Icicles on roof edge, condensation or leaking roof?

[JohnnytheWalker]

Hi, I've noticed icicles on my roof edge, just on one side of the house. Had a look up the loft and found droplets of water all over the roofing felt, I'm guessing it's something to do with it. Wonder if it's condensation or a leaking roof.
Any ideas folks?
Here are some pics:

Icicles

• JohnnytheWalker
• 20 Jan 2013
• 1

Felt 1

• JohnnytheWalker
• 20 Jan 2013
• 1

Felt 2

• JohnnytheWalker
• 20 Jan 2013
• 1

Felt 3

• JohnnytheWalker
• 20 Jan 2013
• 1

 

[Alastairreid]

Condensation!

 

[Burnerman]

I get this every year with my place.....loads of snow on the roof, and local melting around the gutter area. This forces melt water back up into the soffits which freezes and thaws as the day goes on, causing similar issues.
Its been bad enough one time to leak actually in the house over the head of the window frame, but thats rare.
I know my underfelt isn't good at gutter level, but it will have to stay that way.
So, if your issue isn't condensation, (and I think Alistair is right) it could be the same as mine.
John

 

[JohnnytheWalker]

Maybe a combination of both?
Wonder if putting vents in the roof will help? or more insulation?
Any advice welcome, thanks.

 

[Burnerman]

Certainly if there's condensation up there then soffit ventilators will help......you need around 300mm of insulation above the ceilings anyway, but the stuff shouldn't touch the felt anywhere, or fill up the soffit boxes.
The more draught up there the better really, but naturally its vital to protect any water tanks that may be up there.
There's no need for ridge tile vents here.
John

 

[JohnnytheWalker]

Does that mean that soffit vents alone will supply enough ventilation - wonder how many I'll need in this setup? Cheers.

 

[^woody^]

When it's minus whatever outside, and 20°C inside, then condensation is almost inevitable in a roof space, whether vents are fitted or not.

If anything, investing in more insulation will not only keep heat in, but lower the loft temperature to narrow the temperature differential between inside and outside

Only consider extra ventilation if condensation is occurring for long periods of time when the weather is more temperate - ie autumn and spring

As an easy fix, just separate the felt laps in the loft if you want to. Wedge a couple open at high and low level, with some bits of wood or cardboard.

 

[JohnnytheWalker]

Re. the quick fix "separate the felt laps". Is this to allow more ventilation through the roof?
Guess more insulation would help too then?
Cheers.

 

[^woody^]

Re. the quick fix "separate the felt laps". Is this to allow more ventilation through the roof?

Yes.

Roofs are quite leaky (in terms of air!), and it just helps move air in and out a bit more.