Why Heat the Shop?

A start-up furniture maker hears about ten reasons not to work in an unheated garage during the winter. August 21, 2006

I am a newbie to the furniture business but was fortunate to have a small partnership with a retail store that has agreed to purchase several of our pieces. My partner (who professionally paints our furniture) and I expect that we will get additional orders through the winter. I have a woodworking shop in my unheated garage. I live in Iowa. What problems will I have or have to look out for when I make additional furniture pieces this winter, concerning gluing, expansion and contraction? Do I need to insulate and heat the garage? Can you make quality, sound furniture without a heated garage? My partner has a heated garage so painting is not an issue for her but her shop cannot be used for woodworking.

Forum Responses
(Furnituremaking Forum)
From contributor A:
Yes, you should heat and insulate your garage. The issue with dealing with wood movement is not so much the temperature as it is changes in humidity. In an uninsulated shop you will have absolutely no control over the humidity levels of the garage. After a week of cold weather, the cement floor will gradually become cold. Introduce an unusually mild day and your floor will condensate and you will discover rust on your equipment and radical wood movement. You will need to have some heat just to accommodate basic glue ups and to reduce the wear and tear on your equipment. I own and operate a cabinet/furniture shop on a part time basis and I heat the shop at the lowest possible setting when I am working in the field. When I am using the shop, I heat to where it’s comfortable for working. If I am preparing to finish, I'll warm the room up and let my projects acclimate to a temperature that is acceptable for finishing.

From contributor B:
Your questions raise a number of issues that will affect your ability to produce quality work over the winter. Here in N. California our temperatures go from 60 degree days to 35 degree nights in a typical year, and I'm sure yours are colder. First considerations are the manufacturers’ recommended temperature ranges for their products - glue, stains and topcoats. Going below these is inviting serious trouble in the long term from material failure, and dealing with the short term hassles that come from the products becoming unworkable. Most (I would say all, but I'm not a chemist) adhesives and finishing materials that we use have specific windows of temperature in which they work well. My experience is that when you push those limits the process and the results get very frustrating. The object is to get your shop, or part of it, to the temperature that you need for the time it takes for the materials to cure.

My shop is a cement floor, stud wall, aluminum roof building of just under 1200 square feet. Our summers are very warm but dry, so it works fine half the year. When the temperature drops, I'm in trouble! What I've done is to screw 1-1/2” styrofoam panels to the rafters in about a third of the space and drop heavy plastic partitions from the rafters to the floor to enclose a room. Spring clamps close the seams where I want to enter or access stuff behind the plastic.

This area has become my winter assembly and finishing space. Heat is provided by a couple of Halogen lightstands with four 300W bulbs each - inexpensive and portable, plus a propane Mr. Heater for really cold days when I'm not using volatile solvents in my winter world. It's not the ideal setup, but it does work very well for now. It enables me to be productive during the colder times of the year when weather would normally shut me down.

A couple of quick thoughts: you are better off keeping your material in the place where you will be working from rough to finished dimensions. Moving it from one temperature and humidity situation to another is likely to cause problems. Once everything is glued and screwed, taking it someplace else with similar temperature and humidity for finishing is not too much of a reach.

From contributor C:
Where I am it is pretty cold 3 to 4 months of the year. I don't find that expansion and contraction is a problem, however gluing and finishing are. Even if your shop is at the correct temperature, if the timber has been left in a very cold shop for a couple of days it takes time to warm it up. Glue joints can chill and fail (white PVA glues dry to a chalky white color rather than clear and fail easily - I believe that this is called "chalking") so it becomes essential to keep the ambient temperature of the shop a few degrees above this chill point, even at night. Your glues will also suffer in extremely cold conditions - frost destroys PVAs, yellow glues and many PU glues. And in cold shops glue sets much slower, too, if at all.

I'd second the advice about what can happen with a concrete floor, but I'd also say that working in a very cold shop can be bad for your own safety/health - from experience it isn't pleasant to spend a day machining cold timber on ice-cold cast iron machines, and freezing cold concrete floors will continue chilling your feet many hours after you've turned on the heating. Sort of comes right through your boots and socks.

From contributor D:
Do yourself a favor and heat your entire shop. A one or two car garage space is not all that big. The safety thing is the number one issue. Once you solve that you have solved all the others.

You have cold fingers, cold feet, cold steel machinery, cold wind from that machinery, cold hand tools, cold clamps, cold wood, etc. How can you work comfortably, accurately and safely?

Heat is a cost of your business overhead. Plan on it. Your finisher obviously has. What you spend on heat will save you in trouble and aggravation.

From contributor E:
Just a guess, but I am thinking that you are going to be building out of pine and do that painted distressed thing. As a one time resident of Iowa, I know how cold it can get and you will just be wasting money and effort trying to build anything type of furniture out of pine in that winter. You have to maintain some amount of heat around the clock. If you are going to be getting your pine from a home center/average lumber yard you have realize that that wood isn't anywhere close to dry. The freezing cycle that your wood will go through will cause tremendous amounts of problems from warping, cracking, and tremendous amounts of movement - everything that a piece of wood can do and more. Get some heat or wait till April. But then again when I lived there, it snowed 10 inches in April. How about building a bunch of stuff in June and July?

From contributor F:
I went through the same issues a couple of years ago. My suggestions are to: 1) seal your concrete floor to discourage moisture from wicking up through it. 2) Insulate all of the walls and ceiling. 3) Buy a $25 humistat at Radio Shack to know what your relative humidity is and balance to your indoor by 4) Installing a portable de-humidifier. 5) Install an electric heater/cooler system. They run about $600 and can heat and cool a double car garage easily. Going with electric eliminates open flame issues. It is a comfortable/controlled environment year round and my wood movement is consistent with my surroundings in most homes.

From the original questioner:
I think the best option may be something other than an open flame. Is natuaral gas considered an open flame or should I just use electric? I have a 3 car garage where I work. Also, I hear a lot about radiant heaters (ceramic?), any thoughts on those? Thank you for all of your advice.

From contributor G:
Well it is -10 below F this am as I sit and read this article. I am a small furniture shop in Alaska. I like to read this forum before I go out to my nice, warm, shop. All of the advice that has been given to you is right on the money. Natural gas is considered open flame. If you plan on spraying lacquers or solvent based products, you will want to stay away from open flame heat.

Insulate, wire it, put in good lighting, heat it, and install a suitable dust collection system. Then on mornings when it is -40 below, you still do not hesitate to head out to the shop to do what you love to do.

From contributor H:
One thing often overlooked is humidification during winder months. I've seen wood twist, warp and generally cause issues when something comes into too dry a space. Luckily it wasn't in my workspace but I've had to repair some of this type damage before that was brought to me. A humidifier is cheap insurance in addition to heating your space.