*
I am currently designing a house and would like to add some 1″ or 1 1/2″ extruded rigid insulation to the outside framing of the exterior wall for some additional insulation value.(I live in Canada, and yes it’s damned cold here) However I would like to place it directly over the studs (to reduce thermal bridging) then apply the Plywood or SOB sheathing over the insulation. The Exterior wall construction is as follows:
Exterior Wall Construction:
Fiber Cement Cladding,(James Hardier)
Air Barrier,
1/2″ SOB Wall Sheathing,
1″ to 1 1/2″ Extruded Polystyrene Rigid Insulation,
2×6 Studs @ 16″ o..,to 2′-0″ o..,
R20 to R23 Glass Fibre Bat Insulation,
Vapor Barrier,
1×4 Horz.Wood Strapping,
1×4 Vert. Wood Strapping
Gypsum Board
Have you ever heard of this being done? and if so do you have any information, details, and or suggestions.
My concerns would be the length and deflection of the fasteners from the sheathing to the wall studs ( ie. 1″ to 1 1/2″ )obviously these would have to be increased in length and gauge and be accepted by the governing building codes.
Given that we platform frame, the exterior framed walls are squared and plywood sheathed and then are raised into position, as opposed to the sheathing being applied after the walls are raised. Obviously the walls would have to be squared prior to the application of the rigid insulation against the studs, and then sheathed.
Insulation applied horizontally? (perpendicular to wall studs or does it matter?)
Would mechanical fasteners be sufficient for the insulation or would a compatible construction adhesive also be used in conjunction with the
fasteners?
Replies
*
yes, we used to do that.. (exterior).. it was too complicated..
now (if we want an energy wall) we do EPS inside.. furr the inside.. and blow the cavity with cellulose..
*Is James Hardier the Quebec version of what we down here call James Hardy?
*Yes, but in Chicago we spell it Hardie.ERIC
*Eric. M. BorgmanWe call it James Hardie up here Alberta also, unfortunately spell check sees it as "Hardier". My personal favourite however, is SOB in stead of OSB.How did you secure the plywood over the rigid insulation? (Given 1/2" OSB or plywood sheathing over 1" to 1 1/2" extruded polystyrene insulation, on to 2x6 wood stud framing @ 2'-0" o.c.)Size and Length of fastener (shear concerns)?Did you run into any problems with your building code?Do you have any sort of documentation testing or acceptable building code table or wood council regarding this type of assembly?A different assembly other than the one I am describing is as follows which utilises a rigid fibre board and or insulation in lieu of the plywood or OSB sheathing. Owens Corning have a board which is manufactured with an integral air-barrier membrane, after installed all the joints are taped. You get around the shear by providing let in diagonal bracing in addition to your interior gypsum board finish.Would appreciate a description of how you did it.Thanks in advance
*Mike was looking over the picture you sent (thanks for the reply),but I don't see any vapour barrier in the photo unless your going to apply it to the face of the strapping, prior to securing your interior drywall, is this so?I know some building codes go so far as to say that you do not require one by using a specified paint on the interior surface of the drywall but it won't work up here.
*the 1 inch eps is a vapor barrier..but also i've adopted a lot of the air sealing techniques some of these guys are using...and since i'm using cellulose and air sealing i don't use a seperate poly vapor barrier...if this had been insulated with fiberglass (friction fit ) there would have been a 6 mil poly vapor barrier...but ... eps or just blueboard with skim coat plaster, we blow cellulose...
*
I am currently designing a house and would like to add some 1" or 1 1/2" extruded rigid insulation to the outside framing of the exterior wall for some additional insulation value.(I live in Canada, and yes it's damned cold here) However I would like to place it directly over the studs (to reduce thermal bridging) then apply the Plywood or SOB sheathing over the insulation. The Exterior wall construction is as follows:
Exterior Wall Construction:
Fiber Cement Cladding,(James Hardier)
Air Barrier,
1/2" SOB Wall Sheathing,
1" to 1 1/2" Extruded Polystyrene Rigid Insulation,
2x6 Studs @ 16" o..,to 2'-0" o..,
R20 to R23 Glass Fibre Bat Insulation,
Vapor Barrier,
1x4 Horz.Wood Strapping,
1x4 Vert. Wood Strapping
Gypsum Board
Have you ever heard of this being done? and if so do you have any information, details, and or suggestions.
My concerns would be the length and deflection of the fasteners from the sheathing to the wall studs ( ie. 1" to 1 1/2" )obviously these would have to be increased in length and gauge and be accepted by the governing building codes.
Given that we platform frame, the exterior framed walls are squared and plywood sheathed and then are raised into position, as opposed to the sheathing being applied after the walls are raised. Obviously the walls would have to be squared prior to the application of the rigid insulation against the studs, and then sheathed.
Insulation applied horizontally? (perpendicular to wall studs or does it matter?)
Would mechanical fasteners be sufficient for the insulation or would a compatible construction adhesive also be used in conjunction with the
fasteners?