Rainy Season Home Maintenance Reminders

The recent rain we’ve received here in Costa Rica has inspired me to remind you that this is an excellent time to pay close attention to your homes roofing, flashing and rainwater drainage systems that may need tightening up before the real rainy season begins.

The moderate downpours that are now upon us will reveal the deterioration that occurred during the summer months from intense ultraviolet penetration of your dwellings exterior building components.

Here in Costa Rica, we usually receive three to four weeks of dry weather after the spring rains and before the heavy rainy season. During this brief period of dryness, you will have the opportunity to make repairs and improvements in order to insure that your roofing and exterior building component installations are adequate to protect your dwelling for the rest of the year.

I’ve been building and inspecting housing and buildings here for over 16 years and from this constant exposure to construction here, I can tell you that 95% of the dwellings I’ve inspected have inadequate roofing and flashing installations that allow rainwater infiltration into the exterior overhangs fascias and soffits.

Previously, most soffit construction was finished with wood strips and then Fibrolit, cementious laminates became widely used. These construction materials reaction time to water infiltration is much longer than modern imported materials such as Densglass and green drywall that require installation and finishing according to the manufacturers proprietary methods.

From years of working with Costa Rican contractors, architects and engineers, I can tell you that their attitudes have been that annual painting and or refinishing of damaged exterior building components are part of owning and maintaining housing here.

I’ve suggested to them that locally available, building components can be utilized to avoid the problems, only to be told “that is the way we do it in CR.” Even though, building materials consistently become damaged following the dwellings exposure to the first rainy season.

In North America, most roofing and exterior overhang structures on housing are designed and built with construction materials that entirely enclose the structures and do not permit air or water infiltration, except where the design professionals have intentionally provided for ventilation.

Here in Costa Rica, even in expensive housing, 95% of the time there is no flashing or other materials installed at the roof edge where the gutters and or fascia boards are located. This opening between the roof structure and the finished roof covering is where most water infiltration occurs.

The infiltration of water ends up inside the overhang cavity soffit and initially causes damage to the soffit building materials in the form of mold, mildew and deterioration. After a period of time, the unsightly cosmetic damage graduates into building materials becoming saturated with moisture and then replacement inevitably becomes necessary.

A dwellings roof is one of the most vulnerable components, often times receiving significant damage while protecting everything under it from natures forceful elements. It’s prudent to seek the most suitable roofing products, not the most cost effective.

Roofing material components are very important. However, the proper installation of the underlayment and flashing are vital to the success of a complete roofing system. Some finished roofing products, are basically cosmetic applications, while the majority of the weatherproofing and insulating of the building structure is accomplished with the underlayment and flashing materials and their proper installation procedures.

The galvanized roofing panels and flashing materials, used here in Costa Rica, require specific dimensions of laminate and flashing overlapping as well as watertight sealants applied between the product overlaps according to the manufacturer’s recommended installation techniques.

Most folks do not understand that metal laminates respond to temperature change just like wood, by expanding and contracting. This causes the fastener holes size to increase, resulting in leaks.

According to the manufacturers of metal roofing laminates, panels installed over metal Perlin should not harm the roof system with thermal movement. However, I can tell you from personal, hands-on experience that the manufacturer’s installation recommendations, of attaching the metal laminates directly to a metal Perlin structure, with screws provided by the manufacturer, still expand, contract and move. I’ve seen with my own eyes, two-inch metal screws; unscrew themselves as a result of the metal laminates movement, during one seasonal change.

Additionally, zinc and hot dipped galvanized steel roofing products that are frequently used here tend to oxidize rapidly in areas of high humidity. The result of this oxidation process, especially near the coastlines and in the mountains, is the relatively quick formation of surface rust which can act as a useful barrier between metals and the environment.

However, in roofing applications, this surface rust gets washed away by precipitation and accumulating moisture on the laminates, especially when used as an underlayment below clay and tile roofing products that absorb and maintain humidity. The zinc corrosion tends to runoff with precipitation, causing premature deterioration of the roofing laminates and other attached building components. Additionally, this zinc runoff can contaminate the adjacent soil and ground water.

Therefore, in most areas of Costa Rica, especially the humid coastal and mountainous regions, it’s prudent to consider using the following anti-corrosive and waterproof roofing components:

1. Roof decking of Plycem, 14mm, 122cm x 244cm. http://www.plycem.com/ing/base_comercial.shtml or http://www.laferreteriadigital.com/fd/verDetalleProducto.do?codigo=1053021
2. Prodex insulation underlayment with top and bottom aluminum faced, 5mm, overlapped, on ridges, valleys and at least 4″ over the roofs edge into the gutters. http://www.laferreteriadigital.com/fd/verDetalleProducto.do?codigo=7018020&selected=1
3. Vertical nailers of ½” PVC tubes installed so water can pass below. http://www.laferreteriadigital.com/fd/verDetalleProducto.do?codigo=1061050&selected=
4. Horizontal nailers of ½” PVC tubes installed into first set of vertical nailers
5. Application of two coats of SUR Fastyl, anticorrosive paint onto the heads of the screws used to attach all nailers. http://www.laferreteriadigital.com/fd/verDetalleProducto.do?codigo=6019007
6. These plastic roof tiles screwed into the PVC nailers with galvanized screws. http://www.laferreteriadigital.com/fd/verDetalleProducto.do?codigo=1067136&selected=8
7. Gutters, aluminum, minimum 6″ x 6″, installed with aluminum supports screwed into the roof tiles.
8. Downspouts, aluminum, rectangular, minimum 2″ x 4″ at every corner and more on long runs.

In conclusion, all dwellings, residential and commercial, require consistent maintenance in order to maintain the exterior surfaces. The extent and nature of maintenance will depend on the size and exposure of the individual buildings.

It may be a good idea to make sure that the following basic maintenance tasks are completed before the rainy season begins:

1. Wash down exterior surfaces.
2. Re-apply exterior protective finishes that have deteriorated during the summer.
3. Maintain the exterior surfaces and connections including joints, penetrations, flashings and sealants that may provide a means of moisture infiltration.
4. Clean out gutters, downspouts, blocked pipes and overflows as needed.
5. Prune back vegetation that is close to or touching the building.
6. Clearance between the bottom edge of exterior sheathing and the finished ground cover should always be maintained.

Remember, our pride of home ownership and level of comfort aren’t fulfilled by waiting for the inevitable storms to pass. “Hasta mañana” is a local tradition that most foreigners have been exposed to. However, in order to survive down here in the jungle, property owners need to learn how to deal with Costa Rica’s unique climatic characteristics and how they impact our dwellings.

Consistent preventative maintenance will go a long way in protecting your property investments.

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Written by VIP Member Thomas Patrick Rosenberger of CostaRicaHomebuilder.com With more than 28 years of homebuilding experience, 18 of which have been in Costa Rica, construction consultant Tom Rosenberger knows the ins and outs of building and remodeling a home in the Central Valley area of Costa Rica. You can contact Tom using his Contact Us page here.

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.