Expert: Bruce E. Johnson - 1/5/2010

Question
Hi Bruce,

I had a friend of mine who is a general contractor install an electric hot water heater for me. Since it's in a 2nd floor condo, we put the water heater in a bedroom closet with a drain pan that would empty into an adjacent bathroom. Because of gravity, he had to build a stand for the water heater. He built a 22" cube width made entirely of 3/4" plywood (screwed together). It is 24" in height. It almost looks like a night table size. My question is how much weight can this hold? It is supporting a 40gal water heater which I estimate is about 420lbs filled. I had concerns about it not having 2x4s instead of plywood sides

Thank you  

Answer
Hi Anthony, If the top panel of the box covers the sides then you should be fine.  This allows the plywood to support itself.  If the top panel of the box is inside the sides then you are relying on the vertical shear of the screws to support the water heater.  Since water distributes weight equally the base of your heater has probably 4 square feet of area which translates down to a little over 100 pounds a square foot which should easily be supported by the box.  Of course the type of plywood, how many screws, what size screws, whether or not the panels were glued together also, may determine how the box holds up over the years but since the water heater is stationary and no further stress is being applied to the structure of the box, personally, I think you are okay..I hope this information helps, please feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com