Herman Aus

I was thinking of using something similar to a wall truss system to hold the insulation. That also makes attaching the wooden cladding easy.

Another option I'm considering is using thatch / reed in between the wall trusses. I have seen some old log walled barns here that have their exterior walls insulated with thatch. It's a great local resource but not the cheapest, which is why I'm thinking of other grassy alternatives.

There is a local company that even produces convenient, 5cm thick reed panels that can be used exactly like regular insulation panels but they are rather expensive.

Trying to find the best balance of natural, efficiency and affordability.

Another important consideration is the work involved with a particular method. Installing thatch costs more but would be quicker to install than clay straw and the overall insulation would be greater.

Thanks Andrew for the great resources. They have been a great help.

Foam insulation could work perfectly indeed - thin, warm and quick to install - but I'm too much of a purist to bring myself to using it.


Thank for the input everyone, appreciate the help.

Herman

Hey Andrew,

Very helpful study. Thanks for that.

Including the log wall and the exterior cladding, the maximum thickness of the wall I could allow is 35cm (14 inches). This would allow for a maximum of 15cm (6 inches) of straw clay.
The windows and the doors would be moved outwards accordingly but the roof overhand would have to remain constant.

Using the table from the study you provided and adding the R-value of the log wall, the total R-value would be about 18-20.
I think the recommended insulation here in Estonia is similar to that of Alaska - R-25 or so.

The lesser insulation value of straw clay is definitely a minus.
The affordability and local availability is a major plus though.

I appreciate your input Andrew, thanks.

Herman

Hello everybody! Happy to have found this forum - what a great online community!

I'm starting a building project, renovating an old house with 15cm thick, hand-hewn log walls. I'm thinking of bringing up the insulation value by adding insulation to the exterior wall.

As I was looking for something natural, affordable and DIY I found light straw clay insulation. My plan is to build a framework against the outer wall just as one would when insulating with regular batt insulation.
The exterior finish will be wooden cladding / siding with a small air gap 3-5cm between the straw clay.

I would love to hear other peoples opinion about this idea.

Thank you,

Herman