Bamboo is one of the strongest building materials in the world. It has twice the compression strength of concrete and roughly the same strength-to-weight ratio of steel. It withstands up to 52,000 pounds of pressure in compression. Bamboo’s tensile strength is 28,000 per square inch versus 23,000 for steel. The hollow tube shape gives a strength factor of 1.9 times more than an equivalent solid wood beam.
Bamboo houses are able to withstand hurricanes and earthquakes. Bamboo Living Homes withstood three hurricanes with winds at 173m.p.h. in the Cook Islands in Polynesia in 2005. By contrast, most of the wood frame houses on the island were damaged beyond repair.
All of the twenty bamboo houses built for the National Bamboo Foundation survived a 7.5 Richter scale earthquake in Costa Rica in April 1991. An earthquake in Colombia in January 1999 also destroyed 75 percent of the buildings in the region, however, the bamboo structures survived uniformly unscathed.
Light structures made of bamboo, or wood, with standard sidings like fiber-cement board (Plycem), or plywood siding and interiors of gypsum (Sheetrock) handle earthquakes incredibly well. They are systems that have been used for generations in the US and Europe, and are well proven. They are low embodied energy products especially compared to concrete block and structural skin panel systems.
The walls we will use to fill in between the bamboo structure will be steel studs with sheetrock interior and a plycem siding exterior. Plycem is a fibercement board made in Costa Rica and throughout Latin America. Similar products are widely used in construction in the US as well. They offer a thin, strong, siding that looks like wood and can be painted and stained. It is impervious to water, rot, and insects. These come in 4X8 sheets or in 8 foot siding planks. Our designs attempt to minimize waste, and the labor to cut and install these materials. These types of walls also allow for some customization to the house. The wall structure allows for the customer to have more choice of windows, doors, exterior siding. We have an allowance for the costs of the windows and doors we chose, but other ones can be purchased for an additional amount.
This system allows us several advantages over local systems of concrete block, or even the M-2 style structural skin panel systems (a far superior system to concrete block).
This system is far lighter, a fraction of the weight of a concrete block or structural skin panel buildings. The walls are hollow, which means you can use romex wiring without conduit, chiseling walls, etc, and you can insulate the walls if you are in a cooling or heating zone. Plumbing is also much easier to install and access.
FOR MORE INFORMATION ABOUT PLYCEM SIDING AND OTHER PRODUCTS see our Plycem Fiber Cement Board Page
We will be using PEX water piping system, which means no joints in slab floors, and it is much more flexible and durable than PVC piping. PEX is widely used in the US and Europe. It is rated for hot and cold waters and comes in long rolls. It is the only pipe allowed in a concrete floor by code in most of the USA. I have used PEX piping for 20 years in hydronic (warm floor) heating installations in concrete floors. It is a premium system, that is worth every penny extra. Each bathroom will have a minimum of sewer 2 vents tied together to meet one of the 7 US building codes requirements. Sub grade sewer plumbing shall be to US codes, this means all lateral piping shall use Y’s and 45 degree ells, not Tees. Clean-outs installed at easily accessible locations.
These may seem like small details, but these are some of the things that will make these houses problem free for years to come. They are also much easier to install, reducing labor costs.
It is an important part of the home, and one of the most expensive parts of the structure. Roof leaks are not fun, and with up to 20 feet of rain per year, no one wants one, including us, the contractor!!!!
We offer two types of roofs for the main body of the roof.
The least expensive of the roofing systems here in Panama will always be a sheet metal roof. These are the most typical roofs here in Panama and they have their pluses and minuses.
On the plus side:
- They are easy to install.
- They have fewer leak problems than most other roofs if installed and maintained correctly.
- They can be painted different colors and there are good elastomeric paints that will seal as well as protect.
- You can paint them with light colors, or in hot areas special highly reflective white to reduce heat gain.
On the negative side:
- They are HOT! Especially if they are painted a dark color, like red, and have little or no insulation. These roofs absorb solar energy and turn it into an infrared heat wave, which can penetrate even Sheetrock to heat everything inside the building envelope. However, this downside can be managed with some intelligent design and extra insulation and light or white roof paint.
- They are noisy. When it rains, without insulation, or with only just a little insulation, they can be very noisy. And it’s not just the noise from the roof above the house, it’s also the noise from the eaves that penetrates through the windows. This downside can also be managed with some intelligent design and extra insulation.
Asphalt Shingle roofs:
Rarely seen in Panama, however, they do sell them here. Widely used in the USA, and probably the most common roof in the USA. Product technology has improved so that the warranties are 40-50 years, (or your lifetime, whichever comes first) and they are textured, to look like wood shakes, with a variety of colors and shades.
They are easy to install, and have sealed tabs so they will withstand winds to 120 miles per hour. Much higher than a class 1 Hurricane. They look nice. They are probably the most reliable leak wise. But like everything, it comes at a price.
These shingles have some installation parameters that will make them cost more to install, but some of these parameters also offer significant advantages that offset these costs. The substrate has to be of a certain kind. This means plywood. If we use plywood, it must be treated on both sides using the same treatment we use for the bamboo, (and ecological termite contractors use in the USA) before installation. Cut seams also need treated. See Bamboo Treatment page for more details on this.
There must be a vented air space between the plywood and the ceiling. This can be a crawl space, but we want to enjoy the open high ceilings, so it will be a 1” space between the plywood and the insulation over the ceiling material (whatever that is). This space must vent at the ridges and ends of the roof. This means some simple sheetmetal flashings and ridge vents.
Why does it need to vent? Because if it does not vent (breath) moisture will build up in the plywood and it will rot. This is true in Panama, Florida, Arizona, or Alaska! It is OK to build up some moisture (condensation) during the winter (wet season) BUT it must have a chance to heat up and dry out during the dry season.
This system obviously will use more materials, and labor to install them, but that’s a one time expense, and you get a few rewards for this.
Asphalt shingles are a dense material, so they absorb sound. The plywood is also an insulator, (does not transmit heat well) and its dense so it absorbs sound. The vented air space we created does a couple of great things. It further decouples the noise from the ceiling, making this a relatively quiet roof. It also vents the heat that passes thru the plywood, reducing the transmitted heat thru the (thinner and therefore less expensive) insulation and ceiling material resulting in a cooler home. Lighter colors also help significantly in the reduction of transmitted heat!!
Other roofs, like Ceramic Tile, are too heavy and too costly. Too much weight up too high making structural costs to support not only the weight, but the weight in an earthquake less cost effective. We will not offer this option.
Fibercement roofs are heavy, costly, brittle, and unfortunately the only ones we know of available in Panama are made with Asbestos. Sawing asbestos roofing (making asbestos dust) and installing it in peoples homes does not sound good for the employees, the environment, the clients, the community, or the contractors. Its also difficult to make it fit our designs. Asbestos-free fiber cement roofing is available in Costa Rica, it’s made with Polypropylene fibers and is a better product, but expensive and difficult to get here.
The plastic tile roofs, which we like, are incredibly expensive and in installations have been hard to seal where there is a driving wind, like the mountains of Boquete. So they are off the list.
Flat plycem roofs with taped seams: We are looking into these. On small structures they make sense, on large areas, they would be more difficult to make attractive, so they lose on the beauty scale. Also not proven yet, though we do not see a problem and intend to use them in appropriate areas where they will be cost effective.