Trickle vents

[Michaelsf90]

Our utility room is polycarb roof, single skin brick, foam backed plasterboard. Like polystyrene stuff. Anyway at the bottom of the wall especially on the north facing side we are getting bubbling paint. Its condensation. If I open the back door it drys out no problem

So we are having our back door replaced. I was wondering is a trickle vent worth it and would it make much difference or would I be better off getting a dehumidifier for the winter months. I'm more bothered about noise intrusion and heat loss. Plus we want a composite and we cant get a trickle vent in composite. I know most window companies arent keen on trickle vents. It's only a problem like from November to february

 

[Wayners]

Get dehumidifier and humidity monitor imo.. Those vents do nothing imo other than let cold air in.. You run dehumidifier until humidity shows as being low then turn off at night. Windows will be clear in the morning and you start all over again

 

[johnny2007]

Open the windows an hour a day.
This should be done everywhere, not only in problem areas.

 

[Mottie]

Mrs Mottie has taken to doing that lately. Not for condensation, but to "blow the Covid away".

 

[Michaelsf90]

There are no windows. It's a polycarb roof and the door. The roof let's all the light in. And its condensation on the walls at the bottom above the skirts causing paint to bubble. When I've left the back door open slightly the damp and cold walls have dried out so its definitely condensation. I'm wondering what a decent solution would be during the winter months. It's either dehumidifier or would an extract fan that comes on when lights are on be the answer?

 

[Wayners]

Open the windows an hour a day.
This should be done everywhere, not only in problem areas.

Let all the winter damp air in and lower the temperature to 5c or colder.. Why do people think that the answer? What needed is insulation to lower the surface dew point and dehumidifier to dry the property so there is less moisture in the air and furniture, carpets ect.. Just saying. It's amazing when you see all this in action...

 

[johnny2007]

There are no windows. It's a polycarb roof and the door. The roof let's all the light in. And its condensation on the walls at the bottom above the skirts causing paint to bubble. When I've left the back door open slightly the damp and cold walls have dried out so its definitely condensation. I'm wondering what a decent solution would be during the winter months. It's either dehumidifier or would an extract fan that comes on when lights are on be the answer?

No windows: that's your problem.
Keep the door open an hour a day all year round.
As said, this should be done in every property.
In new flats, the lease states that the tenant must ventilate the property daily, this is probably because they're prone to condensation.

 

[JohnD]

Let all the winter damp air in

You misrepresent the moisture content of cold outdoor air, and ignore the reality of Relative Humidity.

 

[johnny2007]

Let all the winter damp air in and lower the temperature to 5c or colder.. Why do people think that the answer? What needed is insulation to lower the surface dew point and dehumidifier to dry the property so there is less moisture in the air and furniture, carpets ect.. Just saying. It's amazing when you see all this in action...

Wrong, it's a misconception.
Even wood will dry outside if not subjected to rain; try leaving wet wood under a canopy.
I see so many damp places and all suffer of the same problem: the owners do not open the windows so there's no ventilation.
In fact, under the same misconception I have seen windows taped shut and houses rotting away with condensation dripping from the ceiling and walls.

 

[JohnD]

Anyway at the bottom of the wall especially on the north facing side we are getting bubbling paint. Its condensation.

No, it probably isn't.

Water vapour is lighter than air so it tends to rise to the highest parts of the room.

Condensation lies on the surface of the wall, it does not emerge behind the paint and push it off.

To check, tape a piece of clear plastic tightly to the wall. If water appears behind the plastic, on the wall side, the water is coming from the wall. If it forms on the room side it's condensation.

After you have confirmed that you have a wet wall, consider where the water is coming from. Typically if the floor is concrete, it will be coming from below, often a plumbing or drain leak. It might be from water on the outside of the wall, such as a drain leak, spilling gutter or bridged DPC.

Photos of the wet wall, inside and out, will be informative.

BTW, cold outdoor air holds less water than warm indoor air, so it does not cause condensation inside a house.

Ventilation removes water vapour from a house.

 

[JohnD]

When I've left the back door open slightly the damp and cold walls have dried out

Yes, ventilation dries out water.

That's why a washing line, outdoors on a windy day, is so effective.

 

[Wayners]

Our bathroom is in the centre of our house. No window and because of bedroom above (bungalow loft conversion) has 240mm ceiling void stuffed full of insulation with chicken wire holding because of fire regs. We have a extractor vented 5m through soil pipe in void but not always on because of noise if there is a child upstairs at night. It's like a stream sauna at times but give it 20 mins it's all dry. No mould. Not flaking paint on ceiling which is just standard retail dulux matt. Painted in 2007 and still good. I figure the walls and ceiling are 20c+ so room dries out rapid like a mopped floor. Had we a window and it was open I doubt things would be the same hence I think windows do nothing.. Warm the surfaces up or get a dehumidifier

 

[johnny2007]

Our bathroom is in the centre of our house. No window and because of bedroom above (bungalow loft conversion) has 240mm ceiling void stuffed full of insulation with chicken wire holding because of fire regs. We have a extractor vented 5m through soil pipe in void but not always on because of noise if there is a child upstairs at night. It's like a stream sauna at times but give it 20 mins it's all dry. No mould. Not flaking paint on ceiling which is just standard retail dulux matt. Painted in 2007 and still good. I figure the walls and ceiling are 20c+ so room dries out rapid like a mopped floor. Had we a window and it was open I doubt things would be the same hence I think windows do nothing.. Warm the surfaces up or get a dehumidifier

Whatever you decide to do, do not keep the room unventilated.

 

[Michaelsf90]

I have mini trunking running around the bottom and it's damp on top of that. Behind I couldn't tell you. Is the paint bubbling because condensation is forming on top. Over time forming cracks then its getting underneath it. I scraped the bubbling paint off. It also was bone dry behind the paint once it had come off. It felt very cold to the touch but wasnt damp in any way

 

[JohnD]

Stand back and take some wider pics please