Rigid foam insulation against lathe / canvas

[Jafo]

Yeah, you are going to want to be able to open the

dome

. It is basically the #1 way to vent the yurt and venting is basically required, unless you want to do some through-the-wall fan like a bathroom might have..

[willothenorth]

For anyone following this or wondering about how rigid foam might work for them... A few years later. I utilized a lot of wisdom and advice from folks here, particularly keeping in mind the need for venting upwards. I started by installing the rigid foam behind about a 4th of the diameter and then checking on it rigorously through summer and winter. I never found any

moisture

issues ever. Feeling pretty assured, I completed the rigid foam installation around the complete diameter. This made a massive difference in being able to heat and maintain heat. I heated primarily with the Toyo (oil) stove mentioned above and was able to maintain 50 degrees (or higher if I wanted) with ease (but also a lot of oil, because it's still in progress!). I am about a quarter of the way through adding the second layer of insulation-- Originally that was going to be fiberglass, which some of it is, but I am also experimenting with recycling water bottles into

insulation

. I ended up angling towards using wood / vinyl flooring as my siding, because I had an excess, and it turned out to look kind of cool. This project is happening bit by bit out of pocket so it'll take some time.

The stove the original owner had was a Fisher that had been on our property that they cleaned up. There was a few issues with it. Someone had welded a badly made flue collar on top that was cracking. I replaced that with a new flue collar. After at least 2 years of research, I last month cut into my roof and installed the stove pipe. Thank god it turned out awesome and the woodstove works great with proper draw and can heat the yurt up fast. I'm going to post about that somewhere else.

I do still use a de-humidifier, especially in the summer.

I ended up having two installed windows and in the summer will have both my doors open with screens over them.

I am going to install a vent system specifically for shop stuff, mainly welding.

If you are thinking about using rigid foam

insulation

, I think it works. Remember that it needs to be continuous. Again, Fairbanks climate is fairly dry. I connected the foam boards together where they met with spray foam, and did spray foam at the bottoms of them, but did not seal the top part of the foam boards, based on the advice of this thread, so that the air behind them could vent upwards. That seems to really be the ticket.

Rigid foam board is really meant to go on the exterior of a structure. I think you might be able to attach 1" foam board under the awning of the roof. Most places want vapor barrier closer to outside, so for most places the rigid foam board being outside (with its foil siding as a vapor barrier) is ideal. For extreme cold climates (here) you want the vapor barrier closer to inside. I'm continuing to research how layers of vapor barrier interact. Always a learning experience.

[Bob Rowlands]

Wow! Great update. Thanks!

[Jafo]

Good stuff!

[aspegicus]

Originally Posted by willothenorth

For anyone following this or wondering about how rigid foam might work for them... A few years later. I utilized a lot of wisdom and advice from folks here, particularly keeping in mind the need for venting upwards. I started by installing the rigid foam behind about a 4th of the diameter and then checking on it rigorously through summer and winter. I never found any

moisture

issues ever. Feeling pretty assured, I completed the rigid foam installation around the complete diameter. This made a massive difference in being able to heat and maintain heat. I heated primarily with the Toyo (oil) stove mentioned above and was able to maintain 50 degrees (or higher if I wanted) with ease (but also a lot of oil, because it's still in progress!). I am about a quarter of the way through adding the second layer of insulation-- Originally that was going to be fiberglass, which some of it is, but I am also experimenting with recycling water bottles into insulation. I ended up angling towards using wood / vinyl flooring as my siding, because I had an excess, and it turned out to look kind of cool. This project is happening bit by bit out of pocket so it'll take some time.

The stove the original owner had was a Fisher that had been on our property that they cleaned up. There was a few issues with it. Someone had welded a badly made flue collar on top that was cracking. I replaced that with a new flue collar. After at least 2 years of research, I last month cut into my roof and installed the stove pipe. Thank god it turned out awesome and the woodstove works great with proper draw and can heat the yurt up fast. I'm going to post about that somewhere else.

I do still use a de-humidifier, especially in the summer.

I ended up having two installed windows and in the summer will have both my doors open with screens over them.

I am going to install a vent system specifically for shop stuff, mainly welding.

If you are thinking about using rigid foam insulation, I think it works. Remember that it needs to be continuous. Again, Fairbanks climate is fairly dry. I connected the foam boards together where they met with spray foam, and did spray foam at the bottoms of them, but did not seal the top part of the foam boards, based on the advice of this thread, so that the air behind them could vent upwards. That seems to really be the ticket.

Rigid foam board is really meant to go on the exterior of a structure. I think you might be able to attach 1" foam board under the awning of the roof. Most places want vapor barrier closer to outside, so for most places the rigid foam board being outside (with its foil siding as a vapor barrier) is ideal. For extreme cold climates (here) you want the vapor barrier closer to inside. I'm continuing to research how layers of vapor barrier interact. Always a learning experience.

@willothenorth
Thanks a lot for your update after those 2 years of experiment. I just finished setting up my 2nd hand 30ft yurt and living at 8,000ft in New Mexico, I also have rough winters... Single digit temp is rough enough with just "space" insulation )

Just would like some precisions from your earlier posts :
When you say that you framed the walls on the inside (adding support 2x4's to each rafter at the walls) and left a 1.5" gap behind... I'm not sure how you placed those additional 2x4 supports. Horizontal? How many in-between the 2 rafters? Maybe a schema or photo of your construction would really help 1st timers like myself. I have a bunch of wool insulation batts but adding rigid foam first like you did and then the wool and then plywood should solve my insulation issues for good.

Last, have you yet insulated the roof? Does leaving the roof as-is with your beefed up wall insulation is acceptable for now in your AK winter?

Many thanks again for your contributions!