In Vancouver we often experience rain and this is not always the ideal weather for any exterior work.  One of our clients recently asked me, as the construction of her garage was in progress, how the building paper will be affected when you leave it exposed to rain for numerous days.  We couldn’t shingle because rain makes Hardi-shingles soft and they break.  So in the meantime, what will happen to the building paper after long periods of exposure to less than ideal weather?

Building paper is made from Kraft paper (produced from wood pulp and very strong & coarse) which has been saturated with waterproofing asphalt, the same product used in asphalt pavement to bind aggregate together.  It is very resistant to wet environments.  The purpose of building paper is initially to prevent wind from penetrating into a wall and secondly to act as a backup moisture barrier behind cladding.  In wet regions, the second function is very important since moisture in a wall is definitely not desirable.

For any climate, two layers are recommended.  The outer layer of paper can become damp from wet cladding so having two layers means that the inner layer keeps the wood wall separated from direct contact with this dampness.  The outer layer can take the abuse of numerous wet and dry cycles in the wall while the inner layer remains unaffected over time.  Regardless, it is best to cover any moisture barrier as soon as practical since you expect it to perform for many decades.

The Schluter workshop was an invaluable experience.  It was run very professionally and included introdutions to many of their products as well as hands on experience installing.  The Schluter system is a well thought out system that is engineered to work without second guessing your product or the install.  The purpose of Schluter varies from tile installation, to waterproofing membrane, and even deck installs.

The use of Ditra, a flexible membrane, allows tile to be installed with unmodified thin-set.  The Ditra’s dovetail grooves lock the tile in place and the membrane allows for flex, which eliminates cracking if installed correctly.  This type of install eliminates many problems associated with exterior installation and commercial stress.  Kerdi, is a thinner membrane that is primarily used in shower applications.  It eliminates the old and more, challenges waterproofing method, which requires a much more skilled worker.

These two applications are just part of the Schluter system which was introduced to me at the workshop.  After the two days spent working with and around Schluter, designers, plumbing inspectors, tile setters and myself were all impressed.  Simply a great product that sells itself!

Garth Lagasse
Estimator / Project Manager