TIMBER FRAME BUNGALOW . Damp can be a major issue in the home. Find answers to questions or post your own here.

[oliver4649]

i have a timber frame bungalow that is clad on to with spar render, my loft area is roof t and g clading on frame new slat roof on breather menbrane with all roof slate vents ,the gable end walls are not insulated you can see the stud work and the outer skin plastic menbrane, over this menbrane there is condansation there are two externel vents two each of gable end wall, does anybody know how i can stop this the building is about 1980 it does not apear to be breather menbrane outer walls.

[SPUD1701]

Hi

This sounds like condensation in the loft, if it has been recently re roofed, I believe you do not have enough vents at a high and low level, previously the olf roof would not have been sealed as tight and would have naturally vented this space.

Make sure any insulation on the ceiling is pulled back from the edges where it comes into contact with the pitch of the roof, this will allow air movement, if there is insulation make sure it is cross layered over the timbers to prevent heat loss from the room below.

Lastle make sure that the vents that have been installed are correct for the size and pitch of the roof - generally you should be looking for vents providing 5,000mm squared per metre at high level and between 10,000 - 25,000mm squared per metre at low level - British Standards for roo f ventilation.

[oliver4649]

Hi

This sounds like condensation in the loft, if it has been recently re roofed, I believe you do not have enough vents at a high and low level, previously the olf roof would not have been sealed as tight and would have naturally vented this space.

Make sure any insulation on the ceiling is pulled back from the edges where it comes into contact with the pitch of the roof, this will allow air movement, if there is insulation make sure it is cross layered over the timbers to prevent heat loss from the room below.

Lastle make sure that the vents that have been installed are correct for the size and pitch of the roof - generally you should be looking for vents providing 5,000mm squared per metre at high level and between 10,000 - 25,000mm squared per metre at low level - British Standards for roo f ventilation.

yes iv got all ventalators two each gable end in roof two each side,not sure about cross layered insulation i will see that later, i now that my loft is about 3% warmer when heating on,its the gable end walls that are bare between studs,the menbrane has condensation on i can feel the menbrane on the external render i think that this area has been done in render on mesh, will it inprove if i use an insulation as this seems to be the cold spot.

[SPUD1701]

Hi

This sounds like condensation in the loft, if it has been recently re roofed, I believe you do not have enough vents at a high and low level, previously the olf roof would not have been sealed as tight and would have naturally vented this space.

Make sure any insulation on the ceiling is pulled back from the edges where it comes into contact with the pitch of the roof, this will allow air movement, if there is insulation make sure it is cross layered over the timbers to prevent heat loss from the room below.

Lastle make sure that the vents that have been installed are correct for the size and pitch of the roof - generally you should be looking for vents providing 5,000mm squared per metre at high level and between 10,000 - 25,000mm squared per metre at low level - British Standards for roo f ventilation.

yes iv got all ventalators two each gable end in roof two each side,not sure about cross layered insulation i will see that later, i now that my loft is about 3% warmer when heating on,its the gable end walls that are bare between studs,the menbrane has condensation on i can feel the menbrane on the external render i think that this area has been done in render on mesh, will it inprove if i use an insulation as this seems to be the cold spot.

Hi
if your loft is warmer when the heating on - then heat must be escaping from the room below into the cold space above, the gable walls are not part of any room in the loft and therefore do not have to be insulated, the insulation for the bungalow should be on the horizontal ceiling, this is your thermal break.
Try cross layering the insulation across the ceiling timbers, this should limit any heat being lost between insulation and timbers, regarding the roof ventilation by sounds of things you may not have enough at high and low level, check with internet on type of vents this will tell how free air each vent provides, but you are looking for either continuous high level or vents that give 5,000mm2 free air every metre and 10,000mm2 per metre at low level. What you ahd in the way of ventilation before was probably okay due to air leakage through the old roof, this has now been sealed by new roof membrane, letting no fresh air or out.