Will my tank crash through the floor?
- Thread starter newfishguy
- Start date
B
bigdogzack
Guest
Squid...did you miss all the discussion about wood "creep"
...put the two people in the cast iron tub full of water (and most tubes only hold about 40 gallons but Ill assume your talking about the really old style ones that are 6' long and about 30" deep) and make them eat, sleep, go potty, have ---, etc without getting out at all for a couple of years and then we'll talk
B
bigdogzack
Guest
Squid...and have you ever tried to break up an old cast iron tub?? try it sometime...why I recommended a structural engineer and I'll now add one that is experianced in aquarium dynamics...it's contractor's that have your line of logic that scare me....comparing a tub to an aquarium is like comparing a hammer made of steel (or fiberglass, or acrylic) to a hammer made of glass ...maybe YOU should "think"...
B
bigdogzack
Guest
The Grog: suggest putting a level on all four edges (tops) of your tank and if the tank is getting at all out of level you'l know the structure supporting it is "settling" and putting stresses on the bonded corners and it's probobly just a matter of time before a leak will develop...
sw65galma
Active Member
Originally Posted by Squidd
Ask your self this...
How much water does your tub hold...?
Is it made out of cast Iron...?
Ever have two people in it...?
Do you have "posts" under it...?
Didn't think so..
Tubs don't hold that much...also it's not a permanent weight. besides the weight of it'self.
Now also don't forget you have to ADD that weight to the total weight the floor is holding with the tank...
So figure this..
Do you ever have a lot of people over?
Now think of everything added...
I had my house built with engineered beams to hold the weight...But then we decided to get a King size water bed, jacuzzi, and 2.5 tons of granite counter tops....
Putting my 300 up stairs would be pushing it...If i didn't have that sutff it would have been ok...and it still would have been ok, but then I would be scared to have like 20 people over..
Ask your self this...
How much water does your tub hold...?
Is it made out of cast Iron...?
Ever have two people in it...?
Do you have "posts" under it...?
Didn't think so..
Tubs don't hold that much...also it's not a permanent weight. besides the weight of it'self.
Now also don't forget you have to ADD that weight to the total weight the floor is holding with the tank...
So figure this..
Do you ever have a lot of people over?
Now think of everything added...
I had my house built with engineered beams to hold the weight...But then we decided to get a King size water bed, jacuzzi, and 2.5 tons of granite counter tops....
Putting my 300 up stairs would be pushing it...If i didn't have that sutff it would have been ok...and it still would have been ok, but then I would be scared to have like 20 people over..
B
bigdogzack
Guest
The main issue is that the support structure for an aquarium must be very, very rigid...aquariums simply aren't designed to absorb (and or flex or settle in kind with) the energy created if its suporting structure flexes and or slowly settles (creeps) as a tub, piano, whirlpool. waterbed, etc. is (e.g. if the frame of a waterbed seperates just slightly the neighbors below won't get a shower)...
mandfishes
Member
I'm not worried but how much would a 29 gal weigh?
B
bigdogzack
Guest
fresh water weighs 8.33 pounds per gallon...I personally use 10 pounds per gallon for salt for the increased density, added weight due to live rock and sand, etc....
squidd
Active Member
Originally Posted by Bigdogzack
Squid...did you miss all the discussion about wood "creep"
...put the two people in the cast iron tub full of water (and most tubes only hold about 40 gallons but Ill assume your talking about the really old style ones that are 6' long and about 30" deep) and make them eat, sleep, go potty, have ---, etc without getting out at all for a couple of years and then we'll talk
Squid...and have you ever tried to break up an old cast iron tub?? try it sometime...why I recommended a structural engineer and I'll now add one that is experianced in aquarium dynamics...it's contractor's that have your line of logic that scare me....comparing a tub to an aquarium is like comparing a hammer made of steel (or fiberglass, or acrylic) to a hammer made of glass ...maybe YOU should "think"...
B.D.Z....Did YOU miss the original question from "newfishguy"...?
IE: Will My Tank Crash Through the Floor...?
The answer is no...and the relationship and comparison between a 70 gallon fishtank and a 300lb tub with 40X8.33=332 lbs water and an adult is actually quite relevent...
Neither needs posts and neither will "crash through the floor"...
Now..You want to talk structural engineering and aquarium dynamics...?
What you so genericly refer to as "wood creep" is actually "strain"...the deformation (streching, compaction, curvature) caused by an external force...
Which is resisted by "stress", internal resistance to an external force...
ALL building materials have an allowable modulus of elasticity (ratio of stress/strain) and deformation can be predicted...
To say that every tank installation needs to "structurally" engineered to "prevent" movement is sheer foolishness if not "impossible" ...
Houses move...floors move...tanks will move... Strain needs to be acknowaleged and delt with...it cannot be prevented...
However the "checking, leveling and monitoring" of said movement (with occasional adjustments) IS sound advise...because there are limits to the allowable strain...
Squid...did you miss all the discussion about wood "creep"
Squid...and have you ever tried to break up an old cast iron tub?? try it sometime...why I recommended a structural engineer and I'll now add one that is experianced in aquarium dynamics...it's contractor's that have your line of logic that scare me....comparing a tub to an aquarium is like comparing a hammer made of steel (or fiberglass, or acrylic) to a hammer made of glass ...maybe YOU should "think"...
B.D.Z....Did YOU miss the original question from "newfishguy"...?
IE: Will My Tank Crash Through the Floor...?
The answer is no...and the relationship and comparison between a 70 gallon fishtank and a 300lb tub with 40X8.33=332 lbs water and an adult is actually quite relevent...
Neither needs posts and neither will "crash through the floor"...
Now..You want to talk structural engineering and aquarium dynamics...?
What you so genericly refer to as "wood creep" is actually "strain"...the deformation (streching, compaction, curvature) caused by an external force...
Which is resisted by "stress", internal resistance to an external force...
ALL building materials have an allowable modulus of elasticity (ratio of stress/strain) and deformation can be predicted...
To say that every tank installation needs to "structurally" engineered to "prevent" movement is sheer foolishness if not "impossible" ...
Houses move...floors move...tanks will move... Strain needs to be acknowaleged and delt with...it cannot be prevented...
However the "checking, leveling and monitoring" of said movement (with occasional adjustments) IS sound advise...because there are limits to the allowable strain...
B
bigdogzack
Guest
Squid: Sorry, but you don't know your physics...I quote from the Merriam-Webster Collegiate Unabridged Dictionary: "Creep: 5 a : to slip or gradually shift position b : to change shape permanently from prolonged stress..." ...structural failure is NOT "crashing thru the floor' but rather an assemply or system (e.g. walls, roofs, floors, doors, windows, etc.) performing in a way that does not meet the intent of design and or the expectations of the client/occupant (e.g. cracks in walls, door not closing properly from header sag, etc.)...yes, all buildings do have basic assumed expectaions that they are designed to but several thousand pound tank systems are NOT inclusive in those assumptions... I did not say that ALL tanks need a structural engineer's input, but will state that if a homeowner does not have the knowledge base to make informed decesions about tank placement and or support they SHOULD talk to a structural engineer (not a contractor, unless that contractor hase experience woth structural dynamics) OR, in lieu of actual structural design calculations, over design such that the tank remaining static is assurred.. .now to imply that a tank is similar to typical houshold furniture...sorry, but that's "foolishness"...yes, deformation CAN be predicted and you CAN design such that NO deformation will occur (every action has a reaction, as long as the available reaction exceeds the action, no deformation will occur)...e.g. steel will not creep over time as concrete or wood will....finally, again, a tub which has short term loading is not a very good anology to what is occuring with the long term loading a tank induces...
squidd
Active Member
Squid: Sorry, but you don't know your physics...I quote from the Merriam-Webster Collegiate Unabridged Dictionary:Creep: 5.a.
Okie Dokie...if you say so...
Keep looking... once you get past the "C"s you only have to go as far as the 1st def.s... :yes:
And come on, are you sure short term loading, (tubs, Live loads, Snow loads, ten people in front of Guy's tank) aren't applicable to long term deflection..??
Keep looking... once you get past the "C"s you only have to go as far as the 1st def.s... :yes:
And come on, are you sure short term loading, (tubs, Live loads, Snow loads, ten people in front of Guy's tank) aren't applicable to long term deflection..??
B
bigdogzack
Guest
And come on, are you sure short term loading, (tubs, Live loads, Snow loads, ten people in front of Guy's tank) aren't applicable to long term deflection..??
Well, let's quantify...the tank is probably more likely to absorb some sort term deflection more redily than longterm deformation of its support structure...e.g. Roof trusses are designed for a long term dead and live load (in MN the live load is 40# / sf) but they also will have a short term (7 day) live load rating which is basically established for the weight involved when the shingles (on pallets on a larger structure) are temporarily stacked for before installation...if you leave the stacked shingles in place for to long of a time you may affect the integrity of the trusses...an anology, pick up a couple hundred pounds and just stand there, do your shoulders start to sag after a while even though you had no problems at first, same thing happens to any wood strucure if the load exceeds its ability to resist the strain, it might just deflect at first, but if the load is to great it'll start to creep (sag) and in the proccess of transferring the energy or strain your tank may develope a leak just as your legs, wrists, etc. start to ache (if the load is simply way to much to begin with it may "crash thru the floor" just as you may tear a muscle, tendon, even possibly break a bone, etc.)
And yes, I did get by the ccccc's but my point is that creep occurs because the STRAIN of a long term concentrated point load wasn't factored into the design calculations...e.g. residential floor systems are designed to a uniform 40 #/sf live load and a concentrated point load of 300#...it reguires a much smaller beam to handle a 1,000 #/lf uniform load over a span of say 10' than for a 10,000 # concentrated point load occuring at the middle of the span...
Well, let's quantify...the tank is probably more likely to absorb some sort term deflection more redily than longterm deformation of its support structure...e.g. Roof trusses are designed for a long term dead and live load (in MN the live load is 40# / sf) but they also will have a short term (7 day) live load rating which is basically established for the weight involved when the shingles (on pallets on a larger structure) are temporarily stacked for before installation...if you leave the stacked shingles in place for to long of a time you may affect the integrity of the trusses...an anology, pick up a couple hundred pounds and just stand there, do your shoulders start to sag after a while even though you had no problems at first, same thing happens to any wood strucure if the load exceeds its ability to resist the strain, it might just deflect at first, but if the load is to great it'll start to creep (sag) and in the proccess of transferring the energy or strain your tank may develope a leak just as your legs, wrists, etc. start to ache (if the load is simply way to much to begin with it may "crash thru the floor" just as you may tear a muscle, tendon, even possibly break a bone, etc.)
And yes, I did get by the ccccc's but my point is that creep occurs because the STRAIN of a long term concentrated point load wasn't factored into the design calculations...e.g. residential floor systems are designed to a uniform 40 #/sf live load and a concentrated point load of 300#...it reguires a much smaller beam to handle a 1,000 #/lf uniform load over a span of say 10' than for a 10,000 # concentrated point load occuring at the middle of the span...
zman1
Active Member
See this post for some interesting information
https://www.saltwaterfish.com/vb/showthread.php?t=173182
https://www.saltwaterfish.com/vb/showthread.php?t=173182