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Building Homes or Extensions/tri level duplex condo, floor weight capacity


QUESTION: please take a look at my floor plan and tell me if i can actually put a B.C. glass tank with stand and canopy. without it going through the floor.

I'm guessing it will be in the neighborhood of 2500-3500 lbs.

i live on the duplex unit. and the fish tank is going on the 2nd floor (of the tri- level duplex condo). its going against two walls. the opposite wall is a set of stairs thats going up to the third level. and another wall that has a storage pantry behind it.

here are pictures of the plan. i highlighted the area where i want to put the tank. i also noticed on the plan that there are metal beams.

ANSWER: Hi Sean, the structure looks capable of holding the weight.  What you don't tell me is the footprint of the tank, how the frame sits on the floor ( does the entire base have contact? Or are there feet or legs? How much of the base in square inches comes in contact with the floor system?) this information is essential in determining any concentrated loads and where they might be located in relation to the floor,joists.  You didn't mention the actual water capacity of the tank in gallons.  There are ways of reinforcing the floor if necessary but it may not be.  Send me some more info and we can continue this conversation..sincerely Bruce Johnson

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

QUESTION: hi Bruce,

thank you for the quick response! the tank is 72" long x 30" deep x 24" high (about 225 gallons) . it is made out of low iron glass (weighs about 400 lbs). and it will be sitting on a 72 long x 30 deep by 30" high pine stand. I am not sure about the weight. but I am told that it has a flat base. there are no legs. it looks something like the link below.

so im guessing the total weight is in the neighborhood of 3000lbs give or take. that's including tank+stand+water+rock.

is the floor structure strong enough to hold that kind of weight? or will I need to reinforce it? if so, how would you recommend in reinforcing it?

here are some pictures of the  area where the tank will be sitting.

sorry for the questions, I just don't want my tank ending down in the garage.

thank you so much for your time!

Sean jin

btw, does the structure of my home contain metal beams? i noticed on the floor plan that it has psl beams. or are just standard wood beams?

thanks again!

Hi again Sean, it's hard to tell from your photos what the actual span of the joists are.  I looked up your 230 joists and they are capable of total loads 158-190 pounds if within an 8-10 foot span.    Your aquarium totals 142 pounds per square foot if distributed evenly over the base.  So it looks pretty good that the joists themselves can handle the weight.  How well your home is built and what types of connectors were used in the framing could be a contributing factor to the overall support system.  I'm saying yes, the floor system is capable of supporting this weight, however, I am not a PE.  You might want to run the numbers by a structural engineer as well. Sincerely Bruce johnson

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Bruce E. Johnson


I can answer any construction related question in regards to carpentry, concrete, drywall, masonry, structural elements of any type of building, residential or commercial. Interior or exterior.


Custom Commercial and residential buildings. Churches, theaters, schools and auditoriums. Most recently I am working with the Catholic Church on several design build committees. I have a website related to scheduling and project supervision. Although my expertise is more related to multimillion dollar commercial, educational and theatrical projects my generous credentials in residential and remodelling construction make me a viable source of information regarding all forms of building questions.

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