A number of engineers and builders have told The Myanmar Times future construction projects should protect against cyclone conditions.

IN the disastrous wake of Cyclone Nargis, construction experts in Yangon say new buildings should be designed and built to withstand cyclonic conditions.

These conditions include 100-mile-an-hour winds (160 kph) that make buildings sway on their foundations.

U Saw Htwe Zaw, a structural engineer, said most buildings in Yangon were built to handle winds up to 80 miles an hour (128km) because conditions worse than that had not emerged before.

“In the past, wind speed was not a major factor when building in Yangon. But since Nargis, wind resistance has become crucial, and design loading [maximum tolerance] should be increased to 120 miles (192km) an hour. This is especially true for roofs, windows, aluminium cladding and panels,” he said.

However, U Saw Htwe Zaw suggested that all new buildings, including private houses, apartment blocks and community buildings should incorporate stronger foundations and frames, even though it will increase the cost.

Part of this plan, he said, is using better – and more expensive – building materials, which have a direct effect on the building’s overall strength.

“Ready-made concrete offers better quality control compared with manual mixing but is more expensive. And when it comes to steel rods there is the same situation: Better steel costs more but will last longer with less chance of failure.

There’s also a market shortage for the higher-grade steel at the moment.

“But if you don’t use the higher-quality rods there’s a chance that the overall strength of the building will be undermined,” he said, adding that better rods will raise costs by about 20 percent.

Increasing the overall strength of the building would also prevent swaying, especially in stand-alone high-rise apartments, he said.

“Swaying during a storm or high winds will be more noticeable in open compounds than downtown because there is a collective strength and buildings support each other. But for apartments standing alone, any movement in the lower levels will be amplified in the higher floors: movement of one inch [2.5 centimetres] in the basement will be 3 inches [7.5cm] on the seventh floor and 9 inches [22.5cm] on floor 20,” U Saw Htwe Zaw said.

Architect U Than Tin Aung agreed that new buildings should be constructed with Cyclone Nargis in mind, but included other potential natural disasters as well.

“New buildings should be constructed with earthquakes in mind too.

“Structural loading levels should be increased for columns, external walls and supporting aluminium glass walls and roofs because these are the most likely areas to come under heavy pressure,” he said.

He added that tests were critical in determining poor soil that could undermine foundations and permit undue building sway.