My wife and I purchased her grandparents home in 2019. Last year we decided to start replacing the original windows from 1963! When removing the first window, we found that there was NO FRAMING in the walls at all. The wall consists of (starting from the exterior) 1/2 round cedar logs, approximately 6-8″ in diameter. Inside of that is almost a tar paper type material and then bubble wrap insulation. The interior wall is next as is 1 x 10 T/G. Both the exterior logs and the interior T/G run vertically. 

My first question is: Is this even safe? I realize that the exterior and interior walls handle the downward forces, but what is handling the sheer forces, both left to right and in and out? Buddies say: “It’s been holding up to all that mother nature can throw at it for the past 58 years, it should go plenty more”. Then I tell them to look at the old shed in the side yard (which is missing it’s roof and has a serious lean to it) and tell them that structure has also been standing up to the elements for the past 58 years. They typically change their tune on things.

Two of the windows we replaced last autumn were 9 ‘ (picture with casements on either side). On the non load bearing wall, all was good, but on the load bearing wall, there was a 1″ sag in the middle of the opening. We took enough of the T/G off to sneak in a rough sawn 1 x 12 as a header and placed it on top of some 2 x 4’s ripped down to 1″. Could not go to 2″ as there was no room!

Secondly, what would you all do if you were in this situation. We live in the UP, so winters are very cold. Summers can be hot from time to time, we have been in the 90’s the past 3 days. The lack of any kind of real insulation is a problem and we would love to replace the old cedar log exterior siding. I am not big for the Davy Crockett look!

Any and all advice would be welcomed!