What Type of Roof Is Best For Hot Climates?
There is a running joke about the two seasons that we have in the Philippines: hot and hotter. With rising temperatures and overall global warming, we have to make the best out of our tropical climate and not fight it.
It may come as a surprise that artificial air-conditioning isn’t the only way to cool our spaces. If you are currently building or planning to build a house, choosing the right type of roof design and material may be crucial to the coolness of your home, all-year-round.
Architect Joel Muñoz, who specializes in tropical design, reveals that our ancestors—with their traditional bahay kubo or thatched huts—were right from the get-go in creating roofs that naturally helped cool their living spaces. “Our traditional vernacular architecture shows very steeply-pitched, tall, organic roofs,” Joel explains.
Here, he shares with us the best type of roofing materials and construction for a cooler home.
Have a proper roof pitch
“A good roof pitch would be atleast 30 degrees, although traditional vernacular samples may go as high as 45 degrees, which I think is better. There are examples of bahay kubo with the house-to-roof ratio of one-is-to-three—meaning the height of the walls of the house is one-third the height of the roof—which makes for very cool interiors since the inhabitants are very far from the hottest part of the house as well as all the rising hot air. Since materials then were organic and porous, the rising hot air escapes quite easily, making the cooling cycle very effective.”
As much as possible, avoid creating an attic
“The roof is the hottest part of the house, therefore it is not a good idea to have attic-rooms as bedrooms or living spaces in tropical hot/humid climates. These work best for western architectural styles and climates.”
Use natural materials
“I still believe natural/organic materials are the best choice as roofing for tropical houses, except for their rapid deterioration. Conditions long ago allowed for such flimsy materials such as grass, thatch, reeds, etc. The environment then was cleaner, unpolluted, and less harsh. These materials breathed easily, cost less to maintain, and were visually pleasant. Although in better, less polluted climes here in our country, I have seen houses still thatched with nipa and cogon that have lasted years, possibly as long if not longer than the conventional galvanized iron roof.”
Or use clay roofing
“For the city, a clay tile roof or a cement tile roof might be best. It's the least thermally conductive [material] and it lasts longer. It is also sturdier during typhoons because of its weight.”
If using a GI roof, make it white (or light)
“There are, however, studies that show that a galvanized iron roof (G.I.) would work as well since it heats up quickly and cools down quickly once the sun disappears. The trick is how the stored heat inside the roof is released just as quickly, so roof vents would be a good solution. [For paint,] light and reflective colors are best.”
Try a “green” roof
“You may consider having a ‘turf roof.’ This is a somewhat new concept for our country although it is gradually catching on. The technology is not entirely here yet, but alternatives can be used. This would literally and figuratively be a ‘green’ roof since it is planted with ground cover over soil and aggregate layers. It definitely lowers temperatures for the interiors. Leakage may be a problem though especially during the heavy rainy season so effective water-proofing and drainage is key in its design.” [For green roofing, check out the products at Sika Group—Ed.]
This article originally appeared in “25 Tips For The Tropical Home” in the April 2009 issue of Real Living magazine.
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