Interior sheathing / Guides

Interior sheathing as air & vapor barriers in wood frame construction
Air and vapour barriers

Interior sheathing as an air and vapour or vapor barrier

...interiors, the vapour drive reverses and can force moist air inwards through your insulation where it can condense on a cold and impermeable vapour barrier. Ideally we'd have no vapour barrier in summer; but short of that we should at least have one that allows as much drying to the interior as possible without sacri...

Choosing between OSB or Plywood for house sheathing for Roofs, Walls & Floors.
Wood and organic materials

Which is better, OSB or Plywood for Roofs, Walls & Floors?

...sheathing, and those panels are designed with it on the interior . Placing insulation on the outside would keep the sheathing warmer, and reduce the risk of condensation forming. Placing it on the inside of sheathing could have unanticipated and undesired results. And this from the Canada Mortgage and Housing Corpora...

Passive House wall system ; Larsen Trusses & dense-packed cellulose insulation
Wall assemblies - new construction

Larsen truss wall systems with double-stud construction & extra insulation for new homes & energy efficient home renovation

...sheathing, then I-joists (TGIs) attached to the exterior of the sheathing to allow for seamless insulation with no thermal bridging . The sheathing is used as the air barrier and vapor barrier , by using a high-performance building tape to seal the joints and the Larsen Trusses are effectively a cost-effective and ligh...

Building science for LEED v4 wall design made easy
Concept and design

Building science for LEED v4 wall design made easy - video

...sheathing; the difference is that vapour and air control layers are moved to the exterior of the sheathing, then additional insulation is installed outside of that. Stud cavities are still insulated with batts, but the majority of insulation is on the outside of the sheathing, this way the vapour control layer is san...

Installing Siding Correctly
Exterior cladding

How to install siding

...sheathing and cladding is an important part of the strategy needed to allow walls to shed moisture in all seasons and conditions. Drainage planes (building paper, house wrap, etc.) allow any moisture that does accumulate behind siding a chance to drain away harmlessly. The air space between siding and sheathing shoul...

Off grid, passively heated and cooled house in the Gatineau Hills, Que
Off-grid and Net-Zero Housing

Off grid living blog, part 2: passively heated, this house in Quebec aims for LEED certification

...sheathing; house wrap; strapping; cement board siding. The ceiling is a mix of Roxul mineral wool batts and cellulose totalling R80, the basement is a mix of EPS foam and Roxul batts totalling R28. The benefits of a double exterior wall are plenty. It eliminates thermal bridging through studs, provides lots...

How to Build With Less Wood for Best Performance
Wood and organic materials

How to build high performance homes with less lumber

...sheathing, which is OSB with either 1 or 1.5 inches of EPS foam attached . This was something of an easy ad-on to meet the thermal requirements using a bit of foam, but there are durability concerns. Exterior sheathing insulated with foam can trap moisture in walls. Foam is at least a vapor ‘retarder’ (which sl...

The difference between air barriers and vapour barriers
Air and vapour barriers

The Difference between air barriers and vapor barriers

...interior with at least 2/3rds of your insulation on the outside of the vapour barrier. Air barriers on the other hand can come in the form of house wrap (WRBs) , tightly sealed sheathing, insulation that slows airflow, and well-sealed gypsum board (drywall). To explain this further, Gypsum board (drywall) is vapor pe...

Choosing a building envelope
Wall assemblies - new construction

Choosing a building envelope - starting with the perfect wall

...sheathing, then I-joists (TGIs) attached to the exterior of the sheathing to allow for seamless insulation with no thermal bridging . The sheathing is used as the air barrier and vapor barrier , by using a high-performance building tape to seal the joints and the Larsen Trusses are effectively a cost-effective and ligh...

Tyvek home wrap left exposed to wind and UV rays
Air and vapour barriers

Choosing the right house wrap / weather barrier, which is best?

...sheathing will impact vapour permeability of the wall assembly as well. [Read more about material permeability here] . Conclusions about the vapour permeability of sheathing seem to differ heavily from different sources, We will run with the pack on this one for now, using the numbers most manufacturers cite. 7/16"...

Passively-heated off-grid LEED house in Low, Quebec
Off-grid and Net-Zero Housing

Off-grid living blog: a firsthand account of building and living in a remote area

...sheathing. Beneath the sheathing are manufactured trusses with 3' of depth built in for insulation. Into this space a layer of 3.5" Roxul batt insulation was laid down covering the entire bottom of the ceiling cavity. Loose cellulose insulation was then blown in above, mostly filling the 3' space, reaching an estimat...