Please help!! Dampness due to high humidity

[Supernatural323]

Hi All,

I have an ongoing problem, that, I do not know what to do about. I live in a 100 year old stone house, 5 years ago I have rendered the outside and re-plastered the whole inside and double glazing windows. I also understand that this is bad as the walls need to breath. It's a 3 bedroom house with a further room in the attic. Humidity levels range between 60% to 80%, Windows are soaked in mornings. I have fan for bathroom and kitchen, and we do not dry clothes in the house, except for in tumble dryer.

I have looked at systems like Mr Venty, but these units, as I understand need fresh air from an attic, which I do not have, due to it being a room.

Can anyone give me any advise? it is very appreciated

Regards

John

 

[^woody^]

Trickle vents in the window frames.
Passive vents in the walls - eg Vent-Axia Freshvent
Or you can get a positive pressure fan (that Mr Venty thing) that is suitable for properties without a loft - search for Nuaire Flatmaster for example.

 

[KenGMac]

Supernatural323, Hi.
I possible? how about you consider that your vent above your Cooker, if you have one is vented to the outside? most extractors above the Cooker simply recirculate the steam laden air into the house.
Likewise, an extract fan in the bathroom that moves the wet air from the bathroom outside is also advisable, or simply leave a window open in the Bathroom when finished with a shower or bath?
Ken.

 

[Supernatural323]

Hi ken,
Yes, the extractor fans of both kitchen and bathroom are vented outside.

 

[AronSearle]

I live in a 100 year old stone house

This is your problem.

Stone is cold, such houses used to have roaring fires and very high amounts of airflow which helped to prevent such condensation.

In the short term increase ventilation, and increase heat output (those energy companies need your help making money!).

Long term seriously consider insulating the place properly, it will pay-back over time.

 

[Supernatural323]

My house is very well insulated on the roof, I'm not going to go down the avenue of insulating the walls. The best option would be the positive pressure system.

Don't know anything about them. Can anyone recommend? As I said previously, it can't go in the loft and would have to go through a wall. Alot of work as it's a stone house.

 

[noseall]

I'm not going to go down the avenue of insulating the walls.

You are going to have a battle on your hands then.
How come when you had a golden opportunity, either when re-rendering the outside or re-plastering the inside, you didn't consider insulating any of the outside walls?

 

[Supernatural323]

Because I was young and beautiful then. I started the whole project 8+ years ago with no previous experience whatsoever, I had never heard of insulating walls.

Any further info on these Positive pressure systems woould be great full.

 

[Joe Malone]

Positive pressure systems are a complete waste of money so do not install one. The BRE recently completed a piece of research on their effectiveness both at the BRE's test property and on a housing estate in Wales. The upshot of all this is that residents imagined that they made a difference despite all evidence to the contrary. Here are two of the key published findings:

1. ¨Input ventilation was found to be effective in reducing relative humidity levels by around 10%RH in the test house, even when internal doors were closed. Vapour pressures reduced overall by 0.2kPa. The unit was shown to be more effective upstairs than downstairs.

2. In the field monitored houses input ventilation was not consistently effective in reducing relative humidity. When absolute humidity excess over that outside was examined it was effective in the most humid houses but did little in the dryer houses. Even in the cases where it was effective there were often inconsistencies between rooms in the same house.

They are far from being the magic cure for condensation that these companies claim and you should think very carefully about whether a 10% reduction in overall RH will be of benefit because in my opinion it won't. I've never installed one but I've been to many properties where they have had little or no effect on the condensation damp problem.

 

[^woody^]

Positive pressure systems are a complete waste of money so do not install one

I don't agree.

We fitted these to many system built properties that were condensation prone, where we had taken other measures, which were unsuccessful, and we knew that the tenants would not heed advice or change their habits. And they did work.

 

[noseall]

Positive pressure systems are a complete waste of money so do not install one

I don't agree.

We fitted these to many system built properties that were condensation prone, where we had taken other measures, which were unsuccessful, and we knew that the tenants would not heed advice or change their habits. And they did work.

Don't get roped in Woods. Joe Narcissus Malone is paid via a fan manufacturerer and is brainwashed.

 

[noseall]

Oops

 

[AronSearle]

My house is very well insulated on the roof

And?

I'm not going to go down the avenue of insulating the walls. The best option would be the positive pressure system.

I can't see how it matters whether it is a positive pressure system, or if existing fans are increased in capacity or frequency of use.

Air changes are air changes.

Personally I would go with a desiccant dehumidifier rather than more air changes, will dry the air a bit as well as provide heat (warmer walls = less condensation).

Still throwing money out the window either way.