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Discussion Forum

Plumbing drops and Floor Layouts

BossHog | Posted in General Discussion on March 28, 2005 06:48am

Someone from BT brought this up to me via email.

As some of you know, I do truss design and layout. When a floor layout is done, who should be checking plumbing drop locations against the truss layout?

I’ve had customers ask me to show plumbing drops on layouts, and have attempted to do so. But I’m not always 100% sure that they’re right. And I may not know exactly where walls are going to land, or if a customer/owner has changed things around a bit. So I’m not sure how much value there is in it.

So how do y’all handle this. I hope some of you will chime in, although I know most of you are shy about sharing your opinions.

(-:

Knowing you has put a song in my heart.
But the fat lady in the viking helmet is really starting to annoy me.

Reply

Replies

  1. Hubedube | Mar 28, 2005 07:44pm | #1

    If you are the one designing the truss layout, then obviously you take into consideration where the walls occur, roof loads,etc

    But why be concerned about the location of  these plumbing drops?

    Are you  also concerned about the heating duct drops, central vac, phone cable, the electrical boxes,etc. NO.

    So why not just stick to your end in the designing of the truss work, and let the other trades people do their own designing in order to accomodate what you have drawn.

    Afterall, like you, they too are skilled in their individual trades. 

  2. User avater
    CapnMac | Mar 28, 2005 07:55pm | #2

    customers ask me to show plumbing drops on layouts

    Since you are really supplying "shop drawings," I'd be inclined to put some sort of qualification like "Mechanical and similar items shown on plan are representational, and reflect only the information available on [drawing date]."  You might could add, "Plumbing & Mechanical items shown for informational purposes only, consult final architectural drawings for actual locations."

    But that's just noodling off the top of my head.

    Occupational hazard of my occupation not being around (sorry Bubba)
    1. FramerT | Mar 28, 2005 10:54pm | #3

      Too many variables,changes,etc. Lead guy might bring his lay-out from a different end.
      Bath walls might get changed in size due to something.
      Toilet centered or not.
      Whirlpool drain, which end?to name a few more.
      I didn't do it....the buck does NOT stop here.

  3. djj | Mar 28, 2005 11:48pm | #4

    Boss,

    I am just an O/B so take my post with a grain of salt. When I submitted prints to the truss company to design the floor system, I made sure we had dimensions and notes on the prints for where plumbing drains needed to be located. When I got my proposed floor layout from the truss company, the designer had put a couple of the TJI's right in the middle of a drain location for a toilet or tub. A couple of them were within the 4" allowable for site adjustments. But for the ones that weren't, I had him change the layout to give us the clearance we needed. Then I made sure that my framers paid close attention to the layout so that the joists ended up where we expected.

    Others have said that you shouldn't worry about it and let the various trades figure it out.  In some cases this may work just fine; but at least on my house, it was cheaper and easier to fix problem earlier in the building process rather than later. But as the truss  designer, I don't think it is your responsibility though to worry about this if the specs aren't provided to you by the GC or architect.

    Now if only I had given the same amount of thought as to where I wanted to put can lights when we had the roof trusses designed....Live and learn.

    Kind regards,

    Dennis

    1. User avater
      BossHog | Mar 29, 2005 01:35am | #5

      "I am just an O/B..."

      Is that Owner/Builder?

      Or short for OB/GYN ???

      (-:

      I wouldn't object if folks did something like what you did - Give me the locations.

      It bugs me a little when they want *ME* to figure out where the drops are and then they don't double-check 'em.

      I don't like the "let the various trades figure it out" version. Plumbers are well known for hacking up floor systems. Better to avoid problems up front.

      But SOMEBODY has to do the checking up front. Hence my original question:

      Who should be doing the checking ???
      I have this nagging fear that everyone is out to make me paranoid

      1. Framer | Mar 29, 2005 01:45am | #6

        Boss,I don't use Trusses but I still stick frame all of my roofs and never once was plumbing ever thought about with the roof. I always layout my joist for the plumbers and if there's something I can't figure out I will call the plumber in so I don't put anything in his way but I'm not getting why the responsibility would lie on you. Your designing the roof and it's up to the framers and plumbers to work out joists locations and it's up to the plumber to run his pipes through the joists, walls and out the roof. I've never once seen a plumber cut a rafter or truss or ever heard of that.What am I missing? I've never heard plumbing drops before but I assume you mean waste line and vents running through the walls and roofs.

        Edited 3/28/2005 6:47 pm ET by Framer

        1. ScottMatson | Mar 29, 2005 02:23am | #7

          I believe Boss Hog is referring to floor trusses here. There are some considerations for the roof as well, though I must admit I've never had a truss company ask me a single thing about plumbing ever. But boss is dealing not only with framers, carpenters, and GC's but with the general public as well. They don't know the rules about plumbing vs. wood and are trying to get him to design around plumbing, maybe his company engineers floor systems in addition to trusses (LVL's, I-joists, etc.)

          1. Framer | Mar 29, 2005 02:35am | #8

            Thanks Maddog, your right. He says floor layout. I guess I just have roofs on my mind all the time.Joe Carola

          2. ScottMatson | Mar 29, 2005 02:48am | #9

            No problem, I'm mostly the same way. When I think trusses, immediately roof comes to mind, but recently worked with some floor trusses.I was really disappointed in how little room there was for hvac in those. I expected them to be really great for that part of the construction. Maybe a bad design.

          3. User avater
            BossHog | Mar 29, 2005 03:32am | #11

            "I was really disappointed in how little room there was for hvac in those."

            As a rule of thumb, I tell people not to expect to get HVAC lines in floor trusses unless they're at LEAST 18" deep.

            Otherwise there just isn't enough space to work with.
            Entropy just isn't what it used to be

          4. ScottMatson | Mar 29, 2005 03:44am | #12

            Yeah, these were pretty deep, in that range but I'd have to check and see how deep they actually were. Pretty nice to work with, but there were a couple places where they were tripled. Seemed like overkill to me, "but whata I know"?I'm with Framer, the carpenter or GC who lays out the floor system is responsible for getting the plumbing clear. There have been some good articles in FHB about the various clearances/tolerances but mainly I try to get the closet bend, the tub and shower drains clear and not get plumbing walls too close to structural members. Usually I talk to the plumber but I have found that almost no other builders in my area ever let them give any input--but I find hacked up joists all the time, even I joists cut clean through!

          5. ChuckNewcomb1 | Mar 29, 2005 07:50am | #13

            I believe I was the one Boss Hog refers to when he says someone emailed him about this topic.

            The last framers before us did not move the trusses over where the waste drains were, and we were paid to go back and sister up sections that the plumbers literally ripped apart.

            So I had planned to move my joists on my job and not have to go back at my expense and fix stuff. But what do I get but a set of prints with the bathrooms circled in red saying..."change". So I said screw it and set the joists on layout. Im sure one will hit a tub drain somewhere. Ticks me off though cuz it could save alot of hassle. But wheres the builder when ya need him.

            I agree it should be my,...the framers, job. Whenever I am able to offset my joist for waste lines, the plumbers are much nicer when we do punch out and they are around. I even try to teach my newbies to nail the very top plates over top of the studs so the other trades dont chew up drill bits.

            Some of our houses have the whole side wall full of plumbing and duct work....in those cases I set my first joist 19.2 off the end so they can get all the junk in there.

            Chuck

             

            Edited 3/29/2005 12:51 am ET by chuck

      2. Framer | Mar 29, 2005 02:49am | #10

        Sorry Boss for my first post even though you said floor layout, I just thought Roof Trusses. Still I've never seen a layout that allows for plumbing from a truss company and it shouldn't be up to you, it's up to the framer to move joists out of the way for the plumbing and if the framer can't figure it out he should call the plumber to help.You can draw lines where the trusses can go but the framer is the one that will pull his measurement from wherever he wants to and if a waste line lands in the middle of one of his 16" centers then he has to move the truss out of the way.You said it's better to avoid problems up front which is right but it's up to the framer as to the place the trusses in the right spot not you. If the framer puts a beam in the center of a waste line then it's his fault and he should pay to fix it.The first thing I ask is if the bathroom layouts changed at all and if not I layout the way they are on the plans, if they change the layout and there's a joist in the way it's not my fault.I can't see how the truss company has to layout for the plumbing.The Framer and Plumber is responsible not you.Joe Carola

      3. blue_eyed_devil | Mar 29, 2005 08:02am | #14

        Boss, the guy drilling should know where/what his drill is hitting.

        I've been victimized a coupla times where the plumbers just hack through the floor trusses. Sometimes, I should have known and should have not put the joist there, other times some other circumstances occurred that changed a hole location.

        I think the truss layout should identify and account for problematic plumbing and heating holes. In the absence of these idendtifiers, I'd recommend the following warning.

        WArning, if a plumber or heat man cuts this truss, he should immediately expose his genitals and allow the carpenters to lop them off!

        That probably wouldnt help, the plumbers would still stupidly cut through things that shouldn't be cut,  but I'd feel better.

        A long time ago, I was going back to every house for ONE item missing that caused us to pass rough inspection. It was the center block that was installed to catch the top of the access panel on tubs, and provide firestopping. I went into a house and the young plumbers were still in there and had knocked the blocks out on four different tubs. I asked why. "because the boss told me that this was the first thing you do!". I replied " please tell your boss that I have had to come back and make a service call for every one of those blocks you've knocked out. If I ever come back again for one, I'm going to sawzall all that copper looking crap out of the way to re-install my blocks.".

        I walked out and never had to do another block replacement for that builder.

        Plumbers are idiots.

        blue

        blueJust because you can, doesn't mean you should!

        Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!

        1. ScottMatson | Mar 29, 2005 02:11pm | #15

          And carpenters are geniuses!What I'm sayin' bro,Dog

          1. blue_eyed_devil | Mar 29, 2005 03:27pm | #17

            And carpenters are geniuses

            I don't think so Mad Dog. Actually, were one step up above Chimpanzees. We are smart enough to know that we shouldn't just whack other peoples components out of the way in an indiscriminant manner.

            There was one incident where the plumber drilled a 4" hole directly through the center of a 3 1/2 floor truss. The engineering fix required a 8' piece of plywood, glued and screwed on each side of the truss. Because of the trunklines running through the truss, I was able to glue and screw a 10" piece of plywood on. Before the joist was hacked, we had two possible fixes. #1) move the joist. That would involve removing all nails, cutting the glue and sliding it east or west. #2) build a false wall behind the plumbing fixture to effectivly move the fixture.

            Since the neanderthal wasn't that sharp, and his only "solution" was to totally destroy the truss, with no chance of ever fixing it, that particular homeowner wins a 32" wide span on his house that he paid a lot of money for.

            I suppose all plumbers aren't idiots. Most are though.

            blueJust because you can, doesn't mean you should!

            Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!

        2. User avater
          BossHog | Mar 29, 2005 02:33pm | #16

          "I'm going to sawzall all that copper looking crap out of the way to re-install my blocks."

          Had to laugh at that one. There have been times I've wantd to go in and do just exactly that when a plumber screws up a floor system.
          It may be that your sole purpose in life is simply to serve as a warning to others.

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