Published On: Thu, Oct 19th, 2017

Dutch experts in Trouw: “Making a house hurricane proof does not have to be that costly”

Hurrican Irma Relief Efforts 3

GREAT BAY – Reconstruction efforts must result in a better and stronger St. Maarten. That is the message from the local government and few will have an argument with that point of departure. But how this must be achieved is anybody’s guess. For the time being there is no information whatsoever to indicate in which direction the reconstruction of St. Maarten will go.

The Dutch daily Trouw asked four experts with expertise in designing buildings and knowledge of high wind speeds for suggestions and their opinions are somewhat comforting: solutions are simple and not very costly – at best a few hundred dollars per home.

Bert Blocken, a professor at the Technical University Eindhoven explained what happens when winds exceed speeds of 180 kilometers per hour – the situation of a category 3 hurricane. “The horizontal pressure on the walls and the roof becomes enormous and the house will be pushed sideward. Chances are that the roof breaks off and that it is lifted up in one go. Once this has happened the power of the hurricane wind enters the complete interior and stays there until the whole house has been blown apart.”

It happens even more often, Blocken says, that the roof and the walls are strong enough but that one door or one window collapses. “Once you have lost a window the whole house is often lost. The power of the hurricane then enters through that single hole and pushes the roof from underneath from the building.”

This is the reason why you see so many complete roofs on the streets after a hurricane says Vera Kreuwels, who recently visited St. Maarten for the Red Cross to document the emergency and the possibilities for reconstruction.

The solution is simple and not very costly, Kreuwels says. “Make sure, in whatever way, that the roof is properly attached to the walls and that the walls have a solid connection with the foundation. This way all parts keep each other together.”

Location is also an issue. Kreuwels: “In St. Maarten the poorest neighborhoods are built against steep hills that are catching most of the wind; these places are also vulnerable to mud- and landslides.”

“Don’t go and live too close to the coast,” adds Blocken. “A hurricane lands, as we express it. It touches the coast and often diminishes in strength on land. It is better to live inland than on the beach.”

Rob Nijsse, a professor at the Technical University Delft, agrees with these observations but notes that St. Maarten is an existing community and that it is not possible to start over from scratch. “People want to rebuild on their own plot as soon as possible. Of course they have to take the future into account, but they have to arrange their shelter right now. Therefore they will make provisionary repairs with limited resources and it is already clear now: that will never become a Siemens washing machine.”

Kreuwels says that the Red Cross is about to launch an information campaign that offers options for safe reconstruction. Among the suggestions is attaching the roof to the walls with steel wire or to use rebar that is used in reinforced concrete. There are also preformed storm anchors that cause the roof and the walls of a building to embrace each other. The last option is the most expensive.

The Red Cross will begin with the distribution of vouchers to the poorest citizens for the purchase of building materials. The vouchers have different monetary values and can be issued in series. “This way we can stimulate people to take simple measures to prevent future damages,” Kreuwel says. “Only when there is a storm anchor between the roof and the walls people will get the next voucher.”

According to Blocken making a home hurricane proof does not have to cost the earth. “A few hundred dollars make the difference between a sturdy residence and a blown away home. The thing is: you must have those dollars.”

devastation 20170916 - HH

Photo caption: A few hundred dollars could make the difference between a sturdy residence and a blown away home. Photo Hilbert Haar.