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Rain Screen

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Rain Screen

 

What does “Rain Screen” mean? 

 

In the simplest of terms, it is a wall built to protect a wall. It was an idea that was born out of necessity in the late 1980’s or early 90’s during the “Leaky Condo” era. Low rise condominium buildings were being built (mostly on the lower mainland) that were using exterior cladding that was not fully weather resistant. Some of the design features were also catering more to esthetics than weather proofing.  Just prior to this, the building code had been changed to call for improvements to insulation and specifically, vapour barriers. The advances in vapour barrier applications had made residential buildings so air tight, that they were now virtually “hermetically” sealed. This meant that there was no longer any heat (or air) escaping from the home, so any moisture that was getting past the cladding (siding) was left to rot the rest of the wall.

The remedy was a Rain Screen. Once the framed wall is complete with sheathing and a moisture barrier, spacers are applied over top and the cladding (fibre board, stucco, wood, vinyl or aluminium siding etc)  is then installed. This forms a gap between the structural part of the wall and the weather proof, cosmetic part. If any moisture somehow finds its way past the cladding, it drains down to an exit point and circulating air in that cavity allows any moisture to dry out. 

Though this procedure was adopted to remediate “leaky” condos and other residential buildings, it has become the norm for exterior wall treatments on most new builds. It is also the “fix” for any buildings that were built prior to changes in the building code to prevent premature deterioration of exterior surfaces. 

Most residential buildings now have Rain Screen walls, though a number of older condos have made it under the radar and are still nightmares waiting to happen.

It’s somewhat simple to detect if a building already has a Rain Screen system. To find out how, just send us an email or text.