Keeping garages dry in winter

[MikeNash]

Re insulation, rather than 6mm ply I suggest you look at this polystyrene sheet

http://www.wickes.co.uk/polystyrene-25m ... vt/210801/

Its probably cheaper than ply and will insulate far better. Do you have the thin metal "up & over" doors on your garage? They'll be especially worth lining.
And draft excluder like this http://www.wickes.co.uk/heavy-duty-gara ... vt/161200/ works well but its much cheaper at "Range" or B&Q. I've fitted around my doors and the improvement's been really noticeable.
Regards, MikeN.

[Oldmogman]

Thanks Mike - I'd spied the same polystyrene panels and was going to sandwich them between the wall and the 6mm ply!

Fortunately, my up-and-over is wood, which must help matters.

I think I'll try insulating the walls as above, then experimenting with ventilation/no ventilation to see which is best.

Reckon my next house will either have to have the garage attached or have space for a separate wooden one - with plenty of romm for 'toy' storage and play area for me to work on it in the winter...

[philthehill]

The rain here in the Test Valley (lower down the valley than Hurstbourne Tarrant) has at times been so hard that it has driven through the wooden walls of the shed where I have some power tools. The walls and roof are good and all joints sealed and the wood treated with wood sealer/water proofer. Thankfully for the past few days I have been able to have the shed door open to dry out the inside and have a good circulation of air . Now if I had had it insulated and an inner wall fitted I would not have known that the water had been driven through and the wood would have started to rot. So it is not always best to have the insulation in place. Everything bit of metal bare (which was covered in grease) or otherwise now covered in WD40 so hope fully it will be ok.

[les]

Think we're only talking about concrete of brick where insulation might be of some help.

[bmcecosse]

There is no point in 'insulation' unless you have a heat source inside the garage - and wish to stop the heat escaping. Otherwise - no matter how thick the insulation - the temperature inside will equal that outside.

[MarkyB]

Insulation will make it a much more pleasant building to use, cooler in summer and warmer in winter.

[bmcecosse]

Indeed - but only if there is a heat source in winter....

[MarkyB]

Not warm, just warmer than outside.
Shouldn't need air-con in the summer either

[rayofleamington]

Ventilation just brings in more moisture!

yes and no.
If you completely seal a garage, then there's nowhere for the moisture that is on & in a car to go, so it stays there.

As air temperature falls, the relative humidity rises and you hit dew point and get condensation (e.g. evenings)
During mornings air temperature rises, and increased ventilation will remove water deposits.

Therefore evenings you want to limit air flow in evenings and mornings you want to have air flow (unless it's foggy..)

Insulating a garage and then adding permanent ventilation holes would be pretty self-defeating.

If you run a dehumidifier, the most energy efficient way is to have the garage well sealed and only run it after putting the car in and for a brief period after sunset each day.

Running a dehumidifier in a ventilated garage is rather like running a car with the air con on full and opening a window.

Just my 2ps worth for what it's worth - not wanting to advocate energy wastage. ;-)

[moggiethouable]

This will tickle you.
http://www.oldclassiccar.co.uk/engineheater.htm
Ah, happy days.

[MarkyB]

The problem with paraffin is the amount of water vapour it gives off

[Roger46]

Alas, Oldmogman, the trouble is the weather. In winter we get cold snaps which are dry (below freezing, air holds little water) interspersed with mild wet weather, often stormy, in which the humidity is high. So your garage gets cooled down in the frost only to be hit by mild damp intervals when the damp air gets into your garage and cause condensation on everything. If you're lucky and your garage is attached or built into your house you've no problem - its always just warmed enough to keep it dry. But separated, its real problem. (Especially for me 'cos I live in a frost pocket - we had minus 15C one night last winter.)

I think you need to minimise ventilation and only open it up on dry days and insulate as best you can. Don't what ever you do open it up or ventilate on warm moist days after a frost. Keep a cheap thermometer in there to check that the garage is warmer than the outside before you open up. And if you can add a little heat then so much the better. Regards, MikeN.

I agree entirely during very cold spells the air holds zero or close to zero water vapour but when warm air holding some water vapour then hits your very cold car it will condense onto it. Insulating the garage will prevent the sun from warming it an thus exacerbating the situation.

Ventilation works in domestic situations because the internal space is heated and occupancy generates humidity that needs to escape from the dwelling!

There are two solutions 1. Minimise air movement and add a very small heater under your car, or 2. Eliminate air movement as far as possible and install a dehumidifier.

[Roger46]

I agree you must avoid Pravin (and bottled gas) for heating because of condensation. These make good garage heaters -

http://www.ebay.co.uk/itm/Electric-Tubu ... 27c22cca27

Or just search tubular heaters !

[MarkyB]

Ventilation is good for drying things, ask your Mrs what the best kind of day to dry clothes, it's one with plenty of air movement.

[Trickydicky]

Maybe when we get the benefits of all that shale gas we are standing on I will be able to afford to heat the garage

[Roger46]

Ventilation is good for drying things, ask your Mrs what the best kind of day to dry clothes, it's one with plenty of air movement.

Only when the air isn't saturated with water! People don't dry clothes outside in the winter they just hang there wet!

[MarkyB]

When the air is 100% saturated with water vapour there will be a dynamic equilibrium where as much water condenses out of the air onto the clothes, as evaporates from the clothes into the air. If humidity is less than 100%, then there will be more evaporation than condensation and the clothes will become drier.

If the humidity is very low, either because the air is hot and can hold more water, or because there is just very little moisture in it, then the evaporation will proceed more quickly. If there is a wind this will speed the drying up because 'fresh' air, with low humidity is constantly passing over the clothes.


When drying clothes there comes a time when it's going to be faster to dry them indoors, not an option when drying a car