Category PLUMBER’S AND. PIPE FITTER’S. CALCULATIONS MANUAL

Keeping the numbers straight for standard plumbing fixtures doesn’t require a lot of brain space. There are very few numbers to commit to memory. The process gets somewhat more complicated when you are dealing with handi­cap or "accessible" fixtures. We’re done with standard fixtures, so let’s explore accessible fixtures.

HANDICAP FIXTURE LAYOUT

Layouts for handicap plumbing fixtures require more space than what would be needed for standard plumbing fixtures. When you are planning the instal­lation of accessible fixtures you must take many factors into consideration.

There are regulations pertaining to door widths, compartment sizes, fixture locations, and so forth. These rules and regulations are generally provided in local plumbing codes. It’s not necessary for you to commit all the measure­ments to memory, but you need to be aware of them and know where to find the figures when they are needed for design issues.

When you are dealing with a build­ing that requires the installation of handi­cap plumbing fixtures, you find yourself spread between the local building code and the local plumbing code. The two codes overlap when it comes to handicap facilities. Are you, as a plumber, respon­sible for the carpentry work? it depends upon how you look at it. You probably have no responsibility for the width of a door used for access to a bathroom where handicap fixtures will be installed. But, the width of a toilet compartment will af­fect you and your work. Most trades work well together on most jobs, but this is not always the case. If you know that rough framing done by a carpentry crew is going to prohibit you from installing fixtures with proper placement, you should talk to someone about the impending problem. Whether you talk to the carpenters, a carpentry foreman, a job superintendent, or a general con­tractor, you should raise the question of what you perceive to be a problem with the framing work. The quicker potential problems can be caught, the eas­ier it will be to correct them.

Who is responsible for the installation of grab bars? It could be the plumbers or the carpenters. This is an issue that must be addressed before a bid is given for a job. Grab bars are not inexpensive, so don’t make a mistake by omitting them from a bid price where the person you are bidding the job for expects you to include the bars and their installation in your bid. There’s something else to consider on this issue. If you are responsible for the grab bars, you are also responsible for installing proper supports in the framed walls during your rough-in work. Some type of backing, such as a length of framing lumber, must be installed in the wall cavity where a grab bar will be installed. Without the backing, the grab bars will not be solid. Finding out that there is no solid support to secure a grab bar to after a job has finished wall coverings is going to be a real problem. I’ve seen many jobs where back­ing wasn’t installed for wall-hung lavatories and grab bars. This is an expen­sive and embarrassing mistake.

Let’s talk about clearances related to water closets. There’s not a lot to go over, so this can move along quickly. Remember that we are talking about standard plumbing fixtures here, not handicap fixtures. The minimum distance required from the cen­ter of a toilet drain to any obstruction on either side is 15 inches. Measuring from the front edge of a toilet to the nearest obstruction must prove a mini­mum of 18 inches of clear space. When toilets are installed in privacy stalls, you must make sure that the compartments are at least 30 inches wide and at least 60 inches deep. That’s all there is to a typical toilet layout (Fig. 10.7).

URINALS

urinals must have a minimum distance of 15 inches from the center of the drain to the nearest obstruction on either side. If multiple urinals are mounted side by side, there must be a minimum of 30 inches between the two urinal drains. The required clearance in front of a urinal is 18 inches.

LAVATORIES

Lavatories are not affected by side meas­urements, unless other types of plumbing fixtures are involved. The minimum dis­tance in front of a lavatory should not be less than 18 inches. Obviously, minimum requirements are just that, minimums. It is best when more space can be dedicated to a bathroom in order to make the fix­tures more user-friendly.

tandard fixture layouts are dictated by local plumbing codes. Plumbing codes require certain amounts of space to be provided in front of and be­side plumbing fixtures. The rules for standard fixtures are different than those used to control the installation of handicap fixtures. We will use this chapter to cover the essentials of standard fixtures and address the topic of handicap fixtures in the next chapter. For now, just concentrate on typical fix­ture installations when you review the information in this chapter. Before we get into deep details, I want to remind you to consult your local plumbing code for requirements specific to your region. The numbers I give you here are based on code requirements, but they may not be from the code that is enforced in your area.

If you work mostly with new construction, you probably work from blue­prints. When this is the case, fixture locations are usually indicated and ap­proved before a job is started. But, remodeling jobs can require plumbers to make on-site determinations for fixture placement. A contractor might ask you to provide spacing requirements for small jobs. Knowing how to do this is important. For example, if a builder showed you a sketch, like the one in Figure 10.1, would you be able to assign numbers to the areas around the fix­tures? How wide would the compartment where the toilet is housed be re­quired to be? The answer is 30 inches. This is common knowledge for many plumbers, and codebooks define the distance. So, even if you don’t know the spacing requirements off the top of your head, you can always consult your local code for the answers.

A general rule for toilets is that there must be at least 15 inches of clear space on either side of the center of the drain for the toilet. This equates to a total space of 30 inches (Fig. 10.2). Now, how much clearance is needed in front of a toilet? The normal answer is 18 inches (Fig. 10.3). Some bathrooms are small. This can create a problem for plumbers, especially if you are re­modeling the bathroom with new fixtures or possibly different types of

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fixtures. Getting your rough-in for the fixtures right is crucial to the job. If you install a drain for a toilet and find out when you go to set fixtures that there is inadequate space for the toilet to comply with the plumbing code, there could be a lot of work and expense re­quired to correct the situation.

When you are laying out plumbing fixtures, you should concentrate on what you are doing. Get to know your code re­quirements and check the fixture place­ment in all directions. Figure 10.4 shows how a legal layout might look. in contrast,

Figure 10.5 shows what would result in an illegal layout. Notice that the distance from the edge of the vanity is only 12 inches from the center of the toilet. To meet code, the distance must be at least 15 inches. A problem like this might be avoided by using a smaller vanity. If the potential problem is caught on paper, before pipes are installed, it is much easier and less costly to correct.

Something else to consider when set­ting fixtures is their overall alignment.

The plumbing codes not only require cer­tain defined standards, they also deal with topics such as workmanship. This means that a job could be rejected if the fixtures are installed in a sloppy manner. Figure 10.6 shows a toilet where the flush tank is not installed with equal distance from the

back wall. A proper installation would have the toilet tank set evenly, with equal distance from the back wall, as is indicated in Figure 10.7.

Dormitories require the use of one laundry tray for each 50 people and one slop sink for each 100 people. However, washing machines can be used in lieu of laundry trays. This information is found in Figure 9.14 and Figure 9.2. It is also required that dormitories which are for the exclusive use of one sex or the other shall have double the number of fixtures listed under the gender-spe­cific restrooms in the table. There are also rulings in Figure 9.14 pertaining to bathtubs and showers. You will find that sizing dormitories is not difficult, but that it does involve some rules that we have not previously used.

GATHERING PLACES

Gathering places, such as churches, theaters, auditoriums, and similar places can be sized for plumbing fixtures by using the information in Figure 9.15. This reference table is straightforward and holds no surprises. If at any time you are not sure how to title a building’s classification, check with your local code enforcement office. Remember also to verify local standards for sizing requirements. Given the proper information from your local code, you should have no trouble determining the minimum fixture requirements for buildings.

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Heavy manufac­turing, l() ware­houses1,1 foun­dries, and similar establishments12-14 Occupant content per shift, sub­stantiated by owner. Also see 407.3.2 Persons (total) Male Female Persons (total) Male Female One drinking fountain for 1-10 11-25 26-50 51-75 76-100 For each addi­tional 60 per- 1 2 3 4 5 1 1 1 1 1 1-15 16-35 36-60 61-90 91-125 For each addi­tional 100 1 2 3 4 5 і і і і і each 75 persons. One shower for each 15 per­sons exposed to excessive heat or to skin contami­nation with poisonous, infectious, or irritating material. sons over 100, persons over add 1 0.17 125 add 1 O. l7

FIGURE 9.12 ■ Minimum fixtures for heavy manufacturing. (Courtesy of Standard Plumbing Code)

Dormitories’5 50 sq ft per Persons (total) Male16 Female16 Persons (total) Male Female Washing machines may be person (calculated on sleeping area only) 1-10 11-30 31-100 For each additional 50 persons over 100, add 1 1 3 1 1 2 4 1 1-12 13-30 For each additional 30 persons over 30 add 1 2 1 1 2 1 used in lieu of laundry tubs.15 One shower for each 8 persons. In women’s dorms add tubs in the ratio 1 for each 30 females. Over 150 persons add 1 shower for each 20 persons.

FIGURE 9.14 ■ Minimum fixtures for dormitories. (Courtesy of Standard Plumbing Code)

Theaters, auditoriums, churches, waiting rooms at transportation terminals and stations		Drinking fountains Persons Fixtures 1-100 1 101-350 2 Over 350 add one fixture for each 400.
FIGURE 9.15 ■ Minimum fixtures for gathering places. (Courtesy of Standard Plumbing Code)

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Warehouses, foundries, manufacturing buildings, and similar buildings have some special requirements. For example, a shower must be provided for each 15 people who may be exposed to excessive heat or to skin contamination with poisonous, infectious, or irritating material. When you look at the table in Figure 9.12 you will see a number of numbers at the topic headings. Refer back to Figure 9.2 for an understanding of the special notes. An example of such a note is number 14 in the list of Figure 9.2. It says that one lavatory must be supplied for every 15 people who may have exposure to skin contamina­tion with poisonous, infectious, or irritating materials. Refer all of the special notes before you begin figuring your fixture needs.

LIGHT MANUFACTURING

Buildings used for light manufacturing are affected by the special notes listed in Figure 9.2. Pay attention to all the note references in the table labeled as Figure 9.13. You will see that the sizing table is like the others that we have been using and is just as easy to negotiate.

Hair shops, like beauty salons and barber shops are required to have a drink­ing fountain and a service or utility sink. Figure 9.11 shows the basic require­ments for fixtures in these types of buildings. it is worth noting that only one lavatory is required for each bathroom, regardless of the occupancy load. it is also possible that beauty shops and barber shops might be required to main­tain only one restroom for occupants.

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Building or occupancy2 Occupant content2 Water closets3 Lavatories4 Bathtubs, showers and miscellaneous fixtures Clubs, lounges, and 40 sq ft per Persons (total) Male Female Persons (total) Male Female Comply with board of restaurants with club person 1-50 2 2 1-150 1 1 health requirements or lounge6 51-100 3 3 151-200 2 2 101-300 4 4 201-400 3 3 For each For each additional 200 additional 200 persons over persons over 300, add 1 2 400, add 1 1

FIGURE 9.9 ■ Minimum fixtures for clubs and lounges. (Courtesy of Standard Plumbing Code)

FIGURE 9.10 ■ Minimum fixtures for do-it-yourself laundries. (Courtesy of Standard Plumbing Code)

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Beauty shops One drinking fountain and and 50 sq ft Persons Persons one service or other barber shops6 per person (total) Male Female (total) Male Female utility sink. 1-35 1 1 1-75 1 і 36-75 2 2

FIGURE 9.11 ■ Minimum fixtures for hair-care establishments. (Courtesy of Standard Plumbing Code)

When you are dealing with clubs and lounges, you must pay attention to Board of Health requirements. Remember that if a restaurant will be serving alcoholic beverages, the building will be treated as a club or lounge for fixture require­ments. I should also point out that the tables we are using are from the Standard Plumbing Code. Local codes vary, so don’t use these tables for your actual work. I’m providing the tables for the sake of examples, not as the final word.

I’m not going to continue doing routine examples of table use. You should understand the basic concepts now. However, I will touch on the remaining categories and provide you with sample tables for determining minimum plumbing fixtures. Figure 9.9 is a table set up for clubs and lounges. There is nothing unusual about the table, so apply the same principles that we have been working with.

LAUNDRIES

Do-it-yourself laundries are required to have at least one drinking fountain and one service sink. Figure 9.10 will give you the basics for sizing fixture re­quirements of do-it-yourself laundries. Notice that this type of laundry might be allowed to operate with a single bathroom.

Offices and public buildings may be allowed to have only one bathroom, sub­ject to the size and use of the building. Refer to Figure 9.2, line number 6, for a complete description of possible options in using a single bathroom. The table in Figure 9.8 shows you sizing information for offices and public build­ings where multiple bathrooms are used. Feel up to another sizing example? Well, let’s try a couple with the table in Figure 9.8.

FIGURE 9.7 ■ Minimum fixtures for elementary and secondary schools. (Courtesy of Standard Plumbing Code)

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Office6 and 100 sq ft Drinking fountains public buildings per person Persons (total) Male Female Persons (total) Male Female Persons Fixtures 1-15 1 1 1-15 1 1 1-100 1 16-35 1 2 16-35 1 2 101-250 2 36-55 2 2 36-60 2 2 251-500 3 56-100 2 3 61-125 2 3 Not less than one 101-150 3 4 For each fixture each floor For each additional 120 subject to access. additional 100 persons over persons over 125 add 1 1.57 150 add 1 1.57

FIGURE 9.8 ■ Minimum fixtures for offices and public buildings. (Courtesy of Standard Plumbing Code)

Okay, assume that the public building we are working with will be rated for 75 people. What are the fixture requirements? We will need two toilets in the male restroom and three in the female restroom. How many lavatories are required? Two lavatories are needed in the male restroom and three are re­quired in the female restroom. One drinking fountain is required, but others may be required if the building has more than one floor level, since a fountain is required on each floor of the building. That wasn’t too hard, was it? Now let’s try an example with a larger occupancy load.

In this example, assume that there will be 250 occupants. The amount of water closets needed in the male restroom is four. How many are need in the female restroom? Looks like 5V2 toilets, right? Well, it is, but you have to round up to the next nearest whole number. In other words, you would need six toilets in the female restroom. What are the needs for lavatories? The male restroom requires four lavatories, and the female lavatory need is six. How many drinking fountains are needed in a building that has only a single floor? Three fountains are required.

Day-care centers, pre-schools, and nursery schools all fall under the same classification when computing minimum needs for plumbing fixtures. Figure 9.6 shows you the formulas for figuring the number of fixtures needed. It’s a simple table. Basically, you supply one toilet and one lavatory for each 15 oc­cupants of the building. If the school will have 30 occupants, you must install two toilets and two lavatories. When 45 people will be in the school, you need three toilets and three lavatories. This is one of the easiest sizing exer­cises going.

ELEMENTARY AND SECONDARY SCHOOLS

Requirements for elementary and secondary schools are a bit more complex than those applying to pre-schools. Even so, the process of sizing the fixture needs is not difficult. Look at the table in Figure 9.7. Notice that the table is very similar to the ones we have been using. An equal number of toilets and lavato­ries is required in both male and female restrooms. One drinking fountain is re­quired for every three classrooms in the school. It is also a requirement that a drinking fountain be located on each floor of the building. All you have to do in order to figure fixtures for a school is look at the number of occupants and reference it next to the number of fixtures. For example, if you have 98 occu­pants, you need three toilets and two lavatories in each bathroom.

We’ve been dealing with commercial-type space, but let’s switch over to houses. There are times when plumbers are the ones who must figure the min­imum requirements for houses. This is especially true in very rural areas. Fig­ure 9.5 provides the information needed to compute the fixture requirements for a typical, single-family home. The same table can be used to figure the fix­ture requirements for an apartment building. Check back to Figure 9.2 for ex­planations of the numbers noted in the headings of the table. There is no big secret to this table. Each home is required to have a minimum of one toilet, one lavatory, one bathing unit, one kitchen sink, and one connection for a washing machine.

if you look at the table closely, you will see that the basic minimums are required for each dwelling or dwelling unit. This means that each apartment

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40 sq ft Restaurants617 per person Persons (total) Male Female 1-50 1 1 51-100 2 2 101-200 3 3 201-300 4 4 For each additional 200 persons over 300 add 1 2

Persons (total) Male Female Comply with board of health requirements 1-150 1 1 151-200 2 2 201-400 3 3 For each additional 200 persons over 400 add 1 1

FIGURE 9.4 ■ Minimum fixtures for restaurants. (Courtesy of Standard Plumbing Code)

FIGURE 9.5 ■ Minimum fixtures for homes and apartments. (Courtesy of Standard Plumbing Code)

in a building must be equipped with the same minimum requirements that would be found in a home. Of course, local codes may offer a different ruling, so always check your local code requirements before designing or installing plumbing systems.