Insulation, Air Sealing - Ventilation and Attic Insulation, Mansfield, MA

For many years it has been common building practice to construct a roof system with two key elements as per code requirements.

1. Install proper ventilation as defined as one square foot of open air ventilation for every 100 square feet of attic floor.
2. Insulate the attic floor with a minimum of R-19.

Recent codes have increased the insulation requirements in new construction for cold region climates to R-30 or better. Although the insulation code increases have helped save energy when installed properly, the ventilation requirements are not as easily defined as there are many different roof designs and slopes so various ventilation approaches must be taken.

When your roofer shows up to look at your roof he will follow the same standard recommendations consistently each time. Replace your roof, install an ice and water membrane, and install roof vents or a ridge vent. Sometimes the roofer will also recommend ventilation at the eaves by drilling holes in the soffits to give an air path way to the ridge vent.

The purpose of good ventilation is to release the excessive heat that rises up from your conditioned space or heated space from the lower levels of your home. The main goal is to have the air temperature inside the attic be close as possible to the outside air temperature.

In theory these methods are good procedures but the million dollar question is why do we still get ice dams and mold and mildew if all of the proper steps have been taken? Is our children's health at risk with the rising Asthma related illnesses due to sick home syndrome? http://www.epa.gov/iaq/index.html

Prior to the early 1980’s builders and roofers did not use ice and water membranes because they did not exist. Older homes were not built as tight homes and balloon framing was common until the late 1940s. Ice dams were not a common problem in these older homes because they were so inefficient. Ice and water membranes were invented to help offset new home designs but work sporadically and are usually band-aids to chronic air problems in the attic and not always the solution. As home construction and remodeling methods have changed and making homes air-tight as possible is the new mandate with high efficient windows, increased minimums for insulation, insulated vinyl siding etc. etc. conditions inside the home change which in turn changes the dynamic of airflow and in theory should make ventilation requirements change as well.

Many contractors will recommend added ventilation such as wind turbines, electro-mechanical ventilation, whole house fans, etc. and yet still do not solve the mold or ice dam problems in fact sometimes make them worse. The homeowner is left with and inefficient home with ice dams and or mold and mildew even though they have insulated, ventilated, installed new roofing, and painted and repainted their eaves and ceilings.

Mold is now also becoming a problem in many residential and commercial buildings with similar symptoms. Mechanical ventilation while necessary in some cases may cause your air conditioning units to run less efficiently because these high CFM (cubic feet of air per minute) fans or air pumps draw the air from the space you are trying to keep cool. As the air is removed it needs to be replaced from lower levels of the home such as the basement or from outside air infiltrating through sill plates, windows, doors, electrical outlets and any other penetrations on the outside wall. (see stack effect)

Even the insurance companies are at a loss as to how to solve these chronic problems in homes and in most cases removed mold removal as part of homeowners insurance coverage.

Call (508) 619-4167 for a free evaluation of your home today. Email us at info@yourhomeexteriors.com