Will my aquarium fall through the floor?

[ReefDreamz]

Any engineers in the house? Trying to determine if my plan for reinforcing my 1st floor tank location will be sufficient or not. I'm located in New Hampshire.


Numbers:

Tank is 49.9" long×29.5" deep×23.6" high. Model is REEF LX 190.4 https://waterboxaquariums.com/pages/technical-specifications#reeflx

Tank with stand is 49.9" long×29.5" deep×63" high. Stand covers a 10.22 ft² area on the floor.

Dry weight of tank and stand is 890 lbs.

Total water volume of system is 190 gallons equalling 1634 lbs.

Estimated total weight of system is around 2700 lbs including a conservative 175 lbs of equipment and aquarium decor.

Estimated pounds per ft²: 264


Structural:

Intended tank location is roughly here:

Tank will run parallel with joists unfortunately and not against a load bearing wall. The back of the tank will sit roughly 3 to 6" away from the left most (double) joist in the image. The front of the tank will sit roughly 2" in front of the right most joist. So it will be sitting on 2 joists but only just ~2" over the right most joist The joist length from the foundation wall to the end of the tank is 40". The joist length from the center beam to the end of the tank is 59".

The joists are 12' 5" long 16" on center, but the distance from the left most joist to the center joist is a little less, ~14". The joists are 2x10 (actual dimensions 1.5"x9").


The Plan:

Run 2 ~30" long PT 4x4's perpendicular to the joists spanning the three joists in question located approximately 10" in from each edge of the tank. Attach one adjustable jack post to each 4x4 directly under the center joist. Attach the other end of each jack post to the center of an ~18" long PT 6x6. The 6x6 will be sitting on the basement slab.

 

[LiveFreeAndReef]

Is there a better spot to put the tank? Seems like a lot of work to keep it in that spot!

 

[LeftyReefer]

If nothing else, just install a jack post under the joist(s) in question and call it good.

 

[ZoWhat]

Get one of these installed and let your mind relax

Adjustable Jack Post - avail at Homedepot and Lowes. Roughly $75 to $100

.

 

[SPS2020]

Look in my build thread for an article in post #16 that specifically addresses your question.

 

[davidcalgary29]

Time to call in that residential architect! That cross joist is really bothering me -- it's cut up into segments -- which seems to be trouble in the making.

 

[ReefDreamz]

Time to call in that residential architect! That cross joist is really bothering me -- it's cut up into segments -- which seems to be trouble in the making.

That's how it's supposed to be. That's not a cross joist its called blocking. The blocking provides lateral strength.

 

[ZoWhat]

Time to call in that residential architect!

....which he'll write up a wonderful $1500 -$2000 quote

See my post above using an Adjustable Jack Post.

Anchor the Jack Post to a 4x6 wood beam perpendicular to the joists.... then drink a beer and relax.

Once a year check the torque tension on the Jack Post so to prove it hasn't loosened. Houses shift weight all the time based on foundation

DIY job = $200
Structural Engineer = $2000
.

 

[ReefDreamz]

Look in my build thread for an article in post #16 that specifically addresses your question.

Thanks! I've read that article multiple times. Unfortunately, it is more cautionary than how to. The only real conclusion given is to consult a structural engineer. I'm hoping to try and avoid months of waiting for an appointment with a structural engineer and hundreds of dollars for them to tell me to do what I already am planning to do.

 

[ReefDreamz]

....which he'll write up a wonderful $1500 -$2000 quote

See my post above using an Adjustable Jack Post.

Anchor the Jack Post to a 4x6 wood beam perpendicular to the joists.... then drink a beer and relax

DIY job = $200
Structural Engineer = $2000
.

What about where the jack post attaches to the floor though? My basement floor is just a concrete slab. I was planning to attach the floor side of the jack post to a 6x6 laying on the slab. I don't want to crack my slab but I don't want to open the slab and pour footers either.

 

[ZoWhat]

What about where the jack post attaches to the floor though? My basement floor is just a concrete slab. I was planning to attach the floor side of the jack post to a 6x6 laying on the slab. I don't want to crack my slab but I don't want to open the slab and pour footers either.

Say roughly 2000lbs get directly transferred thru the post onto the concrete slab (which is unlikely) .... that amount of weight IMO would crack a concrete slab.

Think of your garage floor with a 4000lb vehicle moving in and out daily. It shouldnt crack bc of a 4000lb car.

It's hot and cold and moisture that puts crack in concrete. Rarely weigh does that... and it would have to be tens of thousands of lbs.


.

 

[piranhaman00]

Get one of these installed and let your mind relax

Adjustable Jack Post - avail at Homedepot and Lowes. Roughly $75 to $100

.

When you use one of these, how much pressure should be applied ? Just snug with the joist?

 

[ReefDreamz]

Say roughly 2000lbs get directly transferred thru the post onto the concrete slab (which is unlikely) .... that amount of weight IMO would crack a concrete slab.

Think of your garage floor with a 4000lb vehicle moving in and out daily. It shouldnt crack bc of a 4000lb car.

It's hot and cold and moisture that puts crack in concrete. Rarely weigh does that... and it would have to be tens of thousands of lbs.


.

So then why do they pour footers for permanent load bearing jack posts in basements? Why not just put them on the slab with no footer?

 

[ZoWhat]

When you use one of these, how much pressure should be applied ? Just snug with the joist?

I'm sure that an answer on Google. you wouldn't want so much torque that it shifts those joists into a high point

Imo sug is too loose. Tight is better. But not so tight you hear wood cracking above

 

[ZoWhat]

So then why do they pour footers for permanent load bearing jack posts in basements? Why not just put them on the slab with no footer?

You're talking the weight of a house vs a 2000lb tank

 

[Bad Company]

Safest is to get a structural engineer.
However, assuming that the pad is properly poured on the substrate, and there are no voids under the slab, the odds of it cracking are very low, although not 0.

I would not install a tank without reinforcing the floor. The tank is only supported by two joists, and it is far from a another supporting structure. I would install an adjustable jack post as suggested above by zoa what. Use level on your floor to ensure that the jackpost doesn't change the lay of the floor when torqued, and use a 4X6 at the top perpendicular to the joists to spread the support over 4 joists (including that doubler).

Source: I am a Mechanical Engineer, and have poured concrete flatwork.

 

[LeftyReefer]

If you are really worried about the concrete floor, you could also put down a steel plate, under the jack post.... to spread the load out to more of the concrete.

 

[ReefDreamz]

Safest is to get a structural engineer.
However, assuming that the pad is properly poured on the substrate, and there are no voids under the slab, the odds of it cracking are very low, although not 0.

I would not install a tank without reinforcing the floor. The tank is only supported by two joists, and it is far from a another supporting structure. I would install an adjustable jack post as suggested above by zoa what. Use level on your floor to ensure that the jackpost doesn't change the lay of the floor when torqued, and use a 4X6 at the top perpendicular to the joists to spread the support over 4 joists (including that doubler).

Source: I am a Mechanical Engineer, and have poured concrete flatwork.

Thank you! I plan to install two or three 4x6's running perpendicular to the joists under the tank. Each 4x6 will be attached to a jack post and the floor side of the jack post will be attached to a 4x6 or 6x6 sitting on the slab. The 6x6 on the slab will extend out past where it contacts the jack post at least 9" to help spread the weight.

 

[ReefDreamz]

Safest is to get a structural engineer.
However, assuming that the pad is properly poured on the substrate, and there are no voids under the slab, the odds of it cracking are very low, although not 0.

I would not install a tank without reinforcing the floor. The tank is only supported by two joists, and it is far from a another supporting structure. I would install an adjustable jack post as suggested above by zoa what. Use level on your floor to ensure that the jackpost doesn't change the lay of the floor when torqued, and use a 4X6 at the top perpendicular to the joists to spread the support over 4 joists (including that doubler).

Source: I am a Mechanical Engineer, and have poured concrete flatwork.

Also, I was planning to span only the 3 joists under the tank with the 4x6's (the double and the next 2) and place the jack posts directly under the center joist. If I was to span 4 joists instead of 3 where would you recommend locating the jack posts?

 

[KrisReef]

You would be fine without any jacks or additional support if you weren’t in New Hampshire. In this instance the tank will absolutely fall through the floor especially since you are in that state.

If you don’t believe me ask an engineer but I’m sure they will back me up.

Modern wooden subfloors routinely fail in the State of NH.