Slab on grade drawing preferences 2

[haynewp]

I have seen drawings with floor drains indicated on the slab-on-grade/foundation plans (including ones at that do not require the slab to be sloped),and I have seen drawings with no floor drains with a note referencing to see plumbing. What all would be the reasons to show approximate floor drain locations when a slab slope to them is not required? I would think to check for footing interferences with plumbing.

 

[phamENG]

Pros:
-makes sure the GC doesn't cut the concrete sub loose on the slab before the plumber has a chance to come out.
-forces you to look at the plumbing drawings and coordinate

Cons:
-more drafting with a chance of the plumbing designer making a change and not telling you

 

[haynewp]

Agree with the potential for a change and them not telling you. For this chance, I think the best I can do is to also provide a CYA note to see and coordinate locations shown with the plumbing drawings.

I agree with the sub pouring concrete and not being aware of the drains and then having another issue.

But I think I would also want to show, before I stamp a drawing, whatever drains that I am aware of that are close to columns. This can suggest a pipe below conflicting with a footing or anchor pullout cone. And if more drains lines are added later without my knowledge, then I have some basis shown that I stamped. But I don’t think I have ever gone as far as dashing in the plumbing line locations that I designed for.

 

[MSUK90]

Can anyone of you share a SOG drawing showing drain locations?
I have never seen one.
Just wanna see out of curiosity.

 

[phamENG]

I haven't done one since my last firm, so I don't access to the drawings. Pretty simple though. It's a circle with a note or keynote that says something along the lines of "FLOOR DRAIN, REFER TO PLUMBING AND ARCHITECTURAL DRAWINGS"

 

[MotorCity]

The concrete contractor is the last line of defense to make sure that any required drains are present before the concrete starts flowing. Its easier to stop or move to another pour than it is to sawcut a pour.

 

[Aesur]

What happened to contractors who actually read and understood the plans? It really seems that now days we are having to add more and more stuff that is shown elsewhere in the "Contract drawings". Our drawing isn't the only one they should be building off of, the contractor should be reading all the drawings and not relying on each discipline to add content from other disciplines to their drawings.

I do agree that you as the structural engineer should know where these drawings are and make sure they are coordinated, however you should not need to show it on your drawings.

 

[haynewp]

Contractor's can't be relied on, at least not in my area and projects I work on. And then it ends up coming to me as an RFI to approve them cutting up the slab.

 

[Aesur]

I completely agree with you that they can't be relied upon, however we are expanding the problem by catering to them by increasingly adding more and more to our drawings/scope without being justly compensated for the extra work due to their inability to coordinate plans between disciplines. Where do we as engineers draw the line, what kind of liability are we taking on by adding other disciplines stuff to our drawings, it seems like a no win scenario for engineers.

 

[TLHS]

I do industrial facility stuff and literally everything is on the drawings, at least as a greyed out representation. The world where you get to just design your stuff and let the trades work out the co-ordination sounds magical.

 

[Aesur]

That world is magical now days for sure, but there was a time where contractors could coordinate when building. There are still a few great contractors around (older guys) who do an amazing job with this, but far more that don't seem to be able or willing to think beyond one thing at a time. Like I said, we engineers allowed the industry to get to this point by being too catering to others not "doing their job", not much we can do to fix it now. With Revit, I believe it's a matter of time before contractors require the models to be able to build things and will want LOD 500+.

 

[kissymoose]

My 2 cents, I'm all for more work to do on the design side, coordination and detailing included. It seems like a good way for clients to see value play out (minimizing problems during construction), because they certainly don't often see the building performance (e.g. L/240 vs L/360). Easily recognized value is where the money is at.

* edit: actual monetary compensation required

 

[JLNJ]

I got an RFI from a contractor asking for a layout of all the housekeeping pads in the mechanical room because “it would be a lot easier” if he didn’t have to do it himself.

 

[Aesur]

For the owner to see the value added, that would require they have and see the problems on other projects, which in most cases they are unaware of. I'm not sure if owners see all the RFI's, etc. that are generated because the contractor wants someone else to do his job for him. JLNJ hit the nail on the head there, I too am seeing simple looking RFI's like you mention that are a waste of my time if not justly compensated for their "not wanting to do their job".

 

[STrctPono]

I have no issues coordinating base files with civil, mechanical, etc., whoever.... And I try wholeheartedly to do so from the beginning. The problem is that if you are working with someone who is less than stellar, when push comes to shove and they are scrambling to make changes to their drawings last minute, sometimes things get lost in translation and there can be inconsistencies across the disciplines on the contract drawings. I guess that's just the nature of our work though.

I normally like to have input in the location of the drains since it can have an affect on your jointing plan. By treating this as "someone else's problem" and expecting the mechanical to show it correctly and the contractor to coordinate it is asking for problems in my opinion.

Here is one example of a walkway ramp leading up to a bridge with some drain inlets. It's simple enough. As long as the mechanical/civil sends you their base file, you can adjust your jointing as needed (or adjust the drain locations) and give general trim bar reinforcing details.

 

[dik]

In your official response to the RFI inform the contractor that the information is contained in the contract documents...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Aesur]

STrctPono - I agree, we have to coordinate and yes things can get missed when last minute, which this year seems to be common with many disciplines I have seen with everyone being so busy.

 

[haynewp]

I have said before that I have to make drawings that a monkey would be able to build from them. I look at it now like this, do I want to deal with it now or have the bigger headache during CA? And sometimes the fixes just aren't going to be as strong or long lasting as what was originally intended. Like a slab that has been cut up to install utilities in a building with heavy wheel traffic that will now have a lot of doweled joints at all the new sawcuts.

And some on here may say "make them tear it all out and start over" but that doesn't usually work for me. The contractor gets the owner on his side and wants a fix to keep the project moving, and then the owner expects me state why the fix won't work if I am gong to require a complete replacement. Add in the salesmen that run a lot of AE companies that want to keep the owners happy, and it starts to feel like it's me against the contractor, owner, and sometimes the people I work with.

 

[Aesur]

dik - so funny enough, I basically just said that in an RFI response; I referenced them to the detail they were asking for, that was in the CD's.

 

[canwesteng]

I would show the drains, but not locate them. Caveat that I'm in industrial.

One time I had a contractor see that there were going to be penetrations for electrical in the SOG, pour the slab and then core holes for the conduit after. So even with your best efforts they will find a way to mess it up.