Insulating Floor and Ceiling of Log Kit House
I’m building a garden office from a log structure kit (rendering attached) and I’d really appreciate some advice on the best method to insulate the floor and ceiling. I’m based in Toronto and the building is only 108sqft, so no inspector will be coming by. I currently have a PT base on helical piles, with the bottom of the base around 8″ above soil. I’m hoping to use the building throughout the year, cooling with a fan in the summer and maybe a radiant/oil filled radiator during cold months. Electrical will be the only thing I’m brining into the building.
The walls of the building are 70mm thick pine and I will leave those uninsulated. I would like to insulate both floor and ceiling but I am not sure to what R value what would be appropriate as the walls will inevitably have such a low value.
I intend to throw rockwool (6″) between joists in the base, with a house wrap on exterior and vapour barrier under T&G floor boards. There will be an air gap on top of the insulation due the structure’s 2″ flooring strips that will be laid across the base joists.
For the roof I was planning on a warm roof assembly of T&G ceiling boards, vapour barrier, rockwool again (4″), ply, roofing membrane then final roofing material. But it looks like for this kind of construction I’ll also want to add a rigid foam between sheathing at top of assembly (?). I can go with just the rigid foam instead of the rockwool but I was looking to raise the R value.
Is raising the R value a moot concern as the walls will reduce the efficiency of the walls and ceiling?
Do these assemblies seem ok for this kind of structure (that I will spend at most 8 hours in, 4 days a week)?
Here is the link the structure
Thanks in advance!
GBA Detail Library
A collection of one thousand construction details organized by climate and house part