Condensation in the Attic?

clvk07

Hi

It looks like that in the black material in the attic roof is wet and you can see drops of water. I thought that something happened to the tiles ( missing ) but I from the street I can't see any missing tiles. Also it seems that the wet is everey where on the roof. If it is condensation, any ideas how to fix it? There is a vent in the attic already. I checked and the insulation material which is on the floor of the attic was blocking the air from coming in beside the gutters. I moved it back in order for the water to come in, but I am not sure if that was the problem. Thanks

gsxr1

clvk07 wrote: »

Hi

It looks like that in the black material in the attic roof is wet and you can see drops of water. I thought that something happened to the tiles ( missing ) but I from the street I can't see any missing tiles. Also it seems that the wet is everey where on the roof. If it is condensation, any ideas how to fix it? There is a vent in the attic already. I checked and the insulation material which is on the floor of the attic was blocking the air from coming in beside the gutters. I moved it back in order for the water to come in, but I am not sure if that was the problem. Thanks

sounds like condensation for sure.

you have done the correct thing by moving the Inso from the soffit area.

the weather is very cold at the moment . -8 forecast for tonight.

leave it till weather conditions improve. Then access again.

the black stuff is called felt and provides a secondary barrier to your tiles.

GopErthike

seems to me you might have a problem with either your heating system pitching or your immersion overheating, either of these problems will send hot water to your storage tanks, thus alot of condensation.

elchanco

Sounds like the same problem I have been trying to solve since last xmas!
The condensation is caused by the cold weather/lack of ventilation & warm air from the house entering the attic.

The solution (from the advice I got) is to provide proper cross ventilation & seal any gaps where the air can escape the house to the attic... I’ve yet to solve my condensation problem... good luck!

RKQ

elchanco wrote: »

[The condensation is caused by the cold weather/lack of ventilation & warm air from the house entering the attic. [/font]

The solution (from the advice I got) is to provide proper cross ventilation & seal any gaps where the air can escape the house to the attic...

This problem is particularly noticable in current cold conditions - your home may be at 21 degrees while outside has reached -10. Your attic's temp is nearly as low as outside. There is no breeze or wind, therefore damp warm air accummolates in the attic and condensates.

Black Sarking felt does not breathe - so this problem will be more noticeable in a house with felt. Proper ventilation of bedrooms & bathroom below attic, may lessen the amount of condensation. Check all wall vents.

elchanco

RKQ wrote: »

damp warm air accummolates in the attic and condensates.

Black Sarking felt does not breathe - so this problem will be more noticeable in a house with felt.

Hi RKQ,

Is it possible to prevent warm air accumulating in the attic?

Is it possible to replace the felt with a more breathable material?

Cheers

RKQ

elchanco wrote: »

Is it possible to prevent warm air accumulating in the attic?

1. Yes its possible but very difficult. You could lay 500 guage plastic sheeting on plasterboard & timber joist - under insulation & tape all joints. Retro fit air tightness is difficult to achieve.
2. Draught seal attic access hatch door.
3. Seal around all water pipes entering attic, especially from bathroom.

elchanco wrote: »

Is it possible to replace the felt with a more breathable material?

1. Yes, you would remove the roof tiles, battens and felt. Lay a good quality breathable felt (Pm for details) and relay existing tiles as it should be possible to remove 90% intact.
2. Ensure your eaves are well ventilated first. There must be at least 50mm clear air gap between your felt and the top of the insulation.
3. It would be cheaper to install a "Ventilate Ridge" system, or ventilation tiles etc.
4. Cutting a wallvent in the gable might help ventilate your attic. Drill 100mm dia hole in wall.

elchanco

RKQ wrote: »

Draught seal attic access hatch door.

I have a loft ladder in my attic... Whats the best way to draught seal this!

cheers

clvk07

gsxr1 wrote: »

sounds like condensation for sure.

you have done the correct thing by moving the Inso from the soffit area.

the weather is very cold at the moment . -8 forecast for tonight.

leave it till weather conditions improve. Then access again.

the black stuff is called felt and provides a secondary barrier to your tiles.

thanks..... I have done the following

1. removed insulation from the soffit area and ensured all vents around the gutter are ok

2. sealed the attic door ( there were a gaps all around the door )

3. Left the dehumidifier on for few hours in the attic

4. Dried most of the wet from the felt

5. There is no hot tank in the attic.. There are two cold water thanks.. ( not sure why two???? )

Will check in few days if things have improved....

I think that the attic roof should have two vents. I can only see one from the attic. I think one is blocked... Will have to check where the other one is meant to be and cut the felt.....

GopErthike

Depending on how new your house is, you have two tanks because either,

a. one is for cold water storage, the other is the header/expansion tank to feed your heating system (if it is open vented)
(this is usually a smaller tank sitting on top of the bigger tank)

b. the two are cold water storage 'married' together to provide sufficient water storage, and you probably have a sealed heating system
(these are usually the same size)

If your immersion thermostat is faulty your water will get very hot and rise up the expansion pipe and pour into the cold water
storage tank, and give of steam/condensation.
The very same thing can happen with your heating system if it is open vented.

It's a common problem.

clvk07

GopErthike wrote: »

Depending on how new your house is, you have two tanks because either,

a. one is for cold water storage, the other is the header/expansion tank to feed your heating system (if it is open vented)
(this is usually a smaller tank sitting on top of the bigger tank)

b. the two are cold water storage 'married' together to provide sufficient water storage, and you probably have a sealed heating system
(these are usually the same size)

If your immersion thermostat is faulty your water will get very hot and rise up the expansion pipe and pour into the cold water
storage tank, and give of steam/condensation.
The very same thing can happen with your heating system if it is open vented.

It's a common problem.

Hi

I rarely used the immersion, I use the boiler for the hot water.What you mean with open vented? I have the boiler ( it has a thermostat in the hall ) in the kitchen and the vents beside which go out in the side entrance. The immersion is upstairs below the attic... tks

corribfitz

RKQ wrote: »

1. Yes its possible but very difficult. You could lay 500 guage plastic sheeting on plasterboard & timber joist - under insulation & tape all joints. Retro fit air tightness is difficult to achieve.
2. Draught seal attic access hatch door.
3. Seal around all water pipes entering attic, especially from bathroom.

1. Yes, you would remove the roof tiles, battens and felt. Lay a good quality breathable felt (Pm for details) and relay existing tiles as it should be possible to remove 90% intact.
2. Ensure your eaves are well ventilated first. There must be at least 50mm clear air gap between your felt and the top of the insulation.
3. It would be cheaper to install a "Ventilate Ridge" system, or ventilation tiles etc.
4. Cutting a wallvent in the gable might help ventilate your attic. Drill 100mm dia hole in wall.

Hi is it ok to use plastic sheeting over the joists and under the insulation
as im doing my attic insulation and was told on another thread that it would cause condensation and rot the joists. Any thoughts would be appreciated.( plastic sheeting - assume that polythene ?)
Cheers