31-12-2011, 08:11 PM
Hi Rob,
Time to read up on Relative Humidity and Dew Points. Here's the link I always trot out: http://pdoyle.net/content/view/44
Basically, air at a certain temperature with a certain relative humidity will have a "dew point". This is the point that water vapour carried in the air condenses. It's why a freshly poured glass of cold beer will always be wet on the outside.
There is no problem with high humidity as such, providing there are no cold surfaces to attract condensation. Similarly, there is no problem with cold, providing the relative humidity is nice and low. The whole thing is a balancing act.
Luckily, in a garage, most of the sources of humidity are nowhere to be seen - everyone is indoors, the cooker is indoors, the clothes are being dried on radiators indoors. So actually, a typical attached garage like yours actually has a pretty good head start - unless the tumble drier is out there
Some years back, I purchased a thermometer/hydrometer that (obviously!) reports the current temperature and relative humidity, but it also calculates the dew point based on those measurements. And with my trusty infra-red thermometer, I can have fun for hours. An example came about recently - we were without heating for a couple of months, and the house managed to get really very cold. It's an old Victorian terrace with solid walls, and we noticed that the front wall upstairs was damp. Fine downstairs, so clearly not "rising dampness", and no rain, so not penetrating dampness. Most people in this position would have panicked and called in the nearest damp treatment contractors, but luckily I'm a bit of an anorak about these things. I knew that the bedroom would be much more humid than downstairs, and I knew that the front wall would be colder than the rest - partly because the bay makes it more exposed. So I fetched the magic thermometer from the cellar and found that the dew point in the bedroom was 12C. With the infra-red thermometer, I was able to track the temperature of the walls in the bay and either side, and sure enough, anything that was wet was below 12C. Simple. Once the heating was fixed, the problem went away after a few days. Of course, drying out the walls takes energy, which is why gentle background heat throughout the day is more efficient than the traditional roasting in the morning and evening, but that's another story...
In short, suck it and see; I'm fairly sure you'll be fine
All the best,
Mark
Time to read up on Relative Humidity and Dew Points. Here's the link I always trot out: http://pdoyle.net/content/view/44
Basically, air at a certain temperature with a certain relative humidity will have a "dew point". This is the point that water vapour carried in the air condenses. It's why a freshly poured glass of cold beer will always be wet on the outside.
There is no problem with high humidity as such, providing there are no cold surfaces to attract condensation. Similarly, there is no problem with cold, providing the relative humidity is nice and low. The whole thing is a balancing act.
Luckily, in a garage, most of the sources of humidity are nowhere to be seen - everyone is indoors, the cooker is indoors, the clothes are being dried on radiators indoors. So actually, a typical attached garage like yours actually has a pretty good head start - unless the tumble drier is out there
Some years back, I purchased a thermometer/hydrometer that (obviously!) reports the current temperature and relative humidity, but it also calculates the dew point based on those measurements. And with my trusty infra-red thermometer, I can have fun for hours. An example came about recently - we were without heating for a couple of months, and the house managed to get really very cold. It's an old Victorian terrace with solid walls, and we noticed that the front wall upstairs was damp. Fine downstairs, so clearly not "rising dampness", and no rain, so not penetrating dampness. Most people in this position would have panicked and called in the nearest damp treatment contractors, but luckily I'm a bit of an anorak about these things. I knew that the bedroom would be much more humid than downstairs, and I knew that the front wall would be colder than the rest - partly because the bay makes it more exposed. So I fetched the magic thermometer from the cellar and found that the dew point in the bedroom was 12C. With the infra-red thermometer, I was able to track the temperature of the walls in the bay and either side, and sure enough, anything that was wet was below 12C. Simple. Once the heating was fixed, the problem went away after a few days. Of course, drying out the walls takes energy, which is why gentle background heat throughout the day is more efficient than the traditional roasting in the morning and evening, but that's another story...
In short, suck it and see; I'm fairly sure you'll be fine
All the best,
Mark
