Building Envelope Detailing for the BC Coastal Climate

The coastal reality

The Lower Mainland and Fraser Valley get sustained wind-driven rain for months at a time. An envelope that would perform adequately in a dry climate will fail here if the transitions are not detailed and executed properly.

Where assemblies actually fail

Failures rarely occur in the middle of a wall. They occur at transitions: window and door perimeters, balcony and deck junctions, parapets, roof-to-wall interfaces, and every service penetration. These are the details worth the extra attention.

Drainage and the rainscreen principle

Assume water will get behind the cladding, then give it a drained and ventilated path back out. A properly executed rainscreen cavity with continuous flashing at each termination is far more reliable than trying to build a perfectly sealed face.

Continuity of the air barrier

An air barrier only performs if it is continuous. It has to be tied into window frames, roof membranes and foundation, with compatible materials and sealants at every joint. Discontinuities are where both air leakage and condensation problems begin.

Getting it right on site

Good drawings still need correct execution in sequence and in weather. Our crews install EIFS and exterior assemblies with the transitions detailed as specified — and we flag conflicts before they are buried behind cladding.