Posted April 27, 2017 11:20:30

Photo: Most heritage and even many newer buildings in Tasmania were not built to withstand strong winds.

Tasmania's heritage buildings are taking a battering from gusty winds they were not designed to withstand.

Engineer Peter Spratt specialises in repairs to heritage buildings and said he responded to 55 buildings with wind damage in the past 12 months.

"When we run a computer analysis of the roof structures we find that invariably they're capable only of resisting winds of 60kph," he told Helen Shield on ABC Radio Hobart.

"We have had winds in excess of 100kph some 30 times in Hobart in the past 18 months."

Photo: Even relatively new buildings in Tasmania are often not built to withstand heavy winds. (ABC Northern Tasmania: Fred Hooper)

Historically little attention paid to roof construction

Mr Spratt said it was not just older sandstone colonial buildings that had problems when wind gusts get too strong.

"New buildings that are more than 10 years old often have cracks and they have cracks from wind damage," he said.

"It's only in the past 10 years that there's been attention paid to the roof construction and tie-downs and wind loads."

Mr Spratt said the only way to prevent heritage buildings from needing extensive repairs in the future was to make changes to their roofing now.

"We have no option other than to stiffen the roofs to be able to resist the [current] Australian standard of 150kph.

"It is a big ask, but if you don't to it you may get damage that is not repairable."

Is Tasmania getting windier?

Bureau of Meteorology climatologist Ian Barnes-Keoghan said detailed recordings of wind speeds in Tasmania only dated back to the 1940s, and until the 1990s only a handful of sites monitored wind speed at all.

In July 2016 wind gusts of more than 100kph were recorded on four days at the bureau's Battery Point observation point, which is a record for gusty days in July.

Mr Barnes-Keoghan said it was hard to determine any trends with wind speeds as gusts were often highly localised events and recordings did not go back all that far.

Projections for the climate into the rest of the century suggest a modest increase in windiness during winter in Tasmania, but perhaps a slight decrease during other times of the year.

Topics: history, architecture, weather, human-interest, hobart-7000