I'll start by saying I'm not perfect. I've learned some things the hard way that I could have avoided, which in part spurned this whole blog. This week's topic covers one of those things learned by trial and error (but mostly error).
If you are responsible for fire protection bid plans and you expect a contractor to provide hydraulic calculations, then you should include flow test information on your plans.
"If you are responsible for fire protection bid plans and you expect a contractor to provide hydraulic calculations, then your plans should include flow test information."
NFPA 13 does just about everything but require a flow test to be completed on the preliminary plans.
Annex material, for instance, has long spelled out that preliminary plans should be submitted to the AHJ prior to the development of working plans by a contractor (A.14.1 in 2002 Edition, A.22.1 in 2007-10, A.23.1 in 2013-16, A.27.1 in 2019). These preliminary plans should include test information with date and time, conducting party, location of hydrants, and size of mains.
Water supply information is a critical part of the overall fire protection equation but it's value comes before bidding as well as after.
If it is not a requirement in 13 to have it included in preliminary plans, then why provide it when the contractor can?
Well, there are several reasons.
1. Determine Fire Pump & Water Storage Tank Prior to Bidding
Is a fire pump required for the project?
It’s an important question – the cost impact to an owner is often between $50,000 and $120,000 between the pump, controls, piping and equipment, and possible generator when a pump is required.
The only thing more expensive than a fire pump or water storage tank included on a project
is when they get added as a change order.
Is the available flow to the site low, needing a break-tank or a full water storage tank?
The cost impact to an owner here is even greater.
If a flow test is not included on preliminary plans, how is a contractor supposed to confirm that a pump or a tank are not necessary? Take the word of the engineer? Guess based on past-history?
For flat-terrain areas with little construction activity over time, anticipating the available supply might be possible. For hilly areas where I live with a wide variety of water main sizes, it can be next-to-impossible to guess an available water supply at any given location.
If you are a prudent contractor and you are to bid a job without clear water supply information, what would you do? Bid a price conservatively high to anticipate large pipe sizes with a poor water supply? That’s possible – but then you’re also far less likely to win the job. Bid a competitive price, but exclude larger pipe sizes or a fire pump/tank? That could work to win the job, but what happens when the actual flow test is run and you determine a fire pump is necessary?
I’ll tell you what happens – the owner gets a very large change order they weren’t anticipating and the general contractor, sprinkler contractor, and design team all look bad.
Part of my role is creating upfront preliminary plans for owners & architects that go out to bid, but I also work for sprinkler contractors to produce installation/shop drawings. I’m very fortunate in that I get to see both sides of the industry.
A Real-World Example
One current job that I’m working for a local sprinkler contractor on is a new-construction five-story medical office building. It’s a great building with tall floor-to-ceiling heights and a fifth-story ceiling that’s about 80 feet above ground level.
The preliminary plans call for an FM Global Hazard Category-2 shelled area (0.20 gpm over 2,500 sqft) on the top level. Once the flow test came in, even with good pressure, it wasn’t enough to support this hazard classification.
Could the hazard classification get bumped down to better align with the future tenant use? Possibly. Could a fire pump be added to the project at a significant cost, late in construction? Possibly.
Either case, this all could have been avoided had flow test information been provided on the original plans. Bidding contractors wouldn’t be eligible to claim large change orders based on unanticipated pressure, and they can flag issues before they even submit bids.
2. Reduce Potential for Major Change Orders
Too often the single cost that a building owner is concerned with is the total cost of the job at bid. They should be concerned about the total cost of the project, including change orders and including the lifecycle of the system.
What good does accepting a low bid do if it is later rife with change order cost additions? It happens all the time with poorly prepared bid plans.
Including a flow test as part of the preliminary plans removes a major potential change order opportunity as it enables the sprinkler contractor to do their own pre-bid layout and calculation should they choose to do so.
3. Removes Potential Conflict of Interest
I have encountered misreadings of pressures from a gauge in the field, test results that were incorrectly copied between documents, and flow tests that were suspicious enough to go and re-test.
I (thankfully) have never come across anyone doctoring flow test numbers.
Is it possible that a contractor could fudge flow test numbers to save on pipe sizes and improve their bottom line? It’s possible. Virtually all of the contractors I’ve come across are very proud of their installations and are in the business because they care about life safety. Have I ever seen it happen? No. Could it? Yes.
When an engineer provides the water supply information upfront, however, this potential conflict of interest evaporates.
Including flow test data (or fire pump/water storage tank information) can be a critical piece
for bidders to properly assess and bid a system.
4. It’s Not That Hard to Get
For all the information we expect contractors to produce after they win a job, could we as engineers not produce such an important (and basic) piece of information?
Some water purveyors run hydrant flow tests at no cost. Some jurisdictions will do the same.
Even when both don’t run the tests, you can do it yourself. Read and follow NFPA 291, watch some videos, pickup a flow test kit for $400-$600, and remember to open and close valves slowly. It’s not terribly hard to do.
If you aren’t interested in running the test, hire a contractor. I’ve seen tests run as cheap as $150 and as expensive as $1,200 (a 3-hour drive each way), but they are often between $350 and $550 to have completed. Local contractors are more than capable of providing this service and they can do so quickly.
One of the biggest hassles in running a test early is often the tight design schedule many projects are on, and explaining to the owner why a flow test should be done upfront when a sprinkler contractor could just to it later. This article at least helps you address the later concern.
5. It’s Fair to Bidders
Bidding contractors are often not as concerned about how much or how little you want them to do. If you want schedule 40 throughout, they’ll provide schedule 40 throughout. If you want a nitrogen system, they’re provide a nitrogen system.
What contractors are extremely concerned about is that their bid price is fairly compared to other contractors. They will not provide schedule 40 if they feel another contractor will not provide it. Same with nitrogen or any other upgrades that could otherwise greatly benefit the building owner.
Water supply information is one of those key pieces of information that allow contractors to bid on an even playing field.
6. Retain Data History
How often do you find old building design documents that don’t include shop drawings? If you’re like me, it’s all the time. An engineer’s pre-bid plans don’t often have a wealth of helpful information – but having a little water supply block is a helpful data point when comparing historical water supply points.
Since engineer’s preliminary plans often get stored and tracked with the rest of the construction documents, including the water supply information can be a helpful way to retain that information for designs and renovations in the future.
I’ll slowly now descend from my soapbox by saying again that I’m not perfect. I’ve sent far too projects out to bid without water supply information than I would like to admit, often without any legitimate excuse. As an in-house goal we now try to hunt down water supply information for every project that we expect to see a hydraulic calculation by the contractor. That’s every building addition, occupancy hazard change, and every new construction project. It’s just too important of a data point to leave out for bidders.
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Joseph Meyer, PE, is a Fire Protection Engineer in St. Louis, Missouri. See bio on About page.