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tempest 05-01-2009 03:35 AM

Advice needed for reinforcing floor for large Aquarium
5 Attachment(s)
hey all.

I am looking at putting a bigger fish tank in my house but am a little concerned about the weight i would be putting on the floor. I have attached a rough layout of the room, sorry if it is confusing, I don't have any good drawing programs but paint... the floor boards are all blue gum, I don't know what the joists and bearers are short of saying they are hard wood of some type.
I have also attached some pics of the house. The tank in the photo is a 5x2x2, total being about 550Litre system. the new one I'm getting is a 6x6x28"high, all up will be about 1000L system. I'm not even sure I should have the smaller tank there now without reinforcing, I'm sure I'm going way over what the floor was designed to carry with the new setup. How major and what sort of reinforcing needs to be done to carry this load safely?

concrete posts 8.5" square
joists 2x5 18" centre-centre apart
Beams 5x3 90" apart
house is about 50" off the ground

locknut 05-01-2009 04:51 AM

I'm not a structral engineer,
but it seems that there's plenty of room under the questioned area to add two or more posts, say using 4X4 or 6X6 (or your comparable sizes). Of course, they would be pressure treated. You could embed them in concrete boxes and bolt them to the joists. This basically is how I anchored my backyard deck.

glennjanie 05-01-2009 09:27 PM

Welcome Tempest:
The drawing shows that you will be running the tank across several floor joists. It should not stand on 4 feet (at the corners) but have the weight evenly distributed across the joists. If your stand is not designed to evenly distribute the weight, you could use a 4 X 4 runner at the front and back that would reach to a post on each end.

tempest 05-01-2009 10:42 PM

thanks. i was going to run a rectangular base on the stand much the same as in the photo's above, not run it just on the 6 or 8 feet the stand has.
Running a few support posts under the floor concreted into the ground is the best option here? i was thinking of running some angle iron along the joists as well to add extra support, that would be over kill?

BooUrns 05-25-2009 12:40 AM

If I'm reading your description correctly, you have a 2x6 (1.5"x5.5") joist floor and are planning a 1000litre tank on it.

I would not recommend this unless you have direct support under the joists in the form of two 2x10 beams supported by short teleposts on a 8" deep 36"x36" concrete pads.

I did a rough calculation of the weight of your proposed setup:

(I work in gallons but a 1000L tank is equivalent to around 250-265G).
8.3lbs/gallon +2.7lbs/gallon rock, substrate and sump +motor = 11lbs x 265G = 2915 lbs
Add in the weight of the tank and stand and you're already over 3000lbs.

Some houses were just not meant for monster fish keepers... I don't recommend anyone go over 90 gallons in a wood frame house if not close to a bearing wall or structural support.

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