For the most part, many of our building exteriors are as a result of the materials we could find in our immediate surroundings.

Wood siding is traditionally laid horizontally in strips or planks. With the advent of building wraps or air barriers, wood siding now requires to be mounted away from the sheathing surface with vertical strapping, due to the escape of moisture from the stud wall cavity. Should strapping not be installed, water builds up behind the siding causing rot and mildew. The strapping creates a cavity where air can pass through and water can drop to the ground; this in essence is called a rain screen. 

Vinyl siding has its own built in rain screen and is applied directly to the air barrier and sheathing surface. Vinyl doesn’t hold the same charm as wood and I feel it is a colder alternative and yet cheaper. Not to appear snobbish but it is my preference, although vinyl does have its place and with the right detail, it can look appealing.

In Europe, houses are still made with brick, although in North America brick is used more as a veneer than a structural element. Clay bricks are laid on a bed of mortar and stacked in various patterns; the most common is the running bond where the brick above is centered over the perpendicular joint below. The brick wall is built approximately one to two inches away from the main structure, creating a rain screen. Clay bricks are porous and driving rain seeps through the brick forcing its way to the sheathing surface. Galvanized brick ties are spaced at intervals connecting the brick wall to the main structure. These ties are designed to prevent water gaping the cavity and channeling rain water down the cavity to the base where weep holes allow the water to escape.  Bricks is a durable material and tends to be maintenance free unless the clay made to make the brick has salt deposits in it. Efflorescent as it is known appears on the brick surface. One can remove this build up of salt, perhaps best not used on your fish and chips, by soapy water and brush applied with elbow grease.

Stucco

Stucco is durable and traditionally used in warmer climates and is made with a composition of plaster, lime, sand and water. Now we add Portland cement and acrylic along with other additives to strengthen the product. A stucco base coat is applied onto a mesh and then the finish coat. A rain screen is needed if applied to a wood framed structure and depending on the extent of stucco used, it is recommended to provide expansion joints every so often at intervals specified by the manufacturer to prevent cracking.