Structral engineer ??s

[papajojo]

Hi all,
I live on the second floor of a condo. I currently have a 125G tank on an non load bearing wall. My question is this. The floor is made of 4inch concrete(unknown if it is rebarbed or not). i was interested in putting a 180g with the 125 to be used as a sump so probably at ~75 working gallons. That being said I had read that per inch of concrete was a compression breaking point safe load of ~1,000 lbs per inch(unknown if this figure is rebarbed or not) so any help out there would be greatly appreciated.

Also i was going to move the tank to be set up caddy cornered on 2 weight bearing walls giving me ~4 square feet behind it

Is this a safe doable project?
i don't really want to have the floor collapse
should i just have someone come look at it? and if so about what cost would i be looking at for this analysis.

The plans for the building are from the 1980s so Lenar homes doesnt still have them.

Any help would be greatly appreciated.

i am having trouble uploading the attached html sorry

 

[papajojo]

crud

crud

wrong spot on the forums sorry

 

[circusordie16]

i would say have somebody come look at it if youre concerned. theres a lot of variability in concrete strength and reinforcement (rebar) and construction so its pretty hard to accurately say what you have. additionally, the concretes not gonna break in compression, the problem would occur from the bending from the weight that causes tension in the bottom of the floor. so id say try to find your plans and have someone look at it although im betting that youre pretty safe with a concrete condo.

 

[adamsaranluke]

4 inches of concrete on the second floor? I dont think so. Are you sure the floor is concrete? I cant imagine that a subfloor would support that much weight. And I cant think of any practical reason to pour a 4 inch slab on the second floor. How did you come to the conclusion that your floor is 4 inches of concrete? If by some chance it is concrete, it would definetly need to contain lots of rebar, a wire mesh and probably be post-tensioned to keep it from crumbling when the rest of the house settles, which it definetly will with a 4 inch slab on top of it. I only have one area of expertise, construction, and I like to put in my two cents.

 

[papajojo]

yes I am sure

yes I am sure

yea im sure its 4 inches thick the reasoning I dont really know why they did it but they did, ive replaced my tub and had to access the downstairs unit to do so. and yes ive also drilled through the concrete in another area of the house for the ro unit to have a drain(from the kitchen through the floor to link with the bathroom plumbing).anyhow i have a consultant coming over hopefully on the 4th to sign off or end this project. thanks

 

[DNickell]

Another 2 cents worth: Back in the seventies I worked for the Highway Engineers when I was out from college for the summer. I worked my way up to "construction inspector" level way faster than I should have, and found myself running the slump and air and other tests on the concrete for bridges being built for an interstate highway.

I can tell you there is an amazing difference in the strength of concrete varying from the mix to how the rebar and mesh is put in, how it is cured to expansion joints, dry joints, etc.

I can also tell you that I about got fired for putting on paper that some of the loads of concrete were not passing the on-site tests I was running as each truck began pouring. I was told to put on paper that the concrete passed and send word back to the plant to modify the mix. I think about that everytime I drive over, or under, a bridge. Having good codes in place does not assure the structure is as sound as it is supposed to be.

Kuddos to you for bringing in a consultant. That is the right move. A certified inspector that would sign off on it would be even better. If you get a good inspector (s)he will have access to the records on how the concrete floor was (supposed to be) constructed.

When I put my 120 gallon into the first floor of my farm house (built in the 1840s) I took out the flooring where the tank would sit and put concrete reinforcements below frost level for the joists. When it comes to construction, overkill is a good thing.

 

[papajojo]

thanks

thanks

thanks for your time.
i was thinking the same thing also im sure that much has changed since they were built.
i was basing my calculations on modern concrete and i have no idea whats actually going on in there etc

what do you estimate the charge will be theres a 85$ inspection fee for them to gather the plans and do an analysis anything else i should expect or is that about it?

 

[DNickell]

Re: thanks

Re: thanks

<a href=showthread.php?s=&postid=13078010#post13078010 target=_blank>Originally posted</a> by papajojo
what do you estimate the charge will be theres a 85$ inspection fee for them to gather the plans and do an analysis anything else i should expect or is that about it?

Out where I am there is a standard inspection fee stated before the inspector arrives. If you give the guy a beer there won't be any additional charge. Give him two and you may not have to pay the regular fee.

I suspect Tampa is a bit more formal on these sorts of things.