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This closed-cell SPF product offers a maximum lift thickness of up to 3” in a single pass, providing an R-value of 19 at 3” and R-39 at 6”.


 


Foam Board: How Green is it?
From a strictly front-end perspective, the materials in foam board are not as “green” as cellulose or arguably, fiberglass (which is made from sand). Foam board, whether polyisocyanurate or polystyrene, requires a lot of fossil fuel to manufacture.


“Polyisocyanurate and expanded polystyrene tend to use less harmful blowing agents than other foam boards,” notes Todd, “and open-cell spray foams tend to be water-based, which is good.”


As Colwell points out, foam board can make a stronger argument for sustainability from the perspective of how much energy it will save over its lifespan. The occupied stage is where about 94% of a home’s overall environmental impact occurs, so foam’s high performance carries a lot of weight.


 


A RIVER RUNS THROUGH IT
While it may be tempting to address basement moisture control issues with an inexpensive interior membrane or coating, experts warn that this is not a good, long-term solution. Because the water doesn’t drain, as soon as the membrane deteriorates, the moisture will inevitably find another route into the basement.


This being the case, interior perimeter drainage systems may be the best option if condensation is a serious issue for particular locations.


Offering an overview of three basic types of interior drainage channels, experts at the University of Minnesota outline the following:


> Above the concrete slab. As the easiest, and least costly approach, drainage is installed at the base of the wall and floor slab where it collects water and drains into a sump pump. While this a good strategy for concrete walls, it doesn’t work well with masonry.


> Within the slab edge. Ideal for concrete masonry walls, the drainage channel is placed at the base of the wall on top of the footing. In addition, holes must be drilled into the base of each block core to enable full drainage to the sump. However, the core tops need to be capped, and a vapor-retarder coating must be placed on the interior basement walls.


> Beneath the slab. Considered to be the most effective interior drainage system, perforated drain pipe is installed inside the perimeter of the footing with dimpled plastic sheeting placed at the wall’s base beneath the slab edge for optimized drainage.


 


Placed above the concrete slab, the drainage channel within this interior perimeter drainage system drains to the sump pump to control moisture in the basement.

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