Fenestration Review

Technology Adhesives & Sealants Glass Technology
“Rainscreen Window/Wall Interface” research project has begun


January 30, 2020
By Jon Eakes

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In 2011, NRC research concluded that trying to stop the wind and the rain at the same place does not assure long term durability of water control in residential window installations – exactly what we do when we caulk, tape and foam the window at the level of the mounting flanges. For the last year and a half, discussions at window conferences across Canada has led to research projects at George Brown College in Ontario and Red River College in Manitoba being designed to define and quantity the role drainage paths and pressure equalization can play in providing more reliable, and probably less expensive, residential window installations in new cold climate construction. I am calling this the “Rainscreen Window/Wall Interface”.

A small preliminary project at George Brown College, supervised by Dr. Chris Timusk, is focusing specifically on what pressure equalization between the drainage plane and the forces of the wind can contribute to the control of moisture ingress in residential window installations.  This project is considered as a first step in preparing the larger Red River College project.  This project is presently in the process of building the test wall.  The project is moving forward because of College scheduling restrictions despite the fact that I have not succeeded in securing all the basic funding planned for.  Presently we are $1,500 short of our initial budget, and another $2,000 short of our dreamed for budget. If any Ontario based (a requirement of the research matching funding agency) window manufacturers, or window installing companies would like to support this effort, please contact the administrator of the project, Arbab Khan, (416) 415-5000 ext 3508 – Arbab.Khan@georgebrown.ca.

The project at the BETAC division of the Red River College in Winnipeg has recently had its first advisory committee meeting after securing its funding.  It is presently projected to be a one year project.  They are going to undertake some initial THERM modeling, especially on the thermal contribution of the dead air space in a drainage plane – part of evaluating a payoff balance between insulation and drainage in a limited space.  The George Brown College project should have wrapped up before plans are finalized for lab testing at BETAC so whatever is learned at George Brown will be used at BETAC.  If you would like to contribute in some way to the Winnipeg project, contact Rob Spewak, Technology Centre Manager, (204) 632 2357 – rspewak@rrc.ca .

I will be keeping everyone up-to date on all developments.

In my next newsletter I will be presenting various innovative products that we have come across during our cross Canada discussions relating to residential window installations simply to make you aware of what is developing in a rapidly evolving field.