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3 Things Homeowners Should Know Before Replacing Their Roof

By Molly J. Parris

Many builders are aware of current attic ventilation, insulation, and roof drainage requirements, but homeowners who want to tackle a roofing replacement on their own, or those who are in negotiation with a contractor, may be better served by being aware of a few well-documented recommendations.  Considering most roofing contractors are capable of completing a residential re-roofing project in a single day with little input from their client while a DIY endeavor may require careful planning, timing and execution, an understanding of the components of the entire roofing system is important. 

The Commonwealth of Massachusetts’ 8th Edition Building Code, available on the Commonwealth of Massachusetts’ official website, outlines attic ventilation requirements, generally including soffit venting balanced by equal air exchange at the roof ridge.  This code is a good reference for experienced do-it-your-selfers who are comfortable installing intricate flashed openings, but can also educate homeowners when establishing a scope of work with a roofing replacement contractor.  Installation of soffit and ridge venting should be included during a roofing project if the house has not yet been updated.  For architects, many housing buildings or private homes undergoing their first comprehensive roofing renovation may not have adequate attic venting conditions and updating this system is important.

Individual municipalities in Massachusetts now have the option to adopt the Stretch Energy Code which is an Appendix to the 8th Edition State Building Code and provides guidelines for optimum energy performance in various building systems in new residential construction, new commercial construction, and renovations or additions to existing homes.  The Stretch Energy Code is available for PDF download on the Commonwealth of Massachusetts’ official website and can provide a valuable tool for homeowners within or outside participating municipalities who would like to check their contractor’s material selections or who simply desire to get the most out of their roofing investment.

Drainage capacity requirements have also become more conservative over time.  The U.S. Department of Housing and Urban Development has published a guide titled Moisture-Resistant Homes:  A Best Practice Guide and Plan Tool for Buildings and Designers With a Supplemental Guide for Homeowners.  This publication is available for free PDF download and contains simple instructions and a quick calculation to assess the appropriate gutter size, number of downspouts, and downspout size for optimum storm drainage (modified per U.S. region) from a given roof plane.  If a roof and downspouts have not been replaced in twenty or thirty years, it may be wise to evaluate whether or not the existing number of downspouts is adequate.  There are several accepted standard practices when it comes to residential storm drainage, but a majority of homes are affected by water intrusion at grade.  Relatively inexpensive solutions such as perforated drain lines laid below grade can combat slope issues, solve interference of new downspouts with adjacent hardscapes, and can be targeted to water vegetation. 

A house’s roof is much more than plywood, flashing, and shingles.  It serves to direct water, snow, ice and debris away from the structure.  The slope required forms an attic and redirected water must end up somewhere.  Venting, insulation and drainage are components of the whole roofing system.