Why Do You Need a Plumber for BIM?

The state of the art in BIM design is changing how we manage projects. But where does all that information come from in your Building Information Model? What BIM can do for you is only as good as the information it gives you. Remember the old saying, “Garbage in. Garbage out.” Your model must be a true representation of what will actually be constructed by tradesmen. In plumbing, state of the art BIM ain't all that!

The standard package BIM software comes with elbows and tees—fine if you are modeling small size pressure pipe for water distribution, but that's not where you need it most. As a plumbing contractor, what you need is a realistic sanitary system for coordination and take-offs. That sewer line is worthless with tees and nineties. As tradesmen we know there is a big difference in the area a long radius sweep or a combination takes than a quarter bend or a sanitary tee.

To design a true to life model that represents field conditions in coordination and real world materials for take-offs you need one of the guys who install plumbing systems for a living—someone who knows what pipe and fittings those tradesmen are going to use. An engineer may throw in a standard elbow for the design drawings, and that works fine for a blueprint, but your man in the field needs a sweep and you need to count the sweeps and quarter bends separately on your take-off.

BIM can streamline your work and make the whole job flow more efficient, but you need some work on the front end to create a realistic model that will provide you and your men accurate information. You need a plumber! Someone needs to sit down with the model, check all the fittings, streamline the design, and key in all the data for schedules so your take-offs represent what your actually want to prefab or order. Then your tradesmen in the field can use the model to make their job more efficient and make you more money!

BIM is a fantastic tool for the construction industry, that is why so many contractors are moving to it. As a plumbing / piping contractor you need to make sure the information you need is in there so it can work for you. I've been told the plumbing/piping technology in the average BIM software is as much as ten years behind the architectural/mechanical technology. It is up to us to plug in that expertise that hasn't been programmed in yet. Plumbing codes and practices are complicated. There is no replacement for the experience of a plumber in pipe design.

You Need a Plumber!

BIMing the Real World

Autodesk Revit is a great tool for design and coordination on BIM projects, but it needs a little creative thought to be realistic. The stock joins, tees and elbows, are fine for layout and design, and work well for pressure lines. They even do okay for producing line drawings. But when it comes to coordination in tight spaces every plumber knows there is a big difference in the space a tee takes out and the space a combination requires. And if you want to take full advantage of BIM in your take-offs and material schedules you need the right fittings in your model.

Charlotte Pipe andFoundry has great resources for your needs. They provide Revit families for every fitting they produce – cast iron and PVC. Plug these families into your models before you start designing and it's a lot easier to produce a solid, realistic model you can use in coordination and material take-offs. It doesn't take a lot of work, only a little advance planning. Trust me. It's a lot easier to plug in the right fitting from the start than to go back and edit a model that has nighties and tees where there should be sweeps and combinations.

The process is simple. Charlotte Pipe'swebsite has walk-throughs. You should start by downloading the Revit families, then load them into Revit. I keep a separate folder to make the official families easy to access. You also need to add the .csv files to your look-up tables so Revit can find the info it needs for sizing the fittings. Once you have the fittings you need loaded open the settings and edit how revit makes connections. The default will be set to standard elbows and tees – change that to the quarter bends and sanitary tees you downloaded if you are modeling vents or sweeps and combinations if you're working on drainage.

If you are concentrating on modeling one system at a time it works great! Intersect two pipes and revit sticks in a cast iron or PVC sweep or combination to make the connection. Done. If you go vertical and want a san. tee instead of a combo it's simple to change the fitting for that one placement with a couple of mouse clicks. When you change over to vent piping, just go back into the settings and change the sweeps and combos to quarter bends and san.tees and all your connections will use those fittings. With a little advance planning and proper settings all your fittings will be true representations of what will be installed in the field.

Once you have your model built using the correct fittings, coordination is much more useful. That standard elbow may look just fine turning out of the wall an inch below that duct, but the radius of a quarter bend is going to cut into the ceiling grid. Better to know that now than when someone tries to install it in the field and a vent or a duct has to be re-routed. You can also build a fitting schedule and revit will tell you how many san. tees and combinations you'll need to purchase instead of telling you to buy a bunch of standard tees!

Revit is all about the settings. Take the time to get everything set up before you start modeling – proper fittings and settings – and you'll love the results. Revit can be a great tool for coordination and material takeoffs if you use the right fittings in the right places. And don't neglect the settings! You have abundant control of revit's default behaviors, use it. Going back to change tees to combos later is a monumental waste of time. Do it right the first time.

One final note: You can create your own default settings and import them into each new project. That will save you tons of time up front when you start a new project. If you are a plumbing designer you are going to want all your fittings and basic settings available on everything you do, so take the time and make a settings file.