As part of our work at the Three Links Apartment project we are doing some water control and below grade energy work. This involves excavating around the perimeter of the building and installing a drainage system. The drainage piping pitches toward a natural exit. Some areas of the existing soils were fairly good, with a high granular content, but other areas were heavy with clay mixed in. When a building has clay pushed up against the foundation water can pool against the foundation and even create damp interior floors. We add clean granular fill material around our drainage system to ensure water has a positive path to drain from the site. We are also re-grading many areas around the building to create natural waterways so surface water can migrate away easily.
While we have the foundation exposed we are adding below grade insulation. We apply the insulation horizontally under ground, then extend it vertically up the face of the foundation. We protect the exposed area of the insulation between the final grade and the start of the siding material with pre-finished gray metal. This building was constructed during a time when below grade insulation was not required nor was it a normal practice. When our Minnesota soils freeze hard during the winter the floors in this type of building become cold at the perimeter and the building experiences a heat loss. By adding rigid insulation we help control the heat loss and improve the comfort in the building.