KEEPING DRY - FOUNDATIONS

"Concrete waterproofing is generally defined as the ability to prevent water from permeating through concrete against sustained hydrostatic pressure, whereas damproofing products only retard moisture penetration under non-hydrostatic conditions," says Les Faure of Xypex Chemical Corporation.

Crystalline Technology is applied to waterproof foundations. Photo provided by Xypex Chemical Corp

Waterproofing products for foundations are often petroleum based or require excavation and backfilling to apply to an existing structure. Concrete is a porous material and new admixtures and applied coatings are now available which will waterproof a structure without the use of petroleum. These coatings can be added directly to the concrete mix and permeate the concrete foundation. They can also be applied to an existing foundation and the chemical reaction of the coating will be drawn into the concrete voids of the concrete.

Crystalline coatings are non-toxic, have low VOC's, and do not affect the recyclability of concrete. Because it is a coating and not an applied material to the foundation, there is no construction waste. It can be applied to both the positive and negative side of a foundation wall to provide waterproofing. These coatings are primarily designed for vertical applications and if tile is to be applied to the coated wall, a special bonding agent may be required for proper adhesion. These waterproofed foundation walls still provide permeability for air vapor and have a high perm rating.

Foundations should be insulated as well as waterproofed, to provide thermal protection, even though often the ground temperature is above freezing. In particular, most housing professionals know the importance of applying insulation in between the joists above foundation walls where substantial heat loss can occur. Some manufacturers provide home energy saving calculators and recommendations for home insulation which will comply with the EPA recommendations for an ENERGY STATAR^® home.

CONCLUSIONS

In a world where images of sliding polar ice caps are in the news, many owners and their architects are seeking to design buildings which contribute to solving the problems of global warming. The EPA reports that heating is the number one use of energy in buildings and is responsible for over 1/3rd of the buildings energy budget. Almost half of all US total energy consumption can be attributed to the building sector.¹⁸ "Every time we design a building," says architect Ed Mazria, AIA, "We set up its energy consumption pattern and its greenhouse gas emissions pattern for the next 50 to100 years. That's why the building sector and the architecture sector are so critical."¹⁹ The design of the building façade is just one piece of the energy puzzle for designers. Some designers are now working on a goal of zero-net energy in buildings, by minimizing energy used and maximizing alternative energy sources. Just filling the walls with insulation is not the answer although it will reduce the use of energy in buildings. Smart design will integrate systems to provide both high thermal performance as well as moisture protection.

The architects dream is a building enclosure that will act biologically like our skins. This enclosure will heal itself, breathe air and moisture, clean environmental pollutants, allow sunlight and not glare. This new building skin will add oxygen, deliver lighting, absorb toxins and purify them as well as maintain heat or provide coolness with the season. The future may already be present with the careful integration of all building systems using existing materials. In the twentieth century, the goal of architect LeCorbusier was to create a house which was a "machine for living", today's architects are designing buildings as machines for breathing.

Celeste Novak, AIA, LEED AP, is an architect and writer specializing in green design and community planning.