Building components · Service Zones & Penetrations
Pipe Sleeve
Explains the sleeve as the lining that keeps a crossing service and the surrounding fabric independent of one another.
Educational reference entry. What this element has to do, and whether any particular arrangement of it is adequate, depends on the whole assembly, the loading, the exposure, local requirements, the manufacturer's instructions and qualified professional design.
Overview
What a sleeve is
A sleeve is a lining set through the thickness of a wall, floor or slab before that element is complete, so that the pipe passing through touches the sleeve rather than the structure, and so that the hole through the element has a formed and terminated edge, which is the only thing the sleeve itself closes.
The point of the separation is that pipes and structures do not behave alike. A pipe lengthens and shortens with what it carries, it passes on vibration, and it may have to be withdrawn; a structure moves for reasons of its own. A pipe cast directly into an element is restrained by it, and the sleeve is what keeps the two independent while still leaving a defined opening through the element.
Boundaries
How it differs from nearby elements
The distinctions that keep this entry from being a restatement of its neighbours.
- It is not a service penetration. The penetration is the position at which a service crosses the element; the sleeve is a thing built into that position, and a crossing can be made without one.
- It is not the seal around a pipe. The annular space between sleeve and pipe still has to be closed for whatever the element was relied on to do — the sleeve creates that space rather than closing it, which is why a sleeve alone leaves an open path through the element.
- It is not a duct or a conduit. Those carry a service along its route; a sleeve is no longer than the element is thick, carries nothing, and stops at the two faces.
Terminology
Common names and aliases
These names describe the same element. The library keeps one entry per component so that a trade term or a regional name never becomes a second, thinner page.
- sleeve
- cast-in sleeve
- wall sleeve
Dependencies
What it depends on
What has to be right elsewhere for this element to do its job.
- Being placed before the element is completed, since a sleeve is a cast-in or built-in provision rather than something introduced to a finished element.
- Standing clear of the pipe all round, because a sleeve in contact with the pipe has separated nothing.
- How the annular space between sleeve and pipe is closed, which is a separate provision governed by what the element is relied on to do.
- Whether it projects beyond the finished surface, which is what decides whether water lying on a floor can reach the opening.
Considerations
Topics that genuinely apply here
Subjects worth discussing about this element. These are discussion topics, never measured values, ratings or performance claims.
The reason a sleeve exists is that the pipe and the element move independently, and the sleeve is what allows both to do so without one loading the other.
Through a floor, the crossing sits at the level water reaches first, and whether the sleeve stands above the finished surface decides whether that water travels through the element.
A pipe in direct contact with a structure passes its noise into the building through that contact; the separation a sleeve provides removes the contact, though what closes the space around it matters just as much.
The annular space in a sleeve is an open path through the element until it is closed, and where the element is relied on by the fire strategy what closes it is determined by qualified designers.
Materials
Commonly formed from
Material families this element is commonly realised in. This states common practice only — it is not a statement that any of these materials suits this component in a particular building, which depends on the whole assembly and on qualified review.
Assemblies
Building systems this element is met in
The role this component fills inside each assembly. A role describes what the element does there — it is not a statement that this component suits that system in any particular building.
Clarifications
Commonly misunderstood
- That a sleeve seals a crossing. It does the opposite: it deliberately creates a gap, and the gap is closed by something else entirely.
- That a sleeve can be added later. It is provision made while the element is being formed, and a hole cut into a finished element and lined afterwards is a different and far less controlled thing.
Conversations
Questions for qualified professionals
Questions worth asking someone with the project in front of them. This page cannot answer them.
- Is a sleeve provided at this crossing, and was it cast or built in as the element was formed?
- How is the annular space between sleeve and pipe closed, and what was that closure chosen to achieve?
- Does the sleeve project above the finished floor surface, and what governed that decision?
- How does the arrangement allow the pipe to move relative to the element around it?
Go deeper
Related Build Design Hub guides
Planning guidance behind the decisions this element involves.
Preparation
Related planning checklists
Owner-side preparation before the conversation where this element comes up.
What this entry does not do
- This entry describes a position and its purpose. It states no sleeve size, projection, clearance, closure material, fire rating or period.
- What is required around a pipe crossing a structural or fire-separating element is determined by qualified designers and by local requirements.
Service Zones & Penetrations
The voids, shafts, chases and openings left in the fabric so services can pass through it and be reached again afterwards.
Browse all service zones & penetrations entries →