[woodzyff]

Hello,

I am looking at retrofitting my home by adding exterior insulation. I'm not sure on the best way to do this to avoid moisture issues. I live in North Western Ontario and our climate can get as cold as -40 degrees C and as warm as +35 degrees C and humid.

The house is of milled cedar log construction. The logs are roughly 4" x 7" and feature a double tongue and groove. The house was built in 1971 and insulated on the exterior not long after with 1" styrofoam and then cedar siding. I plan on removing the siding and the insulation and replacing with something better. The cross joints stick out 5" and "section" off the exterior of the house. I will add pictures shortly.

I'm thinking of a few different options:

- Framing a false wall with a space behind similar to an insulated basement wall to allow 1" spray foam behind. Then insulate the cavity with bat or cellulose insulation.

- Building a false frame wall (larsen truss possibly) and using a sealer paint on the logs as a vapour barrier and then blow in insulation in the cavity. Could also use a poly on the logs but it will be hard to seal.

I've been scratching my head on this for a while... any advice or opinions would be great help.

Thx

 

[Windows on Wash]

So you have 1" foam and you want to remove it and the siding as part of the retrofit?

Is there anything wrong with the siding? What type of attic does the home utilize? What are the levels up there?

How about some pictures? This seems like a significant undertaking if the siding in good shape and not warranting replacement or service.

 

[Bud9051]

I wasn't sure what to suggest here, but WOW's suggestion to consider other possibilities is a good one, and this could be a really good home to have an energy audit done with infrared pictures. Being in Canada you should have access to some help with the energy audit.

But, what you will get is an indication as to the savings for various improvements. I assume you are thinking about the new wall insulation because you have either an energy cost issue or a comfort issue, or both. An energy audit (I do them) will target your efforts and investment. I've seen too many major projects result in minimal improvement.

Bud

 

[Gary in WA]

I framed a couple of houses as described- in "70's. The spleen was a plywood/wood piece fit in between the logs, 8' tall. The logs do expand/contract over the seasons and with age; hence the height-adjustable spline to tighten the chine gaps with only the rubber weather-stripping gasket to keep out air, no mortar/clay. Exposed rafters with insulation/sheathing above, no attic with possible loft for sleeping. Since you obviously want to keep the appearance on the inside, insulation should be exterior.

Poly inside would be required per location, or exterior foam thick enough to warm the dew-point of sheathing against condensation. Normally. Describe the chinking material, is it air-tight to act as your air/vapor barrier? As said, pics would help...

Gary