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Expert: - 7/1/2009


Question
QUESTION: I recently purchased an above ground 9' x 15' swimming pool. I would like to place it on our deck. The deck is pressure treated 2x8x16's on 2' centers. The total gallon capacity of the pool is 2,200 gallons. By my calculations that equals 17,600 lbs. which divided out over the square footage would be 135 lbs/sq. ft. Will the deck carry this load?

Thank you!

ANSWER: Hello Debra,

Your calculations are close.  The 9'x 15' pool equals 135s.f. Divide the total weight including the pool frame and water and that is approx. 133#/s.f. -  but I wouldn't advise putting that much dead load on your deck unless it has extra supports.  The construction you quoted is suitable for normal live loads - approx. 35#/s.f.

You could consider cutting the deck away from where the pool will sit and supporting the bottom on clean sand.  A carpenter could cut the joists and decking and then frame the opening to support the cut ends.  

I wish I had a better answer for you.

Roger

---------- FOLLOW-UP ----------

QUESTION: Thank you so much for your rapid response! I'm curious, if the deck was built with 2x10x16's what would the live load capacity be? Unfortunately the deck is not located at ground level (daylight basement with deck built off the first floor) and we would need to determine how many extra supports we might need to support the "live load" of the pool.

Thanks again!

Answer
Hello Again Debra,

The 2" difference wouldn't improve the live load significantly.  What would help - shorten the span.  16' is about the maximum for a 2"x8".

I understand your plan better now.  The deck is suspended above the grade about 8' and is supported by the house on one side and posts and beams on the outside perimeter.  

You could add more posts and beams and thereby reduce the span of the joists.  Lets assume two more beams at 1/3 spacing - the span would now be a little over 5'.  Now you are approaching the structural requirements to support the pool.  I would strongly recommend that you have a Structural Engineer verify your plans.

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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