10.1 Cleanouts, Manholes, and Access Requirements
Key Takeaways
- IPC 708.1.1 requires cleanouts on horizontal drainage pipes and building drains at intervals of not more than 100 feet, with manholes permitted instead at intervals of not more than 400 feet.
- IPC 708.1.2 requires cleanouts on building sewers smaller than 8 inches at intervals of not more than 100 feet, and manholes on sewers 8 inches and larger within 200 feet of the building drain junction and at intervals of not more than 400 feet.
- IPC 708.1.4 requires a cleanout at a change of horizontal direction greater than 45 degrees, with one cleanout serving all such changes occurring within 40 feet of developed length.
- IPC 708.1.5 sizes cleanouts the same as the piping served, except that cleanouts for piping larger than 4 inches need not be larger than 4 inches.
- IPC 708.1.10 requires 18 inches of clearance for cleanouts on 6-inch and smaller piping and 36 inches for 8-inch and larger piping.
Where cleanouts are required
IPC 708.1 requires cleanouts for drainage piping per Sections 708.1.1 through 708.1.12. Six triggers matter most.
708.1.1 Horizontal drains and building drains
Horizontal drainage pipes in buildings shall have cleanouts located at intervals of not more than 100 feet. Building drains shall have cleanouts located at intervals of not more than 100 feet except where manholes are used instead of cleanouts, in which case manholes shall be located at intervals of not more than 400 feet.
The interval is measured from the cleanout or manhole opening, along the developed length of the piping, to the next drainage fitting providing access for cleaning, the end of the horizontal drain, or the end of the building drain.
Exception: horizontal fixture drain piping serving a nonremovable trap is not required to have a cleanout for the section between the trap and the vent connection for that trap.
708.1.2 Building sewers
| Sewer size | Requirement |
|---|---|
| Smaller than 8 inches | Cleanouts at intervals of not more than 100 feet |
| 8 inches and larger | A manhole located not more than 200 feet from the junction of the building drain and building sewer, and at intervals of not more than 400 feet |
708.1.3 Building drain and building sewer junction
The junction of the building drain and the building sewer shall be served by a cleanout that is located at the junction or within 10 feet of the developed length of piping upstream of the junction. For the requirements of this section, the removal of the water closet shall not be required to provide cleanout access.
That last sentence retires an old practice: pulling a first-floor toilet is not an acceptable substitute for a cleanout at the sewer junction.
Colorado field note (not exam-scored): Board Rule 1.2(E)(1)(mm) adds that when the cleanout is installed at the junction, it shall be an approved two-way fitting with a single riser not to exceed 4 feet in depth, or a two-riser cleanout using back-to-back combination fittings or equal, of schedule 40 material, installed and tested at underground or rough-in per Section 312.2.
708.1.4 Changes of direction
Where a horizontal drainage pipe, a building drain or a building sewer has a change of horizontal direction greater than 45 degrees, a cleanout shall be installed at the change of direction. Where more than one change of horizontal direction greater than 45 degrees occurs within 40 feet of developed length, the cleanout installed for the first change of direction shall serve all changes within that 40 feet.
The word horizontal is doing real work. A vertical change of direction — a stack landing on a building drain — is not a 708.1.4 trigger.
Cleanout size — IPC 708.1.5
Cleanouts shall be the same size as the piping served, except that cleanouts for piping larger than 4 inches need not be larger than 4 inches.
Three exceptions:
- A removable P-trap with slip or ground joint connections can serve as a cleanout for drain piping one size larger than the P-trap size.
- Cleanouts located on stacks can be one size smaller than the stack size.
- Cleanout size for cast-iron piping may follow the referenced standards for cast-iron fittings in Table 702.4.
So an 8-inch building drain gets a 4-inch cleanout, and a 6-inch stack may carry a 5-inch cleanout.
708.1.6 Cleanout equivalent: a fixture trap or a fixture with an integral trap, removable without altering concealed piping, is acceptable as a cleanout equivalent.
708.1.7 Cleanout plugs: of copper-alloy, plastic or other approved materials; borosilicate glass systems use borosilicate glass plugs; copper-alloy plugs are limited to metallic piping systems. Plugs have a raised square head, a countersunk square head or a countersunk slot head.
Access and clearance
708.1.10 Required clearance
| Piping size | Clearance from and perpendicular to the face of the opening |
|---|---|
| 6 inches and smaller | not less than 18 inches |
| 8 inches and larger | not less than 36 inches |
That clearance is the room needed to swing a cable machine or insert a rod. A cleanout 8 inches from a furnace is unusable, and unusable is non-compliant.
708.1.11 Cleanout access
Required cleanouts shall not be installed in concealed locations.
"Concealed locations" expressly include:
- inside plenums,
- within walls,
- within floor/ceiling assemblies,
- below grade, and
- in crawl spaces where the height from the crawl space floor to the nearest obstruction along the path from the crawl space opening to the cleanout is less than 24 inches.
Additional rules in the same section:
- Cleanouts with openings at a finished wall shall have the face of the opening within 1-1/2 inches of the finished wall surface.
- Cleanouts below grade shall be extended to grade level so the top of the plug is at or above grade.
- A cleanout in a floor or walkway without a trim cover shall have a countersunk plug flush with the finished surface.
708.1.11.1 requires trim covers and access doors designed for the purpose and approved, with corrosion-resistant fasteners, and prohibits covering cleanout plugs with mortar, plaster or any other permanent material.
708.1.11.2 requires ASME A112.36.2M floor cleanout assemblies where a plug must be protected from vehicular traffic loads.
Direction of cleaning and prohibited use
708.1.9 Installation arrangement: the arrangement of a cleanout shall enable cleaning of drainage piping only in the direction of drainage flow. Two exceptions: test tees serving as cleanouts, and an approved two-way cleanout installation meeting 708.1.3.
708.1.12 Prohibited use: using a threaded cleanout opening to add a fixture or to extend piping is prohibited, except where another cleanout of equal size is installed with the required access and clearance. Tapping the cleanout at the base of a stack to pick up a new floor drain destroys the access the code required there.
Manholes — IPC 708.1.8
Manholes and manhole covers shall be of an approved type. Manholes located inside of a building shall have gas-tight covers that require tools for removal.
A cleanout audit
A restaurant's underslab drainage: a 4-inch building drain runs 130 feet from the far end of the kitchen to the foundation, with two 90-degree horizontal offsets 22 feet apart, and connects to a 6-inch building sewer that runs 260 feet to the main.
| Requirement | Applies? |
|---|---|
| Cleanouts every 100 feet on the 130-foot building drain | Yes — at least one intermediate cleanout, 708.1.1 |
| Cleanout at each 90-degree horizontal offset | One cleanout serves both, because the two changes occur within 40 feet of developed length, 708.1.4 |
| Cleanout at the building drain / building sewer junction | Yes, at the junction or within 10 feet upstream, 708.1.3 |
| Cleanouts every 100 feet on the 260-foot, 6-inch building sewer | Yes — the sewer is smaller than 8 inches, so the 100-foot rule applies, not the manhole rule, 708.1.2 |
| Cleanout size | 4 inches for the 4-inch drain; for the 6-inch sewer, not required to exceed 4 inches, 708.1.5 |
| Clearance at each cleanout | 18 inches, since all piping is 6 inches or smaller, 708.1.10 |
| Below-grade cleanouts | Must be extended to grade, 708.1.11 |
| Grease interceptor upstream slope | 1/4 inch per foot on the kitchen line feeding the interceptor, 704.1 |
A 6-inch building sewer runs 260 feet from the building to the public sewer. What does IPC 708.1.2 require?
What size cleanout is required on a 6-inch building drain?
A horizontal building drain has three changes of horizontal direction greater than 45 degrees within 35 feet of developed length. How many cleanouts are required for those changes?
What clearance does IPC 708.1.10 require in front of a cleanout on a 4-inch drain?