WrenP-Complete posted:

I'm concerned you may be right...

Bloody Hedgehog posted:

Bloody Hedgehog posted:

Bloody Hedgehog posted:

bEatmstrJ posted:

Don't worry, I'm definitely getting an engineer. At this point my speculation into how it could be fixed is only for my own amusement and trying to guess at what will really be recommended based on my limited understanding of structural engineering.

I talked to one local engineer who basically said, without looking at it, that new shorter joists would be needed to be run the full length. He wants $500 to come over and do plans, but since he already told me what he's going to do I want to talk to some other people who might have different approaches. I suspect there is more than one way to engineer out of this. I talked to another engineer in Florida for a while and sent him many pictures and he was pretty certain he could engineer a solution that wouldn't require replacement, but once he found out I was in CA he said it wouldn't matter cause his plans wouldn't be accepted in my state, which I personally think is silly since engineering doesn't change from state to state (even though code does).

I figure my worst case scenario is new beams get installed and I'm back with no sunken tub. My 2nd worst case scenario is shorter beams get installed and I get my sunken tub but its a very invasive process. The best possibility is someone retrofits my existing beams to work in place.

I'm going to try to pick the brains of the project managers that come over and see what I can learn from them and hopefully get some additional leads on engineers, cause they aren't terribly easy to find, or at least I don't know how to find them around here.

Bloody Hedgehog posted:

Evilreaver posted:

Man, I missed KS's allegedly sweet avatar did anyone 'archive it before the evidence was erased'?

Bloody Hedgehog posted:

brugroffil posted:

Engineering licenses are state by state, and while many have reciprocity, California is extra special thanks to earthquakes.

WrenP-Complete posted:

And this moss wall!

xwing posted:

This. California and Florida that I know of have stricter reciprocity rules. CA has special earthquake exams and Florida has hurricane requirements. I've heard Hawaii just adopted Miami-Dade and Florida's product approval guidelines and doesn't know what is going on. My understanding also is that Los Angeles has it's own special snowflake requirement above and beyond the CA ones.

My advice... get off Yelp and Craigslist. Find your local Builders Association. You can likely call them up and get a list of contractors that you'll be way more satisfied with. If a contractor doesn't care about pissing others off they won't be a part of an association. Chances are if they can't be bothered with you they're probably annoying their subs which doesn't go well if you're in an association together to promote local construction.

And yes, there's going to be more than one way to engineer out of this problem.

brugroffil posted:

You can try Angie's List too since it's free now.

Burt Sexual posted:

I didn't know that! What's the biz model now? Ads?

Burt Sexual posted:

That's actually not a bad idea, but they'll say tear our the floor. 😟

Bloody Hedgehog posted:

Beet Wagon posted:

This is one of those things that I look at and go "Holy poo poo that's dope I'm doing that in my bathroom" but then I remember that I live in a normal middle-class home on a cul-de-sac and not a Tom Cruise science fiction movie and if I made one of my walls out of moss I would never be able to make the rest of my house look future-ey enough to match it.

Effective-Disorder posted:

I just reread and rethought on this. This most likely will not solve your problem for the same reasons the scarf joint sister project won't. With all of the parts in between, there is no way to be sure of it without knowing anything about how these parts are intended to interact. Like I said, they did the math, knowing all that they know, when they published that technical bulletin, and as follows, they can only account for the cases outlined there.

Also bathtub, incase you forgot. Bathtub right on top of the pivot point for the whole mess. Not good.

I apologize if I led you to some kind of hopeful idea about things by showing you that document, but my point was that your situation is way out of the scope considered there, and you'll definitely need someone who knows what they're doing to figure out a solution. And, even though your stalker was a total nutcase about it, he did have a point about inspections and permits. Those parts come with a stamp on them because someone did all the leg work on calculations for you. If you change those parts, that stamp doesn't mean gently caress all for insurance, permitting, etc. You could be setting yourself up for a serious financial issue down the road.

Bloody Hedgehog posted:

Mr. Mambold posted:

Ok sure thing Poindexter. Add glue to the screws and I'd bet a structural engineer other than Groverwould sign off on it no worries. Or you can bolt steel in the same way.

Bloody Hedgehog posted:

brugroffil posted:

Engineering licenses are state by state, and while many have reciprocity, California is extra special thanks to earthquakes being California.

WrenP-Complete posted:

I'm a therapist and researcher/data scientist, I took physics in college but don't remember it. Can someone please explain what second moment means?

Neutrino posted:

I graduated with a BSCE in Structural Engineering. The first moment is when you say "Oh poo poo! The second moment is when you break your spine.

WrenP-Complete posted:

I'm a therapist and researcher/data scientist, I took physics in college but don't remember it. Can someone please explain what second moment means? And sheer vs compression sounds familiar but I also don't remember that part. Equations are fine! I figure if I don't know, other people don't either, that's why I'm asking itt rather than googling.

WrenP-Complete posted:

I'm a therapist and researcher/data scientist, I took physics in college but don't remember it. Can someone please explain what second moment means? And sheer vs compression sounds familiar but I also don't remember that part. Equations are fine! I figure if I don't know, other people don't either, that's why I'm asking itt rather than googling.

Bloody Hedgehog posted:

Adiabatic posted:

Howdy!

I lurk a lot over here in DIY, and was super curious about your predicament.

Before we get started, I am a mechanical and electrical (not civil/structural/architectural) engineer, and I do not have a PE license. Therefore:

DO NOT USE ANY OF THESE VERY BASIC AND GENERALIZED ENGINEERING CALCULATIONS AND PROBABLY WRONG SOLUTIONS TO MAKE ANY SORT OF DECISION ON YOUR GROVERBATH

Anywho. Exactly how badly did you gently caress up?

Engineered I-beams are made using dimensional lumber as the flange sections, with some thin particle board as webbing. These individual components suck at compressive loading in the directions they're sitting in, but they have been engineered in a very important cross-sectional configuration so that the sum of the parts come out much better for use as joists.

Your funny picture shows the name "TJI 230" as your floor joist. Here's its cross-sectional dimensions:



Let's go for broke and assume a 16" OAH.

I had to google the density conversion for like, normal softwood density, because engineers are very bad at basic math:



Using this cool I-beam cross-section calculator because engineers are very bad at basic math:



Okay so there's your normal cross-sectional wondercalcs. With these random numbers you can calculate a bunch of stuff like how many Clevelands you can fit in the bathtub on top of them.

With cutting off the top dimensional lumber piece to plop in your awesome black mold infinity tub flush with the floor despite every picture I see of them having a raised floor, you have effectively made all 14' of your engineered I beam an inverted engineered T beam. Generally speaking, the remaining top flange is now useless for compressive loads (see infinity tub).

Here's that good poo poo:



Note you reduced your second moment of area to 40% of its original value ahahahaha

With a 1000 lbf load on one beam in the center, before cutting:



After cutting:



So you doubled your deflection, and increased the stress on each beam by about 2.3x. This "hosed factor" scales for whatever load you want to put on it! Honestly I thought it'd be much worse. At any rate, hopefully the safety factor on those beams is was more than 2!

Adiabatic posted:

Compression loads are loads due to pushing against something. Tension is pulling. When you put a load on some object you put stress on that object. Shear is a particular form of failure of that object due to the stress induced. I'm wrong on this shear is another form of loading per bone diagram.

Nevvy Z posted:

I don't think you are wrong. The diagram merely shows the direction shearing forces would come from and how they relate to one another. Specifically, a slight offset that causes strain rather than rotation. You could theoretically shear at all kinds of angles, I believe.


Definition of noun:a strain in the structure of a substance produced by pressure, when its layers are laterally shifted in relation to each other.
Definition of verb:break off or cause to break off, owing to a structural strain.

socketwrencher posted:

bEatmstrJ posted:

That being said, my last home had an extensive bathroom remodel without any permits and there were no issues when it was sold.

You might consider rethinking your takeaway from this anecdote.

Yawgmoth posted:

I am learning so much from this thread! Most importantly, I have learned that if I ever own a home I should not touch a drat thing re: remodeling unless I talk to at least one coworker (most of my coworkers are architects/engineers).

Adiabatic posted:

You can totally do it yourself, just be sure to research the poo poo out of your local codes. There's quick reference books online and they cost like $15 for each discipline. It's important to take a positive attitude with building code because you bet your rear end it's there for a very practical and important reason. I personally find it fun to figure out why, but that bit's not necessary as long as you follow them to the letter.

Adiabatic posted:

Compression loads are loads due to pushing against something. Tension is pulling. When you put a load on some object you put stress on that object. Shear is a particular form of failure of that object due to the stress induced. I'm wrong on this shear is another form of loading per bone diagram.

Hope that clears some stuff up!

angryrobots posted:

I'd like to add, when thinking about how any beam is loaded, the upper part of the beam is in compression, and the lower part is in tension (in this case, load being in the same direction as gravity).

brugroffil posted:

I forget what the more abstract definition of second moment is, but it's symbol is "I" and it's critical for lots of beam calculations. Higher means stiffer/more resistant to bending.