Garage temp to stop damp

[Bushbaby]

Hi All,
I've finally got my garage sorted (pics to be posted very soon) to work out in my garage (its integral to the house). I've been adding some of my working test gear into the garage and it has made me think about dampness. My garage does appear to be relatively dry, it doesn't leak at all and its always heated to ensure that its above 10 degree C at all times. Do I need to make any other conciderations with respect to damp avoidance??

Thanks

Rob

[pwdrive]

Hello Rob, I would say that if the house/garage is of cavity construction (generally post WW2) and that it is all structually ok ie: no water/visible damp ingress then it's all down to ventilation/heating to regulate the air moisture content in there.
As Al as already mentioned no parrafin or self contained gas heaters and you should be ok.

Lawrence.

[Bushbaby]

Hi Lawerence,
After I had posted I thought its more about water ingress than temp really. The house was built in the 60s with good old cavity walls. These have been filled with glass beads (its a Knauf glass mix) and I do know that the outer garage walls are the same cavity wall construstion as the rest of the house and was insulated also.
The only issue is the slab floor but this raises cold, rather than damp issues and ensuring that water doesn't get under the up an over garage door.

Regards

Rob

[pwdrive]

Hello Rob, if like you said in your first post that it doesn't feel damp in there then it probably isn't, especially as it is of modern construction, if damp does enter into the equation, then quite often it can be due to human occupation, I would have thought for normal workshop use everything should be ok if a vapourless form of heating is used and the garage space is not used for hanging up washing etc.

Lawrence.

[Mark Hennessy]

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

[Mark Hennessy]

Oh, and my temporary workshop is in a cellar, where the relative humidity is generally above 70% and temperatures are below 15C. It's well ventilated, and I might use an electric heater when I'm down there, but conditions are almost certainly worse than a relatively modern garage, yet I have no problems. I'm a bit sensible about keeping things away from the floor and walls, but that's all. No instances of surface rust or rotten wood yet...

[Bushbaby]

I thought that you would like to see some pics of my newly cleared out (ho ho) den!

Regards

Rob
   
   
   

[pwdrive]

I think you have it there Rob, looks like a good space.

Lawrence.

[Mark Hennessy]

I counted 4 Roberts sets (an R303 or RIC1, a RIC2 or R505, not sure what the red one is, nor the black one by the oil can). But no Hackers. I'm disappointed. Some nice looking test gear

Mark

[Bushbaby]

Hi Mark,
No Hackers (yet!) - loads more Roberts though including RIC1's (two blacks are) and 2's (the red one is), several R300. I've some more Roberts indoors including an R900 which is great set and is used daily and works really well.

Regards

Rob