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By PETER KULCZYK, Green Code Knowledge
Have building and construction questions? We have the answers! Peter Kulczyk of Green Code Knowledge, a building industry expert and frequent instructor at Contractor University, is available to answer your questions.
A. Yes. The Minnesota Residential Building Code, in Section R501.3, “Fire Protection of Floors,” now requires floors constructed with other than 2 x 10 solid sawn floor joists to be protected on the bottom side with ½ inch gypsum board or 3/8 inch wood structural panel that serves as a means
to provide an extra margin of safety during a fire rescue mission. There are some exceptions for crawl spaces, utility areas and alternative engineered joists that can be considered. This code section does not require any joint treatment or address vertical penetrations through this membrane.
A. Not necessarily. IRC Section R317, “Protection of Wood-Base Products,” requires that foundation sill plates that rest of a concrete or masonry exterior foundation wall and are less than 8 inches from the exposed ground be preservative-treated or be a naturally durable wood, such as Redwood, Cedar, Block Locusts and Black Walnut. In other words, if the foundation is 8 inches or greater from the exposed ground it can be of any species recognized by the code structurally capable of carrying the load above without being preservative-treated or naturally durable wood. Some code officials recognize that the use of a sill sealer between the sill plate and the foundation wall provides the separation needed to prevent moisture from being absorbed by the sill plate. Check with your local code official.
A. No. The State of Minnesota amended IRC Section R310 to include some wording that addressed this situation. It basically states that window replacements are exempt from the minimum net clear height (24 inches), net clear width (20 inches), and net clear overall size (5.7 square feet) as long as the replacement window is the manufacturer’s largest standard size window that will fit into the existing rough opening and of the same operating style or a style that provides for an equal window opening area. For example, under this provision, if an existing sleeping room only had 24 x 24 double-hung windows then the replacement windows could also be 24 x 24 double-hung windows (even though they would not meet the 5.7 square feet needed for windows in newly constructed homes).
Yes. IRC Section R305.2, “Alterations to Existing Basements,” only requires that these proposed rooms have a minimum ceiling height of at least 6 feet 4 inches and that the stairway has the same.