Construction Industry/Gun safe on wood floor


The floor is 2x8 joists at 16" O.C. spanning 11'-4". The support beam is 8" deep, 4" flanges. The steel columns supporting the beam are at 10'-0" on center. The (2) joists that will directly take the weight of the safe come down nearly in the middle of a column span. House was built in 1948. One floor home with basement. The flooring appears to be 3/4" planks. There is an original hardwood floor over that.

The safe will weigh 1,300 lbs empty and has a 25"x31" foot print. The 31" length will be up against a wall that has a stair well on the other side. The left side of the safe will be against an end foundation wall of cmu block that the joists end at and rest on.
The joists and stair well run parallel to the 31" width of the safe.

I was planning at minimum to add a third 2x8 to the double 2x8 stair well framing, screwing and gluing all three together. The next joist cant be double up because electrical conduit is in the way. This one currently has solid blocking to the stair well. In the next space between joists I'll add a new double 2x8 and then double up the next two joists. Solid blocking to all of them and using joists hangers and/or ledger at the cmu wall for the new joist members.

I suspect this would not be enough and can add a 2x4 wall nearly  under the end of the 31" width of the safe. The wall could also be built with end posts/anchors plywood and screw spacing attachment to the solid blocking to act as a shear wall to add lateral stability due to the stairwell location.

Would this work or is it a lost cause due to the weight of the safe?

Thank you.

Hello Mark,

Your assumption is correct.  The only safe way to support your gun safe is to install columns under the four corners of the safe.  Your safe has a dead load weight of approx. 260 lbs per square foot.  This exceeds the structure limits of your floor.  Adding floor joist as beams will help solve the problem but the cost is excessive compared to adding columns.

I hope this was helpful

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Roger Zona


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.


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.

Previously - NAHA Currently - FLCA (Florida Licensed Contractors Assoc.)

Palm Beach Post newspaper - weekly Q & A column Happy Herald monthly real estate publication - monthly column

Michigan State University University of Detroit BS in Engineering

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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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