Testing it out for Myself
By Tim Peck, OBM International
Construction in the BVI can be very challenging in terms of budget, quality and the time it takes to build.As architects, if we’re going to experiment with new materials and construction techniques, perhaps it’s only fair to try them out on ourselves before trying them out on our clients' projects. I reviewed a number of construction systems for my house at Ballast Bay, balancing tried and tested local skills with recent advances in construction systems, and opted for the Nudura Insulated Concrete Form (ICF) as the primary structural system for the house. The ICF system offers a reinforced concrete structure in combination with very light 8’- long by 18”-high foam panels that are easy to handle around the site.
Tim Peck tested new materials on his own house to pass on to his clients.
These panels have two 2 ½” layers of polystyrene connected by plastic webs, which leave a 6” cavity to be filled with reinforced concrete on site. The system is neat and sophisticated, with corner elements, end caps and interlocking fasteners as part of the kit, and can be quick to assemble, but the critical element which must not be overlooked is the bracing. The package comes with proprietary steel framing to brace the foam forms, and it is vital that these are well secured and are plumb and square, or it will certainly come back to haunt you later in the process.
The system works most efficiently if you rationalize the design to work with the ICF modules. I had developed a relatively simple plan, but I had introduced some architectural “gymnastics” with some of the structural openings, particularly the open-corner sliding glass doors which required some complex reinforcing detailing by the engineer. These design elements were important to me, and the system was flexible enough to accept a hybrid mix of traditional forms, where necessary, alongside the ICF formwork.
A benefit of the ICF system is the separation of the trades. once the filled foam block is in place, the electrician and plumber can attack the inner and outer foam layers with a hot knife to route their piping, thus reducing hacking and patching. This was particularly important for this house, where I had decided to opt for aspects of smart house technology, with a complex web of conduits home-running to a central hub to control some of the home’s electronic systems. To fully take advantage of this rationalization of trades, all parties must have planned their primary distribution routes through the concrete slabs and that these stubs appear in the thickness of the foam, not within the concrete core of the wall. The inner surface of the wall, and its mess of conduits, is then covered in sheetrock and finished with sheetrock compound to give a smooth, refined finish. The exterior surface is covered in a proprietary plaster, fiberglass mesh and a precoloured stucco.
The IFC system is excellent at addressing all aspects of sustainability, contributing to leed certification in many ways. The foam blocks are manufactured from entirely recycled and recyclable materials. The material does not support mould growth, has no air quality toxicity problems, and the use of the two layers of foam insulation offers 70% energy savings in a comparable Us market. one additional aspect that is particularly relevant to the bvi is that the 6” reinforced concrete core offers significant durability and can meet seismic and hurricane codes, which, combined with the appropriate choice of window and door systems, can offer peace of mind in hurricane season.
The quality of the end product is testimony to the quality of the construction system and the ability of the contractors to accept a new approach. The house remains cool, and the bedroom areas are quick to respond to air-conditioning, if ever required, keeping utility costs low. We wanted to feel good about the quality of the environment that we were creating at ballast bay and also to sleep well, knowing that we have minimized any potential negative impacts on our global environment.