Friday, May 27, 2011


Big ones! It is two-thirty in the morning and I have just discovered them. I though that the first one that crawled into bed with me must have just been lost, but with the second through tenth ant, I realized I had an infestation. When I moved into my house on that rainy night in March I had just thrown two sheets of plywood on the loft joists without cutting them to size. They overlap eachother leaving a small space along the joint under the mattress. This is where the ants have taken up residency. I think that they like the warmth and moisture under the mattress from my formerly sleeping body. It looks like tommorrow I will be cutting the plywood to fit properly and figuring out a way to make an airspace under the mattress. Enjoy the night ants, because it will be the last in my house! Now to try to get some sleep...

Wednesday, May 11, 2011

Wool insulation?

A couple of people responded suggesting sheep's wool insulation. I had looked into this briefly a while back, but dropped it early on because I thought it would be too expensive. I took another look at a company called Oregon Shepherd, in Portland Oregon. It seems like wool will actually be cheaper than using EPS, will not settle and will still be extremely light. This website also claims that the wool will resist mold and mildew. Oregon Shepherd claims around R-4 per inch, which is slightly better than cellulose, and not far behind EPS. Sounds good to me. My one complaint is that there is not very much technical information on their website. I will call them tomorrow with some more questions though.

Tuesday, May 10, 2011

More ideas on insulation
Thanks to a comment on the previous post, I am thinking about natural fiber and clay infill again for my walls. I dropped the idea a while ago due to weight concerns, but now I am back onto it. One advantage is that I would have a very high thermal mass in the walls which would help me regulate the temperature. My little stove will put out plenty of heat, but it would be nice if the heat would stick around over night so I don't need to feed the stove every four hours. Once these walls heat up they will keep radiating the heat throughout the night. Another benefit is that it will do a much better job of regulating the moisture in the house- a necessity in a place this size. Imagine what a pot of boiling pasta water could do, even with a vent over the range.

The basics of clay/fiber infill systems are not complicated. You basically coat woodchips or straw in a fine clay slip, then pour this slurry into the wall. Once it dries it provides decent insulation and some more structural integrity (which I definitely don't need). The clay regulates moisture eliminating the need for vapor barriers. From what I have read, I expect about R-2 per inch, which is not much but the thermal mass will work to my advantage. This would also be a good base for a plater finish on my walls. I already salvaged a pile of wooden lath from a renovation down the road a few weeks ago. I still need to take a good look at the weight issue if this house is going to be mobile though.

Here is a link to the Fox Maple School (where I had my first timber framing experience) article on woodchip and clay infill.

Monday, May 9, 2011

Insulation investigation

Incredible sunset outside the shop last night

Today is one of the nicest days of the year. It is sunny, clear and warm out but somehow I find myself stuck inside on the computer researching insulation. I should have done this on one of those cold sloppy winter days. Oh well. They say you are not supposed to go grocery shopping when you're hungry, right?

Basically, I am ready to put my roof together. The 2x4 framing is finished, the paneling is back-primed and the sheathing is neatly stacked. All I need now is to pack the framing with some sort of insulation before I nail everything together. Last night I calculated the amount of insulation I will need. I have not done a good though comparison of different types of insulation yet, but my original thoughts were to use blown in cellulose. I want to avoid fiberglass for health/sustainability reasons. Cellulose is recycled, will fit all of my odd sized cavities and has a good R value. For the roof however, I need something lighter so that the panels will be a manageable weight. My first thought is to use EPS insulation (rigid boards of polystyrene, like foam cups). It is light, air tight an has an excellent R-value.  It may not be the most sustainable option, but it might be a reasonable compromise. The last one I am considering, which might work for the walls and roof, is spray on expanding polyurethane foam. It can be made with soy oil rather than petroleum and supposedly has no VOCs when it is cured. This is important for me, especially in a space as small as mine. There is no Formaldehyde in my house yet! Spray foam does have the best performance characteristics but with that comes the price.

That is what I am considering, but I would love to hear of other options that you might know of. It is far too nice out for me to be inside any longer, so the research will have to wait for another day! I'm off to caulk the siding joints finally.