After assessing the damage caused to buildings from Category 5 Hurricanes Irma and Maria, witnessing the heart-breaking misery of those who have lost so much, observing unrestrained looting of non-food items, and experiencing the halt to all national economic activity, I have returned to Barbados more convinced that we can avoid the foreseen national misery if we choose to.
The prevailing mind-set is that we cannot avoid such misery. It is expressed in terms like: “what will happen will happen”, and “if the roof is to go, then it will go”. This defeatist attitude that claims that homeowners can do nothing about foreseen threats explains the general absence of initiative to improve the resilience of our houses, which should be our primary shelters during natural hazards.
I bring good news. For despite the catastrophic building failures and the significant number of roofs damaged, there were many buildings that survived intact. These buildings had several common features that can result in economical building improvements for all Caribbean residents.
If your roof comprises metal cladding on a supporting timber frame, then your roof is likely vulnerable to extensive wind damage. Fortunately, you can simply strengthen your roof yourself, or you can get a carpenter to do it for you. I have calculated the following costs for the 3-bedroom 2-bathroom house with a hipped roof shape that is shown in the 1993 edition of the Barbados National Building Code, which I will conveniently refer to as the Building Code.
The wind will try to remove the metal cladding first, which should be 0.5 mm thick to reduce the likelihood of it tearing. The Building Code’s minimum standard is to secure the cladding with screws spaced 300 mm (1 ft) apart. However, past experiences with Category 3 and 4 hurricanes has resulted in screws that are spaced 150 mm (6”) apart at the eaves and ridges, and 300 mm (1 ft) apart elsewhere.
The roofs that survived Category 5 hurricanes exceeded this new standard by generally having one screw inserted between the existing screws. Therefore, the spacing was 75 mm (3”) at the eaves and ridges, and 150 mm (6”) elsewhere.
Approximately 720 additional screws are needed, and each screw cost about 35 cents resulting in a total building materials cost of approximately $250. A carpenter should be capable of installing the additional screws in less than one day for approximately $150.
If the cladding is secured to Plywood T1-11 boards, then the boards can be secured to the rafters with longer screws at the rafter locations. Each longer screw cost about 55 cents each.
With the roof cladding and boards secured to the rafters, the wind will try to separate the rafters. The rafters can be secured with BRC rafter connectors. Approximately 80 rafter connectors are required, which cost approximately $1.21 each, resulting a total materials cost of approximately $190 including screws. A carpenter should be capable of installing the connectors in less than one day for approximately $150.
The remaining roof connection is at the rafter and wall junctions. If truss anchors were not used, then this connection can be reinforced with rafter/purlin connectors. Approximately 120 connectors are required, which cost about 94 cents each, resulting in a total materials cost of approximately $230 including screws. In masonry walls, concrete screws can be used for an additional $90. A carpenter should be capable of installing the connectors in less than one day for approximately $150.
The total materials cost of securing your roof is then in the order of approximately $820. Homeowners do not need to do all of this work at once. They can start with the metal cladding and work their way down. Most of the work is simple enough that families can do it themselves. Of course there are other options.
The cost to replace the roof after the hurricane is approximately $40,000. If you cannot afford this, then you should either start saving or obtain insurance. If the house is insured, then the annual payments will be over $1,000 and you will be required to pay the initial $750 of any damage.
For both of these options, you would have lost your contents and will have to suffer through the misery of discomfort and reconstruction. Why choose this option when a better alternative of preventative strengthening exists?
A customer-focused home insurance company can consider allowing one annual premium to go towards roof strengthening. A caring Government can consider removing all taxes from hurricane connectors and screws, resulting in a price reduction of approximately 30%. The Minister of Finance has another opportunity to show that he cares.
The blogmaster invites you to join the discussion.