Advantages
As seen from the Design Factors page, these houses are designed to utilize labor and materials very efficiently and with minimal waste. This has many advantages in constructing these homes.
The crew
Compared to other construction techniques, the crew is very small, typically four to five men, the number needed to lift the roof sections into place. Compare this to a block or cement wall house using a crew typically 8-12 persons for 12 months and often longer to finish, than this design. The crew is working with a project book showing the details of each component, plumbing, and electrical designs. Repetition and familiarization speed the process and maintain consistent quality. Utilizing molds and other pre-cutting and pre—fabricating techniques, we are basically running a portable factory, not a construction site. In fact, in the near future, most all of these houses will be able to be prefabricated and shipped to remote sites ready for assembly.
- Less labor spent transporting and loading the job
- Less time spent with unnecessary custom cutting
- Less time spent cleaning the site and transporting expensive materials to the dump
Molds are extensively used in this construction. Compare this to custom houses where lots of time is spent getting materials and doing custom work on designs that are not material efficient.
The Foundation
Reusable, pre-cut, form boards, supports and molds make quick work of foundations. The foundation uses re-useable forms that are attached to a larger mold to assure foundation is square and level. The octagon section uses pre-cut forms connected to welded angle supports to assure a perfect, level octagon foundation and floor. Bolts are anchored below all posts to bolt down the posts to the floor. Walls use a nail gun to anchor them to the floor. The foundation is a “floating” foundation (see Design Factors page for a descriptions) and is a much easier and faster foundation to install.
Compare this to a standard Block foundation which needs 3 ft. deep post and pad supports with a lower and upper seismic beam to support the weight of the building for seismic purposes.
Plumbing & Electrical
Plumbing and electrical are designed with superior quality products that make installation faster.
The plumbing system is designed to reduce length of piping, efficient placement, and more than ample slope to assure good drainage.
Multiple vents are extended through the roof and out exterior walls to provide adequate venting for proper toilet function. These vents exit under eaves to eliminate roof leaks at the vent pipe exit site.
The PEX water system is rated for in concrete slab placement, but never touches concrete, to assure a lifetime of leak free water piping. This system assures minimal joints above slab and absolutely no joints below the slab! PEX piping is the only plastic piping allowed in or under a concrete slab floor by the IBC building codes. Compare this to the standard PVC piping typically installed in and or under the concrete slab. PVC is very brittle compared to PEX and can break making leaks difficult to impossible to locate and very expensive to repair. This PVC system design also uses a lot more water to get hot water to a fixture.
Most electrical is above slab. We install an additional 1 ¼” conduit to the main panel for future addition of solar or backup generator applications. We use Romex, which does not require conduit and is standard in North America and Europe compared to conduit in slabs and walls which uses more materials and time.
Structure
Posts, walls, roof sections, cupola octagon, and other components are built in molds and bolted and screwed together to make the structure. Then the structure is skinned with ceiling, insulation, roofing, windows and siding.
All posts are prefabricated using pre-welded connection systems that are cemented into the ends. The posts are ready to bolt to the foundation and the bamboo roof structures.
In octagon designs, the cupola octagon section has ¼” flat steel welded frame inside the bamboo and is inserted into the cantilevered bamboo beams and bolted in place.
All walls are pre-manufactured in molds with cross bracing attached and holes for electrical and plumbing where required.
All roof sections are made in molds, cemented together, all thread installed, ready to lift and bolt in place. Working at a comfortable height increases speed and quality.
Once the foundation and floor is poured, the structure can go up as the roof sections are completed. There is some custom bamboo decorative trim that takes place to finish the cupola, etc.
The structure from foundation to weather proof roof is very fast relative to other construction systems as a result of the modular prefabrication system where we utilize forms and molds to manufacture the major construction components.
Compare this to an expensive, time consuming, heavily built and reinforced foundation to support heavy concrete walls that take much longer to build, and stucco leaving a difficult to surface smoothly. Roofs that are custom cut and welded in place high above the ground.
Roofing, insulation and ceiling
We use a ceiling, insulation, roofing system that is unique in its structure, its speed, and ease of installation.
Before the entire wall and roof structures are completed, installation of the “Machimbre” or treated tongue and groove (T&G) ceiling can start. Immediately after installation, the T&G is covered with a tarpaper, which is a standard roofing underlayment. At this point the structure is “under roof”. Then 2X2 treated pine and 4X8 ft sheets of Styrofoam are installed. This allows the roofing a secure attachment with a solid backing. The zinc roofing is ordered in the sizes needed so there is little waste.
Extra wide neoprene washers with metal covers are used to attach the zinc roofing and sealed with a final polyurethane caulk and elastomeric paint. Compare this to a standard roof using carriolas welded in place, and difficult-to-impossible to place ridged insulation and roofing. Therefore, these structures are typically insulated with a thin, very low R value, foam or bubble wrap insulation with little soundproofing capabilities. Typically, ceilings are usually flat not vaulted making it impossible to have natural light, a more closed feeling, and faced with either sheetrock or a suspended office style ceiling.
Plycem siding and gypsum wallboard
The walls are designed for minimal waste of these materials. This means less cutting and less seams to tape and seal. An exterior vapor barrier is installed prior to the plycem installation.
Plycem is a fiber cement board widely used in modern construction to replace wood siding, plywood, tile base in showers, and where needed, sheetrock. Plycem is manufactured in Costa Rica.
This exterior siding product replaces many wood products with a lower embodied energy product than block and stucco, that will last far longer than wood in any inclement situation such as continuous exposure to weather, roof leaks or other moisture sources, and insect damage. The cement board is reinforced with fiber. In its siding form, it is textured to look like wood. It will accept wood stains and paint and both will give the appearance of wood siding. It can be spackled and taped like sheetrock for smooth wall finishes. We use an acrylic commercial stucco finish.
The embedded fiber reinforcement means a strong, durable product with less thickness than wood and less weight than stucco finishes. Plycem comes in different styles and thicknesses, some suitable for framed floors and decking. These products are designed to be screwed into steel studs and floor joists. These steel components replace wood studs and joists typically used in North America. Here they are called carriolas, a steel “C” channel or steel stud. These come in different gauges depending on their use in a home. We use only the structural rated gauges for all studs. These products can replace plywood for floors, when placed on floor framing using carriolas.
Compared to other systems, like concrete block, this system significantly reduces the weight of a building, up to 80% less. This means a lighter, stronger, more flexible structure that will require lighter foundations and supports, and will withstand earthquakes far better than a heavy, rigid, concrete structure.
Carport and Patio covers
We utilize the same design for these structures. They are free-standing structures and are not connected to the building. They cover the existing roof and a section of gutter is used to provide drip-free access during rain. The size of these covers can easily be modified.
Speed of construction
We are always working on ways to reduce construction times without affecting quality or appearance. This construction system uniquely lends itself to the ability to accelerate the process.
The roofing can be started before all the walls and structure are complete. 95% of all plumbing and electrical is located at the rear of the house where the walls and roof are first completed. This means that the plumbing, electrical, and plycem exterior can be started before the roof framing is 100% complete. Once the roof is done, the rest of the project is left to the subcontractors. With square flat foundations, floors and rooms, installation of tile, cabinets, and doors is easier and faster.
We are looking at completion times in well under six months as we refine our techniques. Compare this to many months spent building foundations, walls and stucco, chiseling in plumbing and electrical lines, installing roof framing in the air, not on the ground, where sheetrocking and taping a ceiling are working over your head. Our system is designed to use gravity.