Building Domes in the Philippines

  specialized equipment imported from the USA was used to build these thin shell, concrete domes that are reinforced with steel bar also in the mix of concrete is crushed marble gravel making these the only such 'Marble Domes' in the world! Built fast to last forever.....

The first day of two day plaster job. Marble Dome on Romblon Island 20'Dia.

  These domes are designed to withstand the test of time, since beyond the ability of any other structural design, the dome is superior in strength, built to withstand earthquakes, fires, even super typhoon force winds. In very wet, tropical zones with heavy rain fall, the dome is built up on a raised and compacted earth platform, even if only a few inches to allow rain water to wash away from the structure.

Cement posts 10' from the dome will support roof extension

  Building a roof cover over the dome shades the concrete from absorbing heat also sheltering the dome from rain. By extending the roof, outdoor living or working space is created. Rooms can be added onto the dome from concrete, stone or framed material including native methods of construction there by creating a hybrid structure. A roof frame or truss structure need not be made of hard wood or steel, instead bamboo poles that are at least six years in age are an excellent alternative.

Bamboo poles are attached to a hard wood frame that is secured to the dome with steel bar.

 The construction technique employs the use of a specialized industrial grade, inflatable form for the concrete to set upon for plastering the walls of the dome. After  two days of plastering the outside of the form to cover the steel, the concrete sets enough for the form to be removed. The inside of the dome can then be finish plastered. The outside of the dome is painted to create a water tight seal. Special heat-reflectant paint that has ceramic powder is best to use since concrete absorbs the heat from direct sunlight.

The inside of the dome is spacious with a high arched ceiling and obviously no dark corners. The dome is finished plastered inside then painted. The floor can be ground down then waxed with bees wax like the dome pictured here. Tile or wood flooring is the obvious upgrade but is not necessary. Windows and doors are framed in flat angle steel bar that's welded to the internal steel-bar-web-structure.    

Marble Domes 2014 Romblon, Philippines David Lubotsky, Designer, Builder

The doors and window frames in the dome pictured here are flush, only sticking out near the top of the doors. This design can be altered where door ways or the tops of tall windows protrude from the dome or include over hangs that are hand plastered over plywood forms that are set against the dome and removed after the concrete sets then finish plastered inside.

This 9' air vent hole was made to small yet is functional when dome is closed.

 The walls of the dome are vertical up to six foot then the arch begins up to ceiling height of thirteen foot and six inches. The height of the ceiling is suitable to allow for a loft yet not high enough for a living space unless creating an opening in the dome ceiling to allow for a custom build on but this will compromise the domes ability to withstand destructive forces. Obviously the more openings in the dome alter the structure dramatically yet allow natural light and fresh air inside.
The internal steel structure along with the continuous arch of the dome shape makes for many possibilities to creatively customize. The dome in its full minimalist form is the most stable and strong design possible. Typhoon, even tornado force winds with flying debris deflect off the dome.

Dome with partial roof cover, David Lubotsky 2014

 Obviously a roof structure is most vulnerable part of this type of building when subjected to typhoon force winds so it's very important that attention to the roof design prevents wind uplift.
Bamboo is very flexible and when tied together with #150-200 lb, commercial nylon fishing line, the structure is very strong and rigid yet able to flex. If the roof is to flat with not enough pitch then native roof covering made of coconut or nipa leaves will not work or last so the best alternative is a corrugated roofing panel that is flexible unlike steel. The product that is best suitable is made of recycled cellulose and is available under two brand names, Unduline also Ondura.

Reinforcing structure of the dome made with 7mm steel bar. Lubotsky 2012

  The entire dome is reinforced with steel bar at 10"spacing vertically also horizontally and tie wired at the over laps resembling a spiders web. This configuration of steel provides tremendous strength. The concrete shell of the dome is far superior to any block structure for this reason and more. The configuration of the steel also the continuous curve of the dome wall creates a structure that will potentially stand for thousands of years. Hows that for return on investment?

   When comparing costs of construction with the dome vs post and beam-cement block construction, the quality and integrity of the dome is far superior. Labor costs are far less when constructing a dome since the dome can be built in as little as seven days time. If multiple domes are built at the same site then the time can be less to construct. The overall cost may be equal, greater or less compared to a box shaped concrete block building yet the integrity of the structures can not be fairly matched since the dome is far superior.

Stone sculpture visible in the photo made by David Lubotsky as is the building. 

  The photo above shows one way of building off the dome and extending the roof to include the additional living space. In this case the posts are built ten feet away from the dome. The roof was constructed first, then the walls were constructed from the dome. This thin wall construction method is one option. Thin wall construction is made with a plywood frame that serves as the form. 7mm steel bar is tied to the plywood then steel mesh is attached over the steel so the first layer of plaster will stick. A second layer of plaster is applied. The next day the plywood is removed and the wall is finished plastered to cover any exposed steel.

Thin wall construction using plywood form.

10mm crushed marble gravel