Expert: jonewall - 2/28/2010

Question
I just bought a 180 gallon fish tank and the only place i am able to put it is parallel to the joist they are 2x10 it is next to the stair well so the first joist is doubled and the out side joist it sits on i doubled should i double the middle on also they are 14 foot span and the tank sits at the edge of a 4 ply 2x8 header

Answer
 Adam

I really in all fairness can't give you an exact answer although here is some info

calculate the size of the bearing area  example  2' x 4'   8 square feet

the weight of the tank filled with water   180x the weight of 1 gallon

now divide the numbers to calculate the weight per square foot  example  20lbs /sf

the span of the joist will carry an amount of weight and the size   2x 10

Suggest you can make a sketch, locate where the tank will set on the joist etc # important be

alert to where bearing walls are #if there are bearing wall on the area you will need to

consider  the extra weight.

Talk to a  lumber yard tech  They usually can help if you explain the situation  
to your success
jon e