Usually, the very first question I get from an architect when they're early in conceptual design or schematic design is how much space do we need?
There are a few considerations I have to make at this point.
If best case we have a vertical shotgun riser with a single wet zone for our sprinkler system, then I really might not need that much space, but I still have to coordinate it. I need space for the underground to step up into the building, space for that flange and backflow preventer with three feet of access in front of the backflow preventer, and access on both sides so that installers can work around the equipment and have enough space to hoist all of the equipment into place.
I also need to think long-term when that backflow preventer has to be replaced someday, is there enough room that it's even possible?
As a very, I'll say very rough rule of thumb, if I have a vertical riser with a vertical backflow and a single zone wet pipe sprinkler system, I will generally ask for a space about three feet wide and three feet deep with three feet of access off the front, coming off an exterior wall for that riser. So total, if our pipe is offset off the wall, we're looking at a space that's about three feet wide by about seven feet deep on an exterior wall.
For a fire sprinkler system that is usually about the absolute minimum amount of space that I could need. My space needs only get greater and greater from there.
If I have a horizontal backflow preventer with a few zones above it, then I'm usually asking for a space that's maybe seven feet wide, three feet deep with three feet of access in front. So if my equipment say a foot off the wall, that's about seven feet wide by about seven feet deep on an exterior wall.
Here, we need space for the underground to come into the building, we need space for the pipe and equipment itself, and we need clearances for maintenance and repair in the future.
If I'm working on a fire pump room and the space gets a whole lot trickier. I've been asked multiple times over the years that you have to ask for more space than you end up needing at the very end of a project. It's like a shady back-alley negotiation for space whenever you're sizing your fire pump room. If you ask for only the bare minimum at the beginning, the bare minimum you could possibly work with, then as the design progresses and room shift and walls change little by little, you may actually run out of space. Once a fire pump room is designed and goes out for bid, it's really hard to get that space back. I'll also say that just as things shift and progress over time, space becomes more and more valuable. It's easy to give space back to an architect. It is very difficult to ask for more space.
For most projects with a single fire pump, that's not a crazy large fire pump. Let's say something like 1500 GPM are smaller than I usually start out asking for a room that's about 15 feet wide by 18 feet deep without any columns or giant footings right underneath the room. That's usually enough space to make somebody go into orbit, but it ends up being a starting point for negotiation and if I can bring the fire pump size down or use a vertical inline pump or something that saves space, then I can usually start giving some of that room back to the architect. The further I get along the design, the more I'm able to dial it in and put everything exactly where it needs to go. Hopefully at the end, I'm shaving down the space that I need, and I'm able to give some of that back. Worst case, the room has to stay at the size that it's been given and everybody can move forward. What I don't want to happen is to ever have to ask for more room.
When coordinating fire pump rooms, just be clear and realistic about why you actually need it. The fire pump needs to be able to be removed and replaced with room to turn and bring in a hoist and have the correct clearances all around it. I once had a project that was maybe 12 feet by 8 feet wide and in theory, it was possible to make it work, except the architect left a concrete column right in the middle along a wall with a giant square footing below it. So, with the giant footing, my underground stub-in was limited in where it could go, and the column prevented a nice clean fire pump assembly along an exterior wall. It was awful to work around. An open rectangular room is a whole lot easier to work in and move around than an L-shape room or a room that's filled with structural columns or a room that has a giant foundational footing that has a giant footing right underneath it.
If you want to make friends with the contractors that are bidding your drawings, then do a good job of coordinating the space needed for the equipment. If there's a fire pump on a job, get a rough layout, make sure that there's at least three feet of access around any edge of the equipment. I say, making friends with the contractors, they may still hate you for other reasons, but at least you got a good start.
We also want to think about future replacement needs. If we have a large, say horizontal split case fire pump that's on a skid, then we're probably going to need double doors for the room to make sure that someone can replace that pump someday in the future. It might be slightly more expensive now to have a set of double doors instead of a single door, but it'd be a whole lot less expensive than ripping out an exterior wall to get that replacement fire pump to happen in the future.
The other important thing to consider is where the space is located. It's not enough to say that I need a six foot deep by three foot wide space from my vertical backflow preventer riser. And then the architect ends up locating that right in the middle of the building. I need to make it clear that it should be on an exterior wall near where we plan to have the water coming into the building. I see far too many projects that go out for bid that have a sprinkler riser located literally in the middle of a building with an underground line that would run 40 feet or more underneath the building. NFPA 13 clearly gives us guidance that we can't run underneath buildings without taking a whole lot of expensive precautions. If we get a main break, now we're excavating concrete and tearing apart the building to repair a main that honestly just doesn't have to be run under the building in the first place. We need to make sure that when we're coordinating the space for making it clear that we want that along an exterior wall.
If we have standpipes, then I also need to coordinate space wherever those hose valves and vertical pipelines are going to be located. Are my standpipes exposed in the corner of a stairwell? If they are, I need to make sure that the standpipe and the hose valves are not impacting egress along those stairs. Is a room for occupants to move as they egress the building? Are my hose valves too far off the vertical pipe that they would potentially impact ADA requirements for visually impaired people? It might sound a little ridiculous initially, but when you think about a building that's having an active fire event that may or may not have power, and we're trying to get somebody to egress the stairs because the elevators are shut down who isn't blind but has visual impairments, and they're going on a stairwell, we don't want to surprise them with a hose valve that's sticking too far out into the egress pathway.
In general, for standpipes, I'll try to locate that vertical pipe as far into the corner of the stairs as possible, and then offset the drain riser so that they both fit within the landing of the stairwell but it's out of the way as much as possible.
If we have hose valves that are somewhere outside of a stairwell, do those need cabinets? Do we have to frame out a thicker wall in order to accommodate a two and a half inch, a four inch, or six inch pipe that goes into that wall? Is it big enough that we would need to chase? Those are the things we have to think about when we're coordinating space needs with an architect.
Lastly, we've got to think about any remote valves or remote fire department connections.
If we have a dry system that is serving an attic, and we want to locate that dry valve on the highest level of the building, then we may need some space in a closet or mechanical room to accomplish that. A dry valve itself could need a space that's maybe four or five feet wide by about six or seven feet deep if we want to make sure that we have really all the required clearances that we need.
Now, if we have a fire department connection that is on the street face of a building, do we have room to route the pipe down to that fire department connection? If we're feeding up from below, do we have room to come up from below and get to the fire department connection? Do we have enough space that we can have that ball drip below the fire department connection elbow that's required so that it drains and doesn't freeze?
A lot of times the street facing side of a building has the most visibility. There might be a big storefront or executive offices or some kind of high value space, right at the front of the building. If we want to get a four-inch pipe to the fire department connection in those areas, we may need to carve out space near a structural column or a chase, or really coordinate something with the architect to get that pipe in.
At the end of the day in coordinating space with architects, I have to first think about big picture what my system is going to need. Will one zone work for the entire building? Can the backflow preventer be vertical? If that's the case, I might need only three feet wide by six or seven feet deep.
Will my service entry have multiple zones or will it need a horizontal backflow preventer? If that's the case, I'm going to need a wider space, but still about the same depth.
Will we have a fire pump room? Then the coordination becomes much more involved, but rough sizing from the beginning of the project would be just as helpful for the architect so they can reserve and dedicate that space for us.
Do we have standpipes? If so, we'll want to locate the standpipe risers and hose valve locations and make sure there's enough space, wherever those need to go.
Do we have any remote valves or fire department connections? If so, we're going to need to carve out some space and make sure we have access to those locations. If you're coordinating space early on in a project, exact dimensions are not really necessary. Just be slightly conservative and make sure you coordinate the space you'll need, and when you get to the point that you're able to detail that riser or valve or the pump room, then you can really dial in the exact space needs and give back the extra room if you have it.
I'm Joe Meyer, this is MeyerFire University.
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