question for insulating 1800’s log home
Hi,
I’m working on our 1800’s log home in Pennsylvania. Original home is 22 X 24. Just finished a 12 X 14 ft. two floor addition off the east side. The outside of the house was originally covered with vertical board and batten. At some point the battens were removed and they covered the board siding with the asphalt sheets with the brick pattern. Inside of the addition I exposed what was originally the outside wall logs of the house. They seem in good shape and I like the look. As I move inside and start working on the renovations I’d like to expose the logs in some of the walls. The interior side of all the outside log walls are covered in lathe and plaster and are in fair shape. My quandary is how to add some insulation to the walls especially if I’m exposing some of the log walls inside? I plan to apply fresh board and batten as exterior siding, returning it to its original look. A suggestion that I received and used on the southern exterior wall is to nail 1 X 3” horizontal nailers right over the “bricks” every 2 feet, applying 1” blue board between the nailers and going overtop of that with the vertical 1 x 10 inch rough sawn pine boards and battens. I will re-chink the logs on the inside but I’m thinking w/o the plaster there will be even more moisture going through the wall in the winter. So, how can I add some insulation w/o creating a moisture problem in the wall?
(home has a new metal roof with Icylene open cell foam at roof and on gable ends in attic. Addition has same insulation in walls and at roof.)
Thanks for any wisdom you can share.
Replies
What kind of floor do you have? I'm thinking about water vapor coming up from the ground.
You should do more than one inch of foam if that is your only insulation layer. I would think about filling the low areas with densly packed insulation, plus at least 2" of foam board on the outside. I would cover the foam board with an air barrier then fur it out with horizontal nailers... then apply the new board & batten.
Basement does have a cement floor and it stays pretty dry. Wood floors everywhere else. Oil furnace/hot water. I plan to add a wood stove in living area down the road.
Help me think through the moisture issue going from the inside out? I don't want to trap moisture anywhere. I guess that was why I was thinking not getting it too tight. Or does adding more insulation and an air barrier outside help with moisture staying in the wall? What about that outside asphalt paper on there now. Is leaving that in place and going overtop a good idea?
Thanks!
I think you should be OK then, it doesn't sound like you have a dirt crawl which would require some serious sealing first!