Converted loft = Condensation

[skypie]

Hi,

I have had an ongoing problem with my roof and loft. I have had about 5 roofers out all with different theories to my problem.

I am getting reasonably bad damp on 3 of my walls upstairs. These are all outer walls and all by windows. At first we thought this was because of rain coming into the house (we were led to believe this!!). This didnt make sense however seeing as last year during the awful wet period in the summer we had no problems. It was only in the winter it started and when we had the heating back on. The latest theory therefore is condensation.

When we moved into the house a previous owner had done a loft conversion (professionally? doubt it!). After looking all over the net there are a few things which don't make sense.

I have added this photo album to show what I mean
http://good-times.webshots.com/album/562627123WsvIET

Above the walls which have the damp is damp looking insulation. This insulation appears to go right to the end of the roof which I believe is incorrect?

There is also no other signs of ventilation in the attic except a velux window. I can see no place where the air can escape.

The felt near the end of the roof is slightly moist but not soaking wet.

What do I do to get rid of the damp. Is it because of a lack of ventilation and/or the insulation covering any gap which needs to be there?

Thanks for any help.

 

[datarebal]

Very likely condensation, first pull the insulation back a little so it is not in contact with the felt. You can then try a little experiment yourself for free!!
Between the felt laps insert a piece of batten just big enough to hold the laps slightly apart allowing more airflow into the loft. This flow is just normal tile blowby and can be effective..
If the problem clears then consider getting some vent tiles fitted..

 

[skypie]

If i were to have vent tiles fitted is it really just a case for a roofer to come along and just take one or two tiles out and replace them with vent tiles or is it a much bigger job?

Im not too sure what you mean by a "batten" to keep the felt overlaps open. Is that just a small piece of wood? How would I get them fixed in position?

Thanks a lot!

 

[datarebal]

Yes it is an easy job on your roof..

by batten I mean short pieces of timber 19x38 or thereabouts
keep them in position by either notching them so the hang of simply put a screw in then so they dont slide all the way down...usually they fit snuggly