To Vent or Not to Vent

Vented attics and crawl spaces are the typical practice for homes and have been for years. In this blog we discuss why encapsulation is the better approach.

Vented and Non-Vented Crawl Spaces – The purpose of venting a crawl space is to provide air movement under the home for any trapped moisture to dry out and avoid mold issues. The building code identifies several criteria in order to achieve proper cross ventilation. Cross ventilation is becoming more difficult to achieve with the trend of outdoor/indoor living. Many homeowners are choosing to go with large porches which many times block areas of potential ventilation. Often mold accumulation happens in corners and other areas with less air movement. The real question, however, is why allow for heat and humidity to enter the crawl space at all? Crawl space encapsulation essentially makes the crawl space a part of the conditioned space of the home sealing it from the exterior elements. Encapsulated crawl spaces, when done correctly, have proven to prevent mold and moisture issues. In addition, the homes are more energy efficient because they are not having to heat and cool the air circulated through the crawl space and up into the house. So why are people still choosing to vent their crawl space? The answer cost. Although the cost is not astronomical, it is not free. Because of the cost, sealed crawl spaces are more common on custom homes versus homes built to sell.

An Alternative Method – To maximize cross-ventilation some home builders and designers are using continuous crawl space vents. This new system provides a long, continuous vent along the sill plate. See more information at


Vented and Non-Vented Attics – In most older homes when going into the attic during the summer you will find two things. One, the insulation is located on the attic floor or ceiling of the home and two, it is unbelievably hot and humid. Venting the attic increases the longevity of the roof finish by preventing the attic from getting too hot. But even a well-vented attic can reach up to 150 degrees Fahrenheit during the summer months. Attic encapsulation uses spray foam insulation attached directly to the underside of the roof sheathing to allow for the entire attic to be a part of the conditioned space. Because the spray foam insulation is a part of the roof assembly the attic is no longer subject to the greenhouse effect and there is less concern about roof finish longevity. Attic encapsulation is also more energy-efficient given that this large volume of hot humid air is no longer trapped between your home and the exterior. Now you can grab those old photos out of the attic without having to worry about heatstroke or melted photos.

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