Loft Condensation problem

[fivefooteightandahalf]

Hi all
We have moved into a detached house and have a problem with condensation seeping through on all the outside walls, bedroom bathroom and landing. we have been told this may be due to ventilation in the loft, the roof is insulated and is covered on the inside with felt. can anyone confirm this maybe a vent problem? there is 1 vented roof tile that I can see. Thanks.

 

[kevindgas]

no expect on roofing but only 1 vent? how would the air flow? i would think you need a positive and a negative effect to get cross circulation through the loft so a vent on each side of the roof creating a venturi effect?

 

[masona]

there is 1 vented roof tile that I can see. Thanks.

Sometime the roof vent are only ventilating under the roof tiles between the roofing felt so may not be ventilating your roof, do you have any soffit vents?

 

[JohnD]

you say the condensation is in the loft?

//www.diynot.com/forums/viewtopic.php?t=160032

or do you mean in the rest of the house?

//www.diynot.com/wiki/building:condensation_in_houses

Do you do any of the following:

1) Drape wet washing about the house

2) take baths or showers without running an extractor fan?

3) boil cooking pans without using an extractor hood (nor a recirculator)?

4) keep the windows closed all the time?