Francis Lepage

thank you for the information, very appreciated. so many options ill figure it out when time comes.

thanks for taking the time to reply guys!

the one thing i dont understand is how can this (shallow foundation type of insulation) prevent that freezing cold rock from sucking all the heat of the floor? If you were to build a concrete slab i am pretty sure the slab would be extra cold unless you built in a warming system or unless you use this 'aircrete' mentioned above. But still you would have to constantly fight against the cold and have to put in a hughe amount of energy.

The thing is i am not interested into concrete slabs for the moment...I am thinking about a wood planks floor with an airspace beneath. So i am guessing the air beneath is going to be extra cold from the cold rock even with side insulation...is it not?

i know i am in passive solar forum and i am talking about a non-massive floor :S my appologies. But still even with concrete it is still a concern...

hey all!

i have a question... i tried to answer it on internet but could not find the information :/

i am wondering what is the best way to insulate the ground below a structure (house or greenhouse) if you hit bedrock before frostline? because i am guessing insulating perimeter walls only wont do it... so what options there is? do you need to insulate flat on top of the rock? or maybe a combination of perimeter walls and skirt? Let me know please!

hi Devin, like you i am trying to look into ways to insulate the floor organically and i cannot find much information on the web... One thing i ask myself is do you really need to insulate a floor? Because if warm air rises i wouldnt see how it would leave the house from underneath...I thinking, at least preventing winds from going through the floor by chinking floor boards (for a wooden floor) and also by chinking/closing foundations.

I have read about wool and i think it is a very good idea. I wonder if someone have experience with it and could give more details. I gues you would just have to lay it between floor and subfloor. And also, i remember watching a video of a log cabin construction where floor was being insulated with sawdust. But from looking on the internets i have only found negatives opinions on sawdust...And i wonder if there would be a higher risk of fire?

I know from where im from the old houses use to be insulated in their floors with a layer of news papers (a proper use for that crap) and rags. I just dont think the insulation value of it is very high.

I forgot your question was about underground construction... I had above ground building in mind. Maybe underground you take advantage of the more constant temperatures of the ground so in fact you dont need to insulate from it?

So on my land i have heaappsss of trees. Thats the main reason im building a log house. I prefer to use local material when possible. Ive been changing and changing the design quite a few times but now i think im finaly happy with it. The house is gonna be pretty much square with a lean-to turf roof. The "opening" of the lean-to facing south with lots of windows and a greenhouse in front. And like i told you i will add different rooms all around. The north side is going to be just a little inside the forest edge to protect me from the constant north winds.I have considered the wofati, i really like the idea, but for in case i think i would prefer to stay out of the ground so the house can be dryed by the wind because it is so wet here...

Do you have any ressource on the land where you are that you could use? The fact that you are on south facing slope is amazing. Use that to your advantage. If you are limited in logs you could build something integrated in the ground. An easy way could be just digging into the slope a few meters and use that dirt wall that you would have just created as your north wall. You just would have to manage water properly somehow...probably wofati could tell you more about that. So that could be a good way to use less wood. You would basicaly just need to build a south wall with lots of windows (so even less wood) and a roof. Maybe some part of east and west walls too. That would look nice!

There is also cordwood... I dont know if it uses less wood than a log house? I would say probably because you use lots of mortar... Thats a very cool and warm way to build a house but you woild have to dry the logs first.

And another thing i thought about if you are interested is a Yurt. That could be cheap if you build the frame yourself with the logs you already have. You only would have to buy the tarps or whatever its called.

Anyway just sharing some ideas to help you out. The more you have the better!

Hi Zach,
I understand you it is hard to find positive feedback sometimes where i am too. Where abouts in Canada are you? I am from Qc maybe i can help you?

In my opinion to isolate a log cabin you need to build around the living place. What i mean is find out where do you think you are gonna spend most of your time when you are inside (kitchen,bedroom, fireplace,etc) and then use this room as the central point of the house and build around it. You could attached a workshop on the east wall, a greenhouse on the south, bathroom west side, shed/wood storage on the north... These are only examples to give you an idea. That way the main room that you are going to live in and heat as well is not going to be next to outdoor temparature. The added rooms add temperature transitions area. If i translate it from french it is called Shell insulation. That is what i should start doing pretty soon. Although, i am going to build my log cabin with a different shape to maximise sun gain.

I understand you might have a limited supply of logs so maybe what i am proposing requires a bit too much logs...Maybe you could build the core out of whole logs and then after build around with a different technique?