Strapping down your roof for a hurricane - photo

[ranald]

I'm unable to comment on hurricanes but similar to Cyclones in southern hemisphere. Cyclones mostly give most damage to houses by the lifting motion or sucking up so homes built in Queensland since the eighties have had some cyclone rating structural work engineered according to the risk of exposure. The nearer the coast generally means a higher rating like many above 51 metres per second wind whereas further inland may only have a cyclone rating of 40 metres per second or less. As the rating goes higher, so does the size of the cyclone rods (long threaded rod that connects the footings to the roof structure) and other tie downs. Internal walls that brace against the possible wind direction also have rods or if in a lower cat rating may only have starter bars (or bolts). Its all about keeping the whole house tied together & secured to the earth. The size of roof battens increase, length of roofing screws, closeness of trusses etc. An "inspector" checking the house I was owner building in the late eighties exclaimed "you don't need to do that" refering to the sleel rods I was tieing from the footings to the reinforcing mesh of the slab. My response was "I know: but this is my own house". He nodded and walked off. The few dollars & time spent on unseen structural improvements were a "peace of mind" for me.

I have seen homes that have lost or broken a tile or two & emergency workers have done more damage climbing all over the roof to place a temperory tarp over the roof with similar tie downs or even much lighter ones.

During the 60's I was holidaying with my parents in northern Qld when a cyclone hit the coastal areas causing flooding hundreds of miles inland. It was like we were travelling in the eye and totalling missing all the carnage as we travelled north & then back south towards home. cars were thrown and washed off the highway, big gumtrees down everywhere,roads flooded, roofs blown away etc. What was particularly interesting was at Cannonvale (near Earlie Beach, Whitsundays ((Barrier Reaf delight)) the houses at low flats near the sea were mostly all destroyed whereas the really expensive (to construct) ones on top of the ridge (couple of hundred metres higher) immediately behind those destroyed were completely ok. The theory is that the wind up high hit the ridge and eddied down the almost vertical slope to doubly impact on the flats below. I would have thought, until I witnessed that, that the more exposed ones on top would have suffered more but "there you go".