A sleeve pipe is an oversized pipe placed around a service pipe or cable, so that the service does not sit directly in the structure or in the ground. The service is protected, it can move independently of the building, and it can be replaced later without breaking out walls or floors. Related names you will meet are sleeve, liner, ducting and — for an empty sleeve waiting for a future cable — draw pipe or spare duct.
Where sleeves are used
- Through a foundation or basement wall — the most important application. The building settles, the pipe does not; without a sleeve the pipe shears off exactly where it is cast or built in
- Through floors and walls inside the building, to avoid structure borne sound and to let the pipe expand freely
- Under paving and driveways — so a cable or pipe can be pulled through later without breaking up the surface
- In the ground, as protection against digging damage and settlement loads
Rules for getting it right
- Clearance. Size the sleeve so the service can move freely and does not bind. If it binds, the structure takes the pipe with it after all
- Sealing. A sleeve through a basement wall or slab below the water table must be sealed with a purpose made link seal or puddle flange — not with mastic or expanding foam
- Fire stopping. Where the penetration crosses a fire separating element, the seal must restore the fire resistance of that element. For plastic pipes that means an intumescent collar or wrap; for metal pipes usually a tested sealing system with insulation. Always use a system whose tested configuration matches your situation
- Fall. Lay a sleeve through an external wall with a slight fall to the outside so water cannot stand against the inner face
- Draw cord. Always leave a draw cord in an empty sleeve. Without one, a long empty duct is practically worthless
- Record it. Note where the sleeves run and where the ends surface. That is five minutes at handover and a wasted day of searching later
Related terms
- Roof penetration
- Services
- Crawl space
- Fire resistance
- Compartmentation
- Movement joint
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