Floor Support Dilemma: Seeking Guidance from Experienced Hobbyists

Reef5 · Mar 19, 2024

I've searched and found similar questions regarding whether the floor will support my tank, and the answer seems to be to either add support or hire a structural engineer for peace of mind.

For those who have been in a similar situation, did you hire a structural engineer first and then bring in a contractor, or did you skip the engineer and hire someone (or do it yourself)?

To provide context, I recently received a Prostar 230. Even without water, the tank and stand weigh approximately 740 pounds. I plan to position the tank perpendicular to the floor in a corner against an outside wall (old house). While adding support doesn't seem overly complex, as I've found helpful YouTube videos, navigating the crawlspace below poses a particular challenge for me (I have a slight degree of claustrophobia).

I would greatly appreciate any advice you could offer on hiring a contractor (like the type of contractor to call for quotes) or any other guidance based on your experiences with similar situations. Thank you.

Rjukan · Mar 19, 2024

Perpendicular to the wall? Or parallel with the wall. Of course you want to run the tank across the floor joists, not along them if at all possible. If you're setting up the tank against the outer wall, that's the best case scenario.
Can you navigate the crawl space enough to take a few pics to post here? Along with the space you're looking to put the tank in? That will help with recommendations. Usually a general contractor would be able to help you with this type of reinforcement, and a structural engineer wouldn't be needed.

Reef5 · Mar 19, 2024

Hello Rjukan,

Yes, describing it as 'across the floor joists' is more accurate.

I took some photos of the crawlspace. The tank will be situated in the far corner. The yellow thing is insulation foam, just in case.

Thank you.

ca1ore · Apr 16, 2024

The one thing that folks seem not to consider is floor flex - in other words, how far the joists will deflect under the load. 750 pounds doesn't seem like all that much, so odds are your joists aren't going to fracture, but they will likely deflect, at least a bit. Since you have easy access, I would definitely put in a couple of jack posts to eliminate any deflection or floor bounce. Cannot speak to the claustrophobia thing. If it's an old house, and the floor is still solid, the odds of it collapsing while you are under there is vanishingly small. You probably have a higher chance of getting hit by a car retrieving your mail.