Go Back   Aquarium Advice - Aquarium Forum Community > General Aquarium Forums > General Hardware/Equipment Discussion
Click Here to Login

Join Aquarium Advice Today
Reply
 
Thread Tools Search this Thread Display Modes
Please support our sponsors and let them know you heard about them on AquariumAdvice.com
 
Old 04-27-2010, 02:40 AM   #21
Aquarium Advice Activist
 
Join Date: Nov 2009
Location: Memphis, TN
Posts: 176
Jcarlilesiu,

I reread my post, and I didn't explain myself properly. I was referring to exceeding a load limit by lets say 50%, over a 1 square foot area, VS 25% over a 10 square foot area, for a given room size. You said there's no mandated safety margin, so that answers my question. The reason I asked, is because there is something similar with aircraft. I know this entire post doesn't really relate to the topic, I just wanted you to see where I was coming from.

I'm not an engineer, but I do know my way around an airplane. In aircraft design limits, aircraft have to be certified for a certain load factor (G force), depending on the category the airplane will be operated in. There is also a set safety margin the airplane must meet. Generally, it's 1.5 times the load limit for that particular category. For example, a normal category airplane needs to be able to maintain structural integrity up to 3.8 G's, and at it's maximum certified weight. To be certified for 3.8 however, it must actually withstand 5.7 before failing. That margin of safety is basically meant to allow for unforeseen circumstances, like an in flight emergency or unnoticed structural problem.

The other trick is that many normal category airplanes can actually be operated in the utility category provided certain conditions are met. The utility category gives G limits up to 4.4, and also increases the safety margin to 6.6 G's. The trade off is a given airplane will have a lower certified weight for the utility category. Basically, you're putting a more concentrated load on parts of the airplane by maneuvering harder, but you compensated by lowering the overall weight of the plane.
__________________

__________________
jestes is offline   Reply With Quote
Old 04-28-2010, 06:13 PM   #22
Aquarium Advice Addict
 
Join Date: Aug 2005
Location: Chicago
Posts: 1,020
Send a message via Yahoo to jcarlilesiu
Quote:
Originally Posted by jestes View Post
Jcarlilesiu,

I reread my post, and I didn't explain myself properly. I was referring to exceeding a load limit by lets say 50%, over a 1 square foot area, VS 25% over a 10 square foot area, for a given room size. You said there's no mandated safety margin, so that answers my question. The reason I asked, is because there is something similar with aircraft. I know this entire post doesn't really relate to the topic, I just wanted you to see where I was coming from.

I'm not an engineer, but I do know my way around an airplane. In aircraft design limits, aircraft have to be certified for a certain load factor (G force), depending on the category the airplane will be operated in. There is also a set safety margin the airplane must meet. Generally, it's 1.5 times the load limit for that particular category. For example, a normal category airplane needs to be able to maintain structural integrity up to 3.8 G's, and at it's maximum certified weight. To be certified for 3.8 however, it must actually withstand 5.7 before failing. That margin of safety is basically meant to allow for unforeseen circumstances, like an in flight emergency or unnoticed structural problem.

The other trick is that many normal category airplanes can actually be operated in the utility category provided certain conditions are met. The utility category gives G limits up to 4.4, and also increases the safety margin to 6.6 G's. The trade off is a given airplane will have a lower certified weight for the utility category. Basically, you're putting a more concentrated load on parts of the airplane by maneuvering harder, but you compensated by lowering the overall weight of the plane.

I understand what you are saying but I would have a hard time comparing structural integrity of a building similar to that of an airplane which discusing exceeding design limits. The types of design methodology are so different, as well as the types of forces which impact the design.

Building focus basically on two types of loads. Dead loads, which is the members of the building themselves, and live loads, everything else. Live loads can be things that can move around like people and furniture, to other things like wind.

I would not recommend anybody exceed the intended live load of their building because of a percieved safety factor. I think that is just asking for trouble.

The only point I am trying to make here is that I think people have somewhat of a mis-conception about the limits of buildings. People know not to take a car at 120 mph around a hairpin turn, and they know they can't jump and down on things without breaking them. Those simple principles hold true to buildings as well. I have come across many people who think that they would be fine if they parked their car in their living room.

Fact is, buildings, like anything else, have limits as well. We design those buildings for worst case scenarios, but we can't foresee or financially afford to make them bullet proof. Trade Centers case and point.

Buildings have limits, and some of the aquariums being bought and built out there are pushing the limits of that design. When buildings collapse, and people get hurt, it makes the news since its so rare. I am just trying to make everybody aware that buildings aren't invinsible.

I am happy to help consult anybody who may have concerns.

Jake
__________________

jcarlilesiu is offline   Reply With Quote
Old 04-28-2010, 11:59 PM   #23
Aquarium Advice Addict
 
Join Date: Apr 2010
Location: BC, Canada
Posts: 2,398
That article was AWESOME! But I can tell some people didn't read it :-p so here it is again
http://www.african-cichlid.com/Structure.htm
__________________
Sometimes life is best left to it's own devices.
If your not happy at what you're looking at, you're looking at it the wrong way.
My 320g tank build in progress watch at ---> http://www.aquariumadvice.com/forums/f71/320g-build-journey-experiment-128784.html
Greenmaster is offline   Reply With Quote
Old 04-29-2010, 03:02 AM   #24
Aquarium Advice Addict
 
Join Date: Aug 2005
Location: Chicago
Posts: 1,020
Send a message via Yahoo to jcarlilesiu
I agree that the article is well written and does a good job of explaining basic principles of structural engineering and how aquariums relate. I don't however agree with everything said.

The idea that you can count on safety factors designed into the floor framing to base the size of aquarium suitable for an area is dangerous. Point loads like an aquarium are tricky.

Theoretically, based on the article, the author makes it sound like you can take the gross design load in any room and concentrate it under the aquarium safely. In a very large framed area with 40-60 pounds PSF, that could represent a lot of weight. Consentrating that weight under a small footprint of an aquarium is spelling disaster safety factor or not.

My point here is not to argue but to offer up advice to anyone that needs it. I am an Architect and have been designing residential buildings for some time. I think the author did a good job, better than I am doing posting on my blackberry, and I think everybody should read it to. Just don't take it as gospel.

Jake
jcarlilesiu is offline   Reply With Quote
Old 04-29-2010, 03:15 AM   #25
Aquarium Advice Addict
 
CA_BroncoFan's Avatar
 
Join Date: Jan 2010
Location: Sacramento Area
Posts: 1,553
Quote:
Originally Posted by Etunes View Post
Wow, amazing info. This is exactly what i was looking for. But this would not apply with a 1 story house with a foundation would it?

Here is a side question, how would you go about WERE to reinforce the floor if it needed it?
no not usually as they mostly have concrete foundations (the ones without basements of course). Its what i have in CA.

There are plenty of ways to reenforce the floors, the article posted in this thread gives way to ideas.
__________________
-CHAD
"Another Fish Tank!?!?!?!?" -My Wife
CA_BroncoFan is offline   Reply With Quote
Old 04-29-2010, 03:18 AM   #26
Aquarium Advice Addict
 
Join Date: Apr 2010
Location: BC, Canada
Posts: 2,398
He actually states that that isn't the case... he says that you should really asses the situation every time and that at 55g and smaller no mater the footprint you can put it anywhere in almost any room... over that size you need to really pay attention to what is under the sub-floor. Also you are best to place it near a load barring wall perpendicular to the floor joists. He also states a lot more so it is really worth reading more then once if you are trying to figure out if a tank can go in a specific location. He also gives good tips on adding support. He doesn't say to count in safety factors he is just informing you that they are there and that they can be mitigated by a flaw in the wood like a knot or a split.
__________________
Sometimes life is best left to it's own devices.
If your not happy at what you're looking at, you're looking at it the wrong way.
My 320g tank build in progress watch at ---> http://www.aquariumadvice.com/forums/f71/320g-build-journey-experiment-128784.html
Greenmaster is offline   Reply With Quote
Old 04-29-2010, 05:27 PM   #27
Aquarium Advice Addict
 
Join Date: Aug 2005
Location: Chicago
Posts: 1,020
Send a message via Yahoo to jcarlilesiu
Quote:
Originally Posted by Greenmaster View Post
He actually states that that isn't the case... he says that you should really asses the situation every time and that at 55g and smaller no mater the footprint you can put it anywhere in almost any room... over that size you need to really pay attention to what is under the sub-floor. Also you are best to place it near a load barring wall perpendicular to the floor joists. He also states a lot more so it is really worth reading more then once if you are trying to figure out if a tank can go in a specific location. He also gives good tips on adding support. He doesn't say to count in safety factors he is just informing you that they are there and that they can be mitigated by a flaw in the wood like a knot or a split.


Quote:
"According to the building code my house can only support a maximum total load of 40 psf anywhere on the floor."
  • No, the 40 psf is a theoretical uniform design live load over your entire floor. You might have a whole lot more than 40 psf directly under your aquarium, but that's okay because you didn't fill your entire room with aquariums either.
Thats exactly what he is saying here, in the very first response to a myth.



Then, the very next line he says:



Quote:
"So then, if I fill my entire room with aquariums that weigh more than 40 psf, my floor will collapse."
  • No it shouldn't. I said that the 40 psf was a MINIMUM design load and I also said that it is a SAFE load. That means that your floor could be (probably is) stronger than the 40 psf minimum in many places, and it also means that the full safety factor is still there to prevent a collapse.
I don't agree with this line of thinking. If instructions say don't exceed X, even though the engineers designed in some safety factor, then you should exceed X.



I understand that you really like the article, and I think that I brings up some good points and wrote a good article. However, I don't agree with either of his responses above.
jcarlilesiu is offline   Reply With Quote
Old 04-29-2010, 06:36 PM   #28
Aquarium Advice Addict
 
Join Date: Apr 2010
Location: BC, Canada
Posts: 2,398
He isn't stating hard facts... he is saying it "shouldn't" collapse and that the "floor could be stronger than the 40lbs psf minimum in MANY places" Are you saying that you shouldn't walk on a floor because you exceed "X" 220lbs psf...?
__________________
Sometimes life is best left to it's own devices.
If your not happy at what you're looking at, you're looking at it the wrong way.
My 320g tank build in progress watch at ---> http://www.aquariumadvice.com/forums/f71/320g-build-journey-experiment-128784.html
Greenmaster is offline   Reply With Quote
Old 04-29-2010, 06:45 PM   #29
Aquarium Advice Addict
 
Join Date: Aug 2005
Location: Chicago
Posts: 1,020
Send a message via Yahoo to jcarlilesiu
Quote:
Originally Posted by Greenmaster View Post
He isn't stating hard facts... he is saying it "shouldn't" collapse and that the "floor could be stronger than the 40lbs psf minimum in MANY places" Are you saying that you shouldn't walk on a floor because you exceed "X" 220lbs psf...?
Look. I am not going to argue with you. If you want to take what is said in the article as gospel, go ahead. I have been doing this for a long time and have the education and experience to offer up opinions and advice which rival the author. We simply disagree on a couple of aspects.

However, I am not going to argue with you about it. If you want to place an aquarium with a point load on a 2nd story which slightly exceeds the gross uniform design load for that area. Be my guest.

As far as your question above. Being able to walk around without the floor collapsing has little to do with exceeding the design limits of the floor within the safety margin of error. Loads are also transfered laterally. Additionally, walking around is a short duration impact point load, which is much different than a long term live load which exceeds the design limits.

I am uninterested in arguing my position with you though for the sake of simply trying to "out do" somebody. I have nothing to prove, just simply to offer up help to those who may need it.

I am finished responding to the conversation unless its from somebody that has a legitimate question about the issue.
jcarlilesiu is offline   Reply With Quote
Old 04-29-2010, 07:12 PM   #30
Aquarium Advice Addict
 
Join Date: Apr 2010
Location: BC, Canada
Posts: 2,398
Sorry I should apologize. I like to debate as it often helps people to see both sides of an argument and come to an understanding. I didn't mean to offend you.
__________________

__________________
Sometimes life is best left to it's own devices.
If your not happy at what you're looking at, you're looking at it the wrong way.
My 320g tank build in progress watch at ---> http://www.aquariumadvice.com/forums/f71/320g-build-journey-experiment-128784.html
Greenmaster is offline   Reply With Quote
Reply

Please support our sponsors and let them know you heard about them on AquariumAdvice.com

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
I think I will get that larger tank.. jm667 Freshwater & Brackish - General Discussion 6 03-13-2009 03:29 PM
Ich precautions gzeiger Freshwater & Brackish - Unhealthy Fish 6 10-22-2008 05:09 PM
2 questions leveling tank and precautions to take for 2nd fl eddiedellz Saltwater & Reef - Getting Started 3 10-08-2006 01:15 PM
Vacation precautions cinciboy Freshwater & Brackish - General Discussion 13 07-11-2005 10:57 AM
Larger Pump ???? Thumper General Hardware/Equipment Discussion 5 02-17-2005 01:20 PM







» Photo Contest Winners








Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -4. The time now is 03:06 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.