Protecting Homes Against Wind

Extreme winds, including tornadoes, are becoming a major concern for homes in Canada. Our country experiences the second-highest number of tornadoes globally. This puts houses at risk in one or more of the following failure modes:

• Roof uplift: Strong winds generate an uplift on the roof, tearing apart shingles, sheathing
• Window breaks: Flying debris penetrating unprotected windows 
• Structural damage: Extreme winds tearing apart structural elements from walls and roofs

… all of which can lead to: 

• Water damage after damage from strong winds leave the roof, walls or windows open

Homebuilders, developers, and renovators can help with more complex measures by:

• Installing window shutters to protect windows from airborne debris
• Using stronger bolts to anchor structure to foundation, keeping it firmly in place 
• Covering exterior walls with durable sheathing, including areas around windows and doors
• Securing wall panels with strong nails to improve resistance against wind pressure
• Attaching upper and lower wall panels for better strength and stability against wind forces
• Reinforcing gable-end walls by tying them back to the main structure
• Using sturdy materials for gable-end walls, like plywood or OSB
• Strengthening the roof-to-wall connection with special anchors or metal connectors
• Using more and stronger nails along sheathing edges to prevent panels from being lifted 

How do I know if severe wind is a concern for my area?

You can assess the severity of (normal) design wind conditions by consulting CHBA’s lookup tool for Appendix C of the NBC 2020.  In addition, you can find the likelihood of tornadoes for your area in the interactive tornado map (Northern Tornadoes Project - Event Dashboard). For potential future wind conditions based on projected global warming temperatures, values can be found in the design value explorer page for every location listed in the National Building Code’s Appendix C.

Where can I find additional resources?

Additional information can be found in the ICLR Severe Wind Handbook, ICLR Severe Wind Infographic. 

The most comprehensive set of construction and design guidelines to build tornado-resistant homes can be found in the CSA S520: High Wind Safety for Low-Rise Residential and Small – this standard is available for purchase in the CSA store. 

For more information, contact Bilal.El-Zaylaa@chba.ca