Workshop Humidity at 40%-55%

[onlinename]

Hey guys,

So I am renting a shed in Kent as a workshop, it's quite small, has a double glazed entrance door and the landlord put some insulation over the wood and covered it with plasterboard.

The floor is bare concrete and I will try to put some 3"x1" on it and then some insulation from Wikes called T & G Chipboard Flooring 18x600x2400mm

Is there anything else I can do without the use of a de-humidifier to reduce the humidity? and do you reckon that the floor improvement will make a difference?

Also what is the norm for workshops like this? 50% seems a little too high..

Thanks for any advice!

 

[Sgian Dubh]

50% RH is about in the middle of the seasonal range wood will experience in reasonably well insulated and heated occupied buildings, eg, houses, offices, hotels, retail outlets, conference centres, etc, so for artefacts destined for these environments you'd be about right, and quite a bit out for artefacts destined for exterior environments, eg, garden benches, tables, etc. A typical house in the UK ranges between about 25- 40% RH in winter to about 60-70% RH in summer. You'll find your shed or workshop will follow seasonal patterns too, but what they'll be will depend on how well it's insulated, how well it's set up to exclude moisture (eg, through the floor, walls and roof) and how you control the climate, ie, heating and cooling. Slainte.

 

[Muswell]

I don't think I have ever got down to 25% in my house, I find a typical range is 50 - 65% with a few exceptions. I run a dehumidifier to keep to 55% for making instruments and nothing has ever cracked subsequently ( that's done it! ).

I had my workshop in a small room in my house and I had to run the dehumidifer a lot and I think that was mainly due to the moisture I was sweating and breathing out because when I moved to a room with 2.5 times the volume in the same house I hardly ran it at all.

50% is fine IMO

 

[Sgian Dubh]

I don't think I have ever got down to 25% in my house...

The fact that you've never seen 25% RH in your house will depend on factors I listed in my first post, eg, insulation, temperature you maintain in your house (and even the source of the heat) and things like if you have single or double glazing, etc. But 25% isn't out of the bounds of normal for some houses in cold dry winters, if they're well insulated and heated. For instance, the house I live in sometimes gets a low as 25% RH during the winter, but typically hovers around 35- 45% during most of the winter months. I derived these figures from monitoring RH in the houses I've lived in over several years, but there are also records available from other sources indicating typical RH conditions to be found in habitable buildings here in the UK and elsewhere in the world.

So, you're not wrong to report the sort of numbers you experience in your house; your numbers simply fit within what I consider to be the normal range. Slainte.

 

[onlinename]

So this might be a dumb question but how do you deal with things like 1-3mm ply bending all the time? Typically I know ply is screwed or glued onto something else but anything veneerwise or 1-3mm bends quite a bit when it gets in the shop..

 

[Muswell]

Well, I have some 1.5 mm ply which has been in my workshop for some months with no humidity control and it stays flat. It is stored so that air can get to both sides. I remember some years back planing and scraping some guitar ribs down to 2mm then leaving them flat on the bench. Humidity changed overnight and they bent, but came back after the air got to both sides. Maybe mine is a better quality ply, it is model-making ply.

 

[onlinename]

and what about workshop tools, does the humidity not affect them? I just bought a dewalt table saw and my biggest paranoia is rust. Not just for the saw but for all my tools in general. Is there anything I can do to protect them? I have noticed my screwdriver heads are the first to start suffering..

 

[Phil Pascoe]

The humidity in my workshop varies between 60% - 75% in winter to 80% - 90% in summer. The only time I have a problem is if I heat it in the winter - then the condensation starts. Other than that it's not a problem with tools - I don't do much joinery that would be affected, and in any case my house isn't that much lower. One thing I do do is keep my augers in a bowl of diesel - they rust like anchors otherwise.

 

[Muswell]

and what about workshop tools, does the humidity not affect them? I just bought a dewalt table saw and my biggest paranoia is rust. Not just for the saw but for all my tools in general. Is there anything I can do to protect them? I have noticed my screwdriver heads are the first to start suffering..

My workshop is within the house so stays quite warm and I get no problems. You get condensation when air comes in contact with surfaces at or below the dew point, which is the temperature at which the humidity has gone up to 100%. You have to either reduce the humidity or raise the temperature to avoid condensation. Or you can wipe everything with camelia oil.

 

[PerranOak]

Wow! I would sell my dear Aunt Fanny for humidity as low as that!

Here in Cornwall, I get 95% humidity in all but the summer months. Everything less than than 9mm bends up and/or goes mouldy. Tools have be be wiped with camelia oil evey single use. My Sjoberg workbench top could be used as a form for voilin backs!

Come on summer!

 

[newt]

Interesting, humidity in our living room is about 15% we have an humidifier and that brings it up to around 30%. 15% we find very uncomfortable particularly on the respiratory system. It's a bungalow, double glazed, open chimney in living room, central heating radiators.