Opinions on floor support 240 gallon

ReefHunter006

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Hi all,
Planning on installing a 240 gallon aquarium. The below is a lay out of the room the tank will go in.

i believe the joists run about 12 ft.
picture of the joist.
DAD782FF-E893-4D31-80A6-FDE1535452B2.jpeg

Apologies for the crude picture. Should I throw some pier blocks with supports in the basement? Or other suggestions for supporting the tank

Let me know what other info Might be needed.

36C6E217-0DF7-4A11-906F-9D0AE85DBA1E.jpeg
 
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flourishofmediocrity

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I could not get a structural engineer to come to my house to tell me if I needed to reinforce my floor for a 200 gallon peninsula spanning a few joists. They all said the job was too small. I ended up just paying a couple of guys I hired online to come pour some concrete pads and reinforce the area with a couple of two by eights held up with a couple of four by fours. I wish I could tell you how well it worked out, but the tank is still sitting in the garage waiting for the sump stand to be built and the sump to arrive.
 

redfishbluefish

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I've been out of the business for years, but 2x6 joists would only be used for relatively short spans. I don't have the residential code any more, but I'd bet 12 foot span is way too long for 2x6's. I'd personally put in beams perpendicular to the joists below the tank with supporting posts, ideally with footings.
 
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ReefHunter006

ReefHunter006

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I've been out of the business for years, but 2x6 joists would only be used for relatively short spans. I don't have the residential code any more, but I'd bet 12 foot span is way too long for 2x6's. I'd personally put in beams perpendicular to the joists below the tank with supporting posts, ideally with footings.
I agree, I move in next week. I feel the there must be a supporting basement wall that cuts that span in half somewhere. That or it’s a 2x8, but even that still feels like but of a stretch. When I move in next week I’ll be able to get much better idea what that span really looks like.
 
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kalare

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2x8 even... Still too small for a 12 foot span. Needs reinforcement. Depending on your head space, the suggestion of beams and posts sounds the easiest.
 

Beau_B

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That construction looks to be 1920s +/- and proper 2” stock. Whether 6” or 8” doesn’t matter. Additional support should be installed under the front edge of the aquarium location. What is the floor in the unfinished space? If dirt and a crawl space, the most cost effective and diy friendly method would be to form a concrete footer and then add vertical members for each joist (2x4 is sufficient). Essentially create a support wall. Depending on conditions, it may be possible to forgo the concrete footer and simply use ground contact lumber (pressure treated)
 
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ReefHunter006

ReefHunter006

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That construction looks to be 1920s +/- and proper 2” stock. Whether 6” or 8” doesn’t matter. Additional support should be installed under the front edge of the aquarium location. What is the floor in the unfinished space? If dirt and a crawl space, the most cost effective and diy friendly method would be to form a concrete footer and then add vertical members for each joist (2x4 is sufficient). Essentially create a support wall. Depending on conditions, it may be possible to forgo the concrete footer and simply use ground contact lumber (pressure treated)
Excellent eye. House was built 1923.

The floor under that is a concrete basement floor.

A couple questions.

If I add a vertical 2x4 to each joist directly under the aquarium, that would cut off most of the basement from access as well as the water heater. Does it have to be each joist?

Would running something like a 4x4, spanning the aquarium, being supporting by two pier blocks or screw jacks and 4x4 posts on each side provide the necessary support without limiting access?

How worried do I need to be about lining up the support directly under the aquarium? A foot going to make a large difference?

thanks for the reply.
 

Beau_B

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Excellent eye. House was built 1923.

The floor under that is a concrete basement floor.

A couple questions.

If I add a vertical 2x4 to each joist directly under the aquarium, that would cut off most of the basement from access as well as the water heater. Does it have to be each joist?

Would running something like a 4x4, spanning the aquarium, being supporting by two pier blocks or screw jacks and 4x4 posts on each side provide the necessary support without limiting access?

How worried do I need to be about lining up the support directly under the aquarium? A foot going to make a large difference?

thanks for the reply.

If you want to keep access, then you are going to want a header with end posts, yes. A 4x4 would be a poor choice. In 8ft, double up a 2x8 #2 and use a couple jack posts (ease). Depending on the thickness of the slab, it may be best to put pads under the posts so they don't crater (concrete pads, 12x12 ply lam). Couple hundo and bing bang boom. It's not a giant load, and it is still spread out through the floor system but does need protection against deflection... and no one likes seeing the tank shake. Easy to remove when you're done.

Edit: the exact location under the tank isn't crutial, but ideally, yes, under the front edge of the cabinet so that it is stacked. The further away the more you invite deflection.
 
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ReefHunter006

ReefHunter006

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If you want to keep access, then you are going to want a header with end posts, yes. A 4x4 would be a poor choice. In 8ft, double up a 2x8 #2 and use a couple jack posts (ease). Depending on the thickness of the slab, it may be best to put pads under the posts so they don't crater (concrete pads, 12x12 ply lam). Couple hundo and bing bang boom. It's not a giant load, and it is still spread out through the floor system but does need protection against deflection... and no one likes seeing the tank shake. Easy to remove when you're done.

Edit: the exact location under the tank isn't crutial, but ideally, yes, under the front edge of the cabinet so that it is stacked. The further away the more you invite deflection.
What
If you want to keep access, then you are going to want a header with end posts, yes. A 4x4 would be a poor choice. In 8ft, double up a 2x8 #2 and use a couple jack posts (ease). Depending on the thickness of the slab, it may be best to put pads under the posts so they don't crater (concrete pads, 12x12 ply lam). Couple hundo and bing bang boom. It's not a giant load, and it is still spread out through the floor system but does need protection against deflection... and no one likes seeing the tank shake. Easy to remove when you're done.

Edit: the exact location under the tank isn't crutial, but ideally, yes, under the front edge of the cabinet so that it is stacked. The further away the more you invite deflection.
Thank you!

What would you do to help minimize deflection? A second brace a few feet away?
 

Beau_B

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Bigger wood, less deflection! A steel beam? Haha.

Having a substantial carry under the tank that is properly supported will eliminate the deflection.
 
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Beau_B

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I wouldn't bother, you're not trying to help the whole floor, just where the tank is. Also sistering old joist sounds easy and fun, but it isn't. Probably mechanicals (electrical at least) in them and they're unlikely to be level and true. Getting it all done up is a chore. Focus on stopping what's there from moving by reducing span, direct support to ground.
 
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ReefHunter006

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I wouldn't bother, you're not trying to help the whole floor, just where the tank is. Also sistering old joist sounds easy and fun, but it isn't. Probably mechanicals (electrical at least) in them and they're unlikely to be level and true. Getting it all done up is a chore. Focus on stopping what's there from moving by reducing span, direct support to ground.
Thanks really appreciate the input.
 
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