for Cold Climate Housing and much more

Last Updated: , Created: Thursday, October 14th, 1999


Yes, but maybe not good enough.

Sheathing paper is designed to keep outside water and wind out of the walls but to let inside vapour breath out (like your skin does for your body). Over the years, manufacturers have made the traditional sheathing or building paper stronger, but at the same time less permeable. That means it lets water vapour through less easily, sometimes adding to condensation problems.

As we increase the amount of insulation in the walls it becomes more and more important that the walls breath easily and dry out quickly when accumulated frost has a chance to melt. Today's 15lb felt paper may no longer be doing as good a job as it used to in houses that had warmer walls.

A whole new series of sheathing papers, or "house wraps" are on the market now. Their main advantage is that they stop water just like the old sheathing paper, they are even more permeable than the old paper meaning that they breath better and especially that they come is wide enough rolls to literally wrap the house with very few joints. Few joints means no wind penetration. Properly taped at all the joints and edges, these house wraps become Air Barriers, something that the old sheathing paper could never accomplish. It all started with Tyvek and now there are many choices, and qualities on the market.

Although these appear to be plastic sheets, they definitely are not vapour barriers. The Tyvek is made permeable because it is actually made of woven plastic fibers. Others have pin holes in them to accomplish the same thing. There are now many on the market with different price ranges and different characteristics. You can use these house wraps in a lot of other places where a non-vapour barrier sheet would be useful. You use it in place of chicken wire to hole insulation up under floor boards; it provides strong support and a complete air barrier, but no vapour barrier. You can lay it over the top of loose-fill insulation in the attic to keep it from blowing around, thereby providing an air barrier but not stopping vapour escape.

For those who want to leave off the sheathing paper all together, search keyword "house wrap" for the title "WITH EXTERIOR INSULATION -- DO I USE BUILDING PAPER? DO I CAULK THE JOINTS?"


Keywords: Walls, Siding, House Wrap, Sheathing, Ventilation

Article 746