More or less on topic in here, I guess...

Over the next few months I'll be moving everything into the garage at my fiances house as we're selling mine. On the whole, this is a good thing and one of the reasons for keeping her place - it's bigger and detached, at the back of the house opening onto a securely gated lane. Or to put it another way it gives me somewhere to retreat to when I've upset her for some unknown reason!

There's only really one problem with it as a workshop (well, two - it's not very secure, but I can sort that), which is that it's a bit damp. Mainly this is because of poor drainage at the back where it opens onto the lane, which is going to involve some hard graft, hardcore and maybe some drainage channels. However, it's also not heated in anyway, which I'm thinking is going to be a bit of a problem with all my tools in there, particularly the woodworking ones.

What have you done to solve this problem? I was wondering about something like a small oil burning stove running on biodiesel, partly because I've still got 80l of crappy biodiesel that I syphoned out of the Discovery before christmas , but I'm open to any and all ideas. It doesn't need to be particularly powerful - it would be nice if it could warm the place up in the winter, but it only needs to keep the damp off and be reasonably cheap to run.

I'm in Birmingham, in a smokeless zone, so a smoke belching waste oil burner is probably out!

The garage isn't insulated, which won't help, but it's probably not economical to do anything about this, barring potentially strapping loft insulation up under the roof.

If you can get power to it then how about a couple of low power electric heaters. I have a 500w oil radiator in my workshop that is only on its lowest setting for the colder months and timed for nights. it would be a good start until something better comes to mind. Good ventillation will also help clear any dampness and you could line the walls and ceiling with insulation panels from your local diy shed.

It has power, though that's another thing I need to investigate as I'm not sure how good it is. It's got its own circuit breaker in the house, so it's at least not a spur off the downstairs ring main. There's just a single double socket, though, in a really inconvenient place, and the light is plugged into it too.

Heating a damp area is almost totally pointless, all you end up with is warm damp instead of cold damp.
As warm air will hold more moisture than cold air you actually make the damp problem worse.

A bog standard domestic Dehumidifier, from the sheds, is the start of the answer. These draw air in the back and blow it out of the front. Mount the dehimidifier on a shelf, as high up the wall as possible. Orientate the D so it is side on to the wall, that way neither the entry or the exit air flow is compromised.
The height improves the efficiency, as the air is slightly warmer, and warm air contains more moisture, so more can be extracted. Also the blown air covers a greater volume (than if the unit was floor mounted) which again increases it's effectiveness.

Power consumption is probably less than 100W, although I'd estimate that for the first 6 months it will be on 24/7.

Obviously insulate the roof, but as far as heating is concerned, I prefer a fan assisted convector heater. Again these are cheap from Argos etc, and again I prefer to wall mount this as I feels this benefits circulating the air.

This topic has been covered before, and on every occasion I have contributed I've mention the D word, so I suggest a search on that.
Mind you, my earlier contributions mayhave been in other forums, not this one :-)

HTH

Put your foot down and insist your tools are stored in the house.

If you go for a dehumidifier then make sure you get one suitable for use in garages/sheds as the normal household ones will freeze up if they are used below about 10°C.

I'll take a look at dehumidifiers - sounds like a reasonable solution.



I've already been told the engine can't stay in the loft

Although if I moved all her books to the garage there might be space...

get one of these clicky!

they are really good, and you can run them on diesel/biodiesel/central heating oil/cookin oil theyre cheap to run and pump out some mega heat, and soon dry things out.

ive got the 28kW one in a 60 X 20 X 25 workshop and its makes it toasty in those winter months.

you really are best to tackle it at source.

make sure all the walls are free from earth, debris etc. as far down as possible and make sure you dont have any air bricks covered up.

you don't mention what construction the garage is, but i'm assuming brick. if it does not have any ventilation i would recommend getting busy with the drill and making some. check out the local building regs, they'll give you guides on ventilation area vs. floor area.

1/2 the trick is to stop condensation.

This means any heat really should be DRY heat, space heaters tend to make it warm - but everything then gets hanging in condensatoion.

There are a number of things you can do which help.

1 When its dry inside and out (summertime) paint the outside of the walls with thjompsons water seal, 3x coats and loads of it, thjis does make a huge difference and forms a waterproof membrane of the outerbrick work.

2 Clean the floor, then paint it with a Workshop floor sealant and paint, also means much easier to keep clean, but stops the damp coming up

3 Check if you have a DPC course in the walls, this is nornmally a blacl bitumen seal running close to the ground, if you have one ensure the earth is lower by 2-3 bricks then the course, if the earth is close or higher than the DPC this causes damp probs.

4. On the sunny days have the doors open to let air in, and if you do decide to heat then dry heat sunch as oil filled radiators etc a far better than a space heater which causes the problem to be worse. Infra red heaters are also good for dry air, as is a dehumidifier which is designed to do ezaxtly that

HTH

Nige

some guys on here were discussing putting a homemade woodburner outside the workshop and plumbing house radiators into it with a central heating pump (like house heating but a la scrapyard)

If you get a dehumidifier (wise) try to get one with a pipe outlet not a tank (you'll be emptying it every 2 hours if ur wshop is wet )

also its not too much hassle to double skin a workshop and insulate it if your racking it out with shelves its all one job (can hide cables at the same time) then it will be toasty (mine is an oven in the summer)

Have you thought about putting a roof on it, Geoff ?

Mo

The thing with dampness is that if you apply a little heat then the dampness becomes vapour and raises the humidity. Then, given better ventillation, the moist, humid air can be removed from the garage and replaced with cooler, dryer air. Insulation also reduces cold surfaces that allow moisture in the air to condense.

If the garage is just too damp then one thing to do would be to keep all the tools stored in a cupboard that is warmed and ventillated so that moisture won't condense on the tools and metal work but elsewhere.

Good call.
Watched 'A plane is born' and they used a similar cupboard to store the GF matt and resin. Consisted of said cupboard with well fitting door and two 60watt light bulbs to produce the warmth.

Steve

Put the shiny chrome spanners and sockets in the cutlery drawer - they will blend easily

Ditto all above about condensation - Keeping the outside walls dry right down to the ground with good through flow ventilation is the key to my old pre-fab concrete double garage. The only time i get condensation is when there is a sudden temperature rise after a long cold spell - happens once or twice a year when everything drips for a few hours but because it is so well ventilated it dries out naturally.

My tools havnt rusted as they are stored in tool drawers (steel) but because they are closed dont seem to get condensated.

It's a prefab concrete jobby, straight onto a concrete base. It doesn't have a dampproof course.



The roof is one thing that doesn't need attention - it's got a good tiled and felt lined roof that's only a few years old. Not insulated, but otherwise as good as you could ask for.

Job number one is going to be to sort out the drainage at the back - the real problem is that the base is built level with the ground, which slopes down from the track which in turn is more like a stream in heavy rain. The area in between the garage and track is mostly just soil (I thought it would be soil on top of hardcore, but I've been digging holes and it isn't, which at least makes digging it out easier). On the plus side the hole I left didn't fill up with water when it rained for a couple of days, just got a bit soggy in the bottom, so drainage isn't too terrible.

The proper solution would be to dismantle the garage, add a new concrete slab on top of the existing base with a dampproof course under it then reassemble on that. The next door neighbours are in fact about to do exactly this, but with a new garage. However, we're only planning on staying here for a couple of years so I can't justify the cost. Neither could I get it done in the two free weekends I have before moving everything from my house in august...

What I can do is dig out all the mud and fill the area with ballast so it drains better, hopefully with a soakaway under it too. I think I may need to build a concrete ramp in front and extending just inside the doors to get the slope in the right direction, but we'll see if the ballast works by itself first.

Then there are dehumidifiers - I've found a few but I've no experience of these beasties. Is anyone familiar with or have views on any of these?

Portable Dehumidifier (no name)
General Electric DRY-C20
Prem-I-Air XDRY
Mitsubishi MJ-E16V

can you jack up the garage section by section adding a damp course as you go round?

don't forget to put in vents. good ones too so that air has a good path to enter and exit. natural ventilation is your friend. what you've suggested sounds good, cut earth away as far as possible, down so that the concrete base is exposed would be good. when you put your gravel in, make usre it doesn't go above the level of the base so that air is free to move around and dry the concrete sectional panels.

if your natural ventilation is good enough, you should be able to get away without the need for dehumidification.

good luck

The panels that form the walls sit straight on top of the base, so no, the only way to add a dampproof course would be lay it across the whole floor then flow another concrete slab on top of it and reassemble the walls on that.


I think the ventilation is actually okay - it dries out during periods without rain. The problem seems to be mainly water ingress round the doors due to poor drainage/the lie of the land.

Looks very much like the one I have and about what I paid (from a differnt supplier who I forget). Had it about 8 months now and it works fine so far. Been used in garage and also in camper van/caravan. In the garage it will easily fill the 'bucket' in 24 hours if the weather is slightly damp. In nice weather it can take a couple of days to fill up. Biggest problem is having to keep emptying it.

It does say it can be plumbed in instead of using the tank - I didn't include anything on the shortlist that didn't have a continuous drain option.

That's a plus - I was expecting to be told only the more expensive options were up to the job

The dehumidifier we have on the boat has a short length of garden hose from the outlet point where the condensate comes out to stop it filling the tank and vent through the sink.

A longer length of hose attached to the dehumidifier, which reaches outside you garage would stop the having to empty it.

Do keep an eye on it as some dehumidifiers have been known to set themselves alight.

Martin

Mark, does this dehumidifier have a moisture sensor (ie. can be set to switch on automatically when it's needed) or does it just have a 'power' setting? I'm thinking I'll spend enough to have a system that essentially looks after itself day to day.

So far looks like the earth works at the back of the garage are keeping the worst of the water out. It was damp in the corner again yesterday, but I can't see any sign that the waters been up over the rubble outside so I think that's just what drove in under the door and wall. That I can sort.

From the sounds of it, even with a moisture sensor it would be probably run most of the time, why not put it on a cheap mechanical timer, to come on three times a day for a couple of hours a time?

The garage dries out fine during sunny periods, so no, it doesn't need to run all the time.

Hi Geoff,

I give all my tools a liberal spray of WD40 before they go back in their draws/cases if I have been working in the damp or wet.

I know its common sense but worth giving all your tools a spray until you get the garage sorted.

........I will get my coat if that sounded patronising.....

Cheers

G

Thankfully the tools aren't in the garage yet, they're still at my house (which we're selling), so I have the luxury of sorting this out before moving them. Not all my tools lend themselves to this treatment - it isn't really practical to WD-40 the whole bandsaw after every use, for instance (and I really don't fancy digging damp sawdust out of it, so it'd need hoovering out, too...).

Are you sure it gets fully dry? It's surprising how much moisture is still about even when you think it is dry, but I know what you mean, can't really think of any other way if it doesn't do it itself

I'm sure it's not, and I'm equally sure my current garage isn't 100% moisture free. That's not what I'm aiming for.

You do realise that it would be a major undertaking to remove all moisture from a building (any building, never mind a garage with no damp proof course), and that it probably wouldn't be very good for the building anyway...?

Yes, and I don't think you'd ever do that with a cheap de-humidifier. What I was suggesting was running it on a timer so that it comes on every day for a few hours at set intervals.

You would never get to the point where you would remove all moisture, and it would be better than running it 24/7

My in-laws have a similar size one in their living room (country house) and even in the summer it can easily empty a few full loads.

It was only a suggestion though

I believe it has a moisture sensor. It has a 'normal' which is supposed to maintain an ideal humidity for in a house. It has a 'max' setting which I runs 24/7. Or the dial can be set anywhere from max through to low via normal.

On 'normal' in my garage it seems to run most (if not all) the time as it's not very well sealed and has a bit of air flow so I'm essenitally trying to dry the whole world But in the back of my van it kicks in and out as required when on 'normal'.

Sounds like it'll do the job, then

Just got to liberate the funds from SWMBO...

Got a one of these, as recommended by Mark, a few weeks ago. Along with the earth works outside that have stopped water running through the garage in heavy rain , it's done the trick nicely. I haven't plumbed it in yet so emptying it is a bit of a PITA (on a really wet day it can fill its tank in about 12 hours), but that will be sorted soon. Just got to finish boarding up the hole in the side where I removed a rotten window (that isn't helping keep the moisture out!) and replace the other rotten window that doesn't face the side of the next door neighbour's garage.

Next door are having their garage demolished and rebuilt on a raised base next month, so I'm going to speak to their builders and see what it would cost to get the floor raised inside mine over a dampproof course while they're here anyway. I'm happy enough with it as it is, though, so I'm only doing that if it's fairly cheap.