. 
Have you fitted them and did they work.

i wasn't sure whether that was your loft, but I haven't fitted my boards up to the eaves like that, mine come about 20mm inside the rafter.

stuart45

MisterNick said:

stuart45 said:

You probably need more ventilation. You can't have that amount of moisture dropping down all the time. You might need eaves to ridge ventilation.

Thanks
Just googled eaves to ridge ventilation, but it all seems to be fitted when installed. Am I missing something?

Normally is, but can be retro. Try increasing your eaves to eaves first. Is your roof a steep pitch?

ashe

MisterNick said:

ashe said:

I've got a similar problem, and was about to update my other thread. I've seen on my local town FB noticeboard a lot of people saying similar things about their loft and condensation, and it was suggested to  insert lap vents. These are pieces of plastic that go between those layers of felt and allow ventilation. I suspect you have a similar problem as me in that once moisture is in there it doesn't have anywhere to go because of the bitumen felt, so it condenses on that then is dripping onto the insulation. 

Ashe, thanks for this. I have just googled these and they seem easy to fit. 
Have you fitted them and did they work.

i wasn't sure whether that was your loft, but I haven't fitted my boards up to the eaves like that, mine come about 20mm inside the rafter.

No thats just a product photo from amazon - I've ordered 10 of these to start me off and will see how I get on. In the interim I have cut some 1-inch rings of foam pipe lagging and inserted that behind the felt overlaps to hold them open in an attempt to allow some air to circulate. They seem easy to fit and there are a lot of positive comments around them on my local towns FB noticenoard where there have been a lot of comments about condensation in loft. I suppose it makes sense if there are ways for air and heat to get through even if its just a bit, its going to condense in there with no ventilation. I'm hoping 10 will be enough but reckon I will need more

https://youtu.be/vDWzITdEt5o

MisterNick

stuart45 said:

MisterNick said:

stuart45 said:

You probably need more ventilation. You can't have that amount of moisture dropping down all the time. You might need eaves to ridge ventilation.

Thanks
Just googled eaves to ridge ventilation, but it all seems to be fitted when installed. Am I missing something?

Normally is, but can be retro. Try increasing your eaves to eaves first. Is your roof a steep pitch?

I have just looked again at this, and I think it is probably beyond my ability. We are having some extensions built next year, and so will have a roofer on site who i will ask. Do you think I am understanding this correctly.

I have looked at the lap vents that Ashe posted, and it looks as though those will introduce more ventilation and are easy to fit.

Once again thanks for replying

ashe

Another thing I have seen mentioned, which I have not checked in ours yet, is if you have a cavity wall make sure it has been capped in the loft otherwise any moisture in the cavity basically evaporates upwards.