When I am not out auditing homes, or working with builders on Energy Star New Homes, I enjoy Woodturning! Making a bowl or other turned object is fascinating; it takes my mind from serious things and to important things. It lowers my blood pressure!
I have been using my garage to work with my lathe and the wood! It keeps my head from getting sunburned, and keeps the sun and weather off the wood waiting to be turned. My. attached garage is 57 years old. The common wall between the garage had unsealed drywall on the garage side! The exterior walls are open studs. The house is old enough the wall and roof sheathing is 1x material. You could see the boards that were used to form the basement walls. That is one form of recycling!
The use of 1x material, despite the recycling, is not the most green approach that could have been used. The garage has not really been usable in the cold, so 4-5 months are lost. I have tried various types of heating to allow work to proceed. It works with warmer, less windy days. This is Kansas and there aren’t many of those!
One of the personal goals involved in my becoming an energy auditor was to learn how to make my shop workable 12 months a year. My study of insulation types, heat loss, installation methods and costs, all applied to my quest!
I looked at installing Fiberglass Batts, inexpensive. I thought about adding rigid foam, also inexpensive. I could do the labor on each of these. Each of those would require a covering, at least for physical protection of the insulation, and ignition protection of the rigid foam. The same problem, of a protective covering would apply to blown in rock wool, fiberglass or cellulose. And yes, I could do those or contract them out.
Each of these choices must also have the insulation in contact with the Air Barrier, to work at the rated R-Value. In our climate zone, the air barrier is the lath and plaster, or drywall.
The other option, slightly more expensive than the others is commercial 2 part Closed Cell Spray Foam. This product at 1 inch thickness provides an air barrier. The manufacturer’s material shows R-6.5 per inch. So 2 ½ inches is about R-15. And the air barrier and the thermal barrier are in contact thus forming a valid thermal envelope. The underside of the roof deck and the walls could be done. The actual time to install would be less than one working day.
So one March 1, the Foam Installer was here and sprayed the foam. Following the weather in March we had several days the low temperature was in the 30s, with highs in the 50’s or 60’s. By April the lows moved into the high 40s and 50s.
Now it is July and we have had highs in the triple digits or close for about three weeks. Lows in the 70’s, a few 80s and high 60s.
How is the insulation performing?
The temperature in March never dropped below 50 degrees, even on the days with a low of 35. One night I left a window open and the low of 40 did not drop the temperature below 55 after a 65 degree high. That seems very satisfactory to me.
Since our high temperatures hit the 90s and then into the triple digits, I have observed a 5 – 10 degree delay in the temperature inside the garage. I don’t have any AC there. So a 103 degree day like today, the temperature in the Garage was 93.
I have two fans to create air movement. One is a squirrel cage fan I purchased at a garage sale. The other is a box fan. I also can turn on the air cleaner hanging from the ceiling and it will move air around the garage. Use of the fans with doors and windows providing a source of air movement have made those triple digit days seem much more like 80 in the shop.
My choice to insulate my garage for use as a shop was not simply based on this type or that type of insulation. It was based on how the wall would work with an air barrier and a thermal barrier in contact.
I could have used: Fiberglass, Rockwool or Cellulose with drywall covering. The time involved with any of these would work using a contractor or doing it myself and would have taken several days to a week. Going the Closed Cell Spray Foam approach took less than a day, and I was done.
When winter comes, as it always does, I will watch and comment again. The old furnace is now installed in the attic of the garage to kick on if the temperature drops below 40 degrees.
One goal is to have a shop that is warm enough to work in all year round. Another is to keep the shop equipment above Dew Point. That is the temperature when the humidity begins to condense on cold objects. In the summer we think of our cold beverages sweating . Today the Dew Point was 59 degrees and any cold beverage, including tap water is colder than that. If the temperature of the equipment goes below dew point, the condensation will cause rust.
Rust on the shiny steel of the saws or the lathe is not good. So here is to keeping the shop above the dew point, and your cold beverage below dew point.
Cheers!
