When the inevitable new project gets handed off to the fire sprinkler designer, many of us feel tempted to immediately open up the drawings to the reflected ceiling plan to get an idea of the project scope. However, just referencing these drawings is not sufficient enough to familiarize yourself with the entire project. Over they years, I have developed a simple and helpful way to become familiar with a project during the start-up phase and it may help youtoo. What I do is simply follow the architectural sheet index/table of contents in order. If you look at one, it’s organized in a fairly logical order and flow of work. It usually begins with some kind of general information sheet, and life safety plan, then to the site/civil information. Next the architectural drawings and then to the structural and mechanical trades. I will explain why following this flow of drawings can be very helpful.
General Information Sheets: These sheets usually indicate which version of the codes and standards the drawings were permitted under. Typically the codes to be used will be your current adopted state or local codes. However, I have had projects in the past where the building was permitted under previous versions of the state building code and was now being constructed under a new set of adopted codes. There is not a lot of information to be gleaned from these pages, but it sets up the context for the codes that are to be used.
Site / Civil Plans: In these plans we get an idea of how this building fits into the local area. Typically most of our information comes from the Utility Plans. Here we find out how the underground water system will supply the fire sprinkler system, what configuration it is in, and the location for fire sprinkler risers, backflows, hydrants and fire department connections. If the system is to be fed from a city water supply, in the back of my mind I am asking myself; is this supplied by a gridded water system, a dead-end line, or is there a sizable elevation difference between the test hydrant and the building. All of these will affect the hydraulic calculations to some extent. If it is a dead-end main supplying the system and the hydrant is located a far distance from the building, I need to be wary of how I layout my sprinkler system. Perhaps a gridded sprinkler system may be best to use in this case, or standard spray sprinkler may be preferable over extended coverage heads. If the water supply is from a fire pump then I may decide that my sprinkler system configuration is not such a critical concern at this point. Any type of water tanks should be noted on these plans as well.
Architectural Plans: This set of plans are the ones most used in our sprinkler system design. However, the fire sprinkler designer needs to become familiar with all the drawings in this set, not just the reflected ceiling plans. Sheets like the Building Cross Sections will give you an idea of the building height and any pressure issues that may arise from taller buildings. The Life Safety Plans indicate firewalls and rated walls, plus any areas of refuge that sprinkler pipe should not encroach on. I could go on and on but you get the idea. Our job as fire sprinkler designers to familiarize ourselves with all aspects of the building so that we correctly design our system and the fitters in the field can quickly install it without any issues.
Structural Plans: From this set of plans we find out the type of structure we will be supporting your system from. Questions I ask myself are, is the structure combustible or not? If so, additional sprinkler heads may be required for those areas. If the structure is concrete, is it post-tension, poured concrete, or hollow core slab? If it is post-tension, extra care needs to be taken with any pipe penetrations to avoid the steel cables, and if concrete inserts are to be used, shallower inserts need to be selected to avoid severing the cables as well. If the concrete is a hollow core slab we need to look out for bond beams used to support the structure. The coring drilling of bond beams is expensive and can be done only occasionally as approved by a structural engineer. Typically the structural engineers frown upon the idea of too many holes in their beams. If the structure is solid steel beams, are they spaced far enough to be considered unobstructed or obstructed construction? This will impact the fire sprinkler head layout in open areas without ceilings.
Mechanical Plans: There is not much critical information to be gleaned here. Perhaps we can find out if there are VAV boxes with filter access areas that need to be avoided with our piping.
Electrical Plans: It’s always good to locate where the electrical panels are in the building so that your sprinkler pipe can be routed away from these areas. Also, the Light Fixture Schedule should indicate which light fixtures are recessed and which are surface mounted and therefore an obstruction to the sprinkler spray pattern.
Plumbing Plans: I typically will look at the area where the fire sprinkler riser comes into the building and make sure there will be enough room for the pipe and valves. More then enough times the plumbing engineer has put a domestic backflow assembly or storm drain in the location the fire riser was supposed to be.
Fire Sprinkler Plans: These plans are obvious. If the sprinkler engineer has done their job, we find out the parameters in which our system is to be designed according to. Unfortunately, most of these drawings that we see are typical notes and details that may or may not pertain to the specific project and it is left up to us to do what is best. I am not going to discuss much more about Fire Sprinkler Plans since all of us should be familiar with them by now.
If you have any additional items that you look for in your initial project evaluation, leave a comment in the comment section below. I would like to hear about it.