Costa Rica Construction – Avoiding roofing problems during the rainy season

During the rainy season here in Costa Rica the grass and plants get their greenest and moisture saturates everything it comes into contact with. We see more green mold develop on horizontal concrete surfaces and if not cleaned regularly, it can get slippery.

You may also notice a kind of shadow on vertical surfaces of buildings where the rainwater flowing down off the roof has brought dirt along with it. A consistent maintenance plan can help prevent these inconveniences.

If your exterior roofing has held up during this year’s high precipitation, then you’ve got a good installation. I’ve been here constructing housing since 1992 and have seen roofing installations fail after the first rain and others that kept a dwelling dry for several years and then began to leak with no obvious problems visible.

The reasons vary, but the lack of consistent cleaning and maintenance practices on homes and buildings are responsible for a good portion of the problems.

Costa Rica Roofing – Facts you should know.

Metal roofing panels, especially darker colors, respond to temperature change by expanding and contracting. This causes the fastener holes size to increase, and can cause leaks.

Panels screwed into metal Perling roof rafters will experience less thermal movement.

Galvanized factory-finished roofing panels and flashing materials, used in housing construction, require specific dimensions of panel and flashing overlapping and watertight sealant application between the product overlaps according to the manufacturer’s recommendations.

Exterior coatings and sealants applied to roofing panels and flashings dry out and fade prematurely, because the ultraviolet rays of the sun here in Costa Rica are intense. If the coatings and sealants are not maintained and replaced before they dry out, they will crack and allow water infiltration.

The driving tropical rains here come from all different directions and can be challenging for roofing materials that use an overlapping system of corrugated panels to keep moisture out. When rain comes at a building from almost sideways, it forces water under these metal panels that eventually ends up on the roof sheathing installed on top of the roof rafters.

Many structures in Costa Rica do not have a roof sheathing installed and the metal panels are screwed directly into the roof rafters. The spacing in between the roof rafters is open to the interior ceiling of the living areas below and any water infiltration ends up on top of the materials installed for the living area ceilings.

If the interior ceiling material selected was drywall or other porous type materials, then eventually, with sufficient water infiltration, those areas of the ceilings will appear clouded or sometimes the surface will peel off.

Selecting Roofing Products in Costa Rica – What are your options?

Metal, steel and aluminum roofing materials contain high percentages of recycled content, up to 100% in many aluminum products. Most metal roofing materials contain recycled metal. An additional advantage is that these metal products are lightweight and durable as well as easily recycled in their post-use. Metal roofing products can be made to give a shingle appearance.

Asphalt shingles use recycled, mixed paper in their base and some use reclaimed minerals in the surface aggregate. This type of material does not last as long as the others.
Recycled plastic roofing materials are available as a lightweight option.

Slate, clay, and cementitious roof materials offer excellent durability but are heavy.

Fiber-cement composite roof materials are somewhat lighter and use fiber materials resourcefully.

Variables To Consider:

Durability – How well can it tolerate the strong ultraviolet rays of the sun.

Heat Resistance – Some roofing materials retain more heat than others. If the selected product heats up, it will stay hot into the night and can affect the energy efficiency of your dwelling.

Maintainability – Exterior building products here in Costa Rica do not perform as well as in other areas that are further away from the intense equatorial ultraviolet rays. A realistic maintenance program should be organized with a knowledgeable builder who has many years of experience here in Costa Rica. Otherwise when the exterior of your dwelling leaks, it will cause damage to the interior installations as well as your personal items.

Rain Water Affect – Asphalt, Slate, Clay or cementitious materials erode and a portion of the surface aggregate will pass below to other installations and eventually leach into the ground water.

Weight – Heavier roofing materials will require stronger and more expensive structural materials.

Fire Rating – Not so much of an issue here as in North America because of the lack of federal and local regulations, however your investment and personal safety should always be a consideration when selecting building materials.

Cost– The roof of your dwelling protects all other building materials as well as your personal possessions. You should invest as much as is necessary to install a quality and maintenance free roof.

Installation Requirements – Once you’ve selected a roofing product, you should be able to rely on the manufacturers guaranteed performance for many years. Sometimes, roofing products fail here in Costa Rica because they are not installed according to the manufacturer’s recommendations. New products and their proprietary installation techniques are often not understood by the architects who specify them and create the blueprints.

It’s the responsibility of the builder to install all the construction materials correctly. The fact is that many experienced, local tradesmen have been installing traditional roofing materials according to proven installation methods for many years, but they are not normally receptive to new products and their unique installation methods.

Your builder needs to be able to communicate well with his tradesmen in their language and have the patience to educate them to respect the proprietary installation methods for the products you’ve selected.

So the bottom line is that we should spend as much money as it takes to get the best possible roofing materials installed.

Additionally, we all need to get in the habit of making sure that all the exterior surfaces on our homes are consistently maintained all year long.

Written by Tom Rosenberger. With more than 25 years homebuilding experience 15 of which have been in Costa Rica, construction consultant Tom Rosenberger knows the ins and outs of building and remodeling a home focusing in the Central Valley area of Costa Rica.

If you want to discuss Costa Rica construction with Tom, please help us to help you by using the simple form below:

Andrew Makarik

to@welovecostarica.com

Andrew Makarik is the main editor of WeLoveCostaRica, a fan of this sunny country. He is also a loving husband and a has a lovely daughter. By being a devoted family man and the biggest Costa Rica fan, he wants to make more people feel at home there. WeLoveCostaRica unites people and helps them find new home or a new travel destination. This website is a friendly community where everyone can find not only information, but also new friends and travel pals. Andrew is also passionate about IT and programming, so he himself maintains a friendly atmosphere in this cozy environment of WeLoveCostaRica.com.