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Question
I own a ranch home and recently noticed that a few of the floor joists are grade 3 lumber. the majority of the joists are grade 2.The home was built in 1977. the joists are 2" x10" x 12 foot long. should I have any concerns as to the structural integrity of these number 3 grade joists. Do they need to be replaced with number 2 grade lumber.
Hello John,
I assume you are reading a stamp on the joist. The species of wood may be graded differently. The difference between Grade 2 and Grade 3 is generally in appearance. Grade 3 may show more knots. The Grading is frequently done by visual inspection although electronic devices can be programmed to detect variations that would serve to classify the grade.
Structurally you do not have a problem. The size you describe is within limits that the joist can span. At 40psf live load and 10psf dead load, a Grade 2 can span 16'-1" and a Grade 3 can span 12'-2". Even if it was determined that a better joist would be advised, the existing joists would not have to be removed - rather, new joists could be installed next to the existing joists and anchored properly. Also a plywood sub-floor or decking properly nailed will distribute the live load over several joists.
I hope this has been helpful.
Roger
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Roger Zona
Expertise
I am experienced in all types of construction: residential, industrial and commercial; single family, multi-family, mid-rise and high rise buildings (16 story office building) as well as remodeling, additions and tenant improvements. I can field most any question that relates to general construction. I have consulted with infrastructure (utility) contractors also and have a good general knowledge of underground utility construction for subdivisions and commercial projects.
Experience
After college, I began my career in the construction industry. I chose to become an apprentice Architect and 4 yrs later I opened my own architectural design firm. Six years later I moved to Florida to buy & develop land and build. I became a State of Florida Certified General Contractor and operated my business for 45 years. I built all types of residential and commercial buildings including warehouses, shopping centers, high rise apartments and office buildings and developed sites for other contractors. I retired and became a consultant to the construction industry. I maintain my license and continuing education requirements, operate a small construction company and write a weekly newspaper column for the Palm Beach Post (a Cox publication) with the byline "Ask The Contractor". I am the "technical editor" for a publisher of books that relate to home maintenance.
Organizations
Previously - NAHA
Currently - FLCA (Florida Licensed Contractors Assoc.)
Publications
Palm Beach Post newspaper - weekly Q & A column
Happy Herald monthly real estate publication - monthly column
Education/Credentials
Michigan State University
University of Detroit
BS in Engineering
Past/Present Clients
I built a home in Palm Beach for a member of the Pulitzer Family.
I was responsible for the completion of a twin hi-rise condominium project for G.E. Credit.
I was a partner in the successful development of a P.U.D. (Planned Urban Development) subdivision.
I represented the largest home builder from France (Bati Service, S.A.) in the development of a subdivision and the design and construction of the homes.
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