Components, systems and materials › Building components › Shaft and sleeve (MEP-civil interface)
Shaft and sleeve (MEP-civil interface)
What it is
Shafts and sleeves are the planned openings and conduits in slabs, beams and walls through which pipes, ducts and cables pass between floors and rooms.
Where it is used
All buildings with plumbing, drainage, electrical, fire fighting, gas and air-conditioning services; also tunnels and stations.
How it works
Openings formed before concreting avoid later core-cutting that can cut reinforcement and weaken slabs and beams. Sleeves leave a clear annular space so pipes can move and be replaced. After services are installed, the gap is sealed against water, smoke and fire so the floor or wall keeps its fire rating.
Types
- Vertical service shafts with access doors
- sleeves through slabs, beams and walls
- puddle-flange sleeves in water-retaining walls and basements
- cast-in channels and inserts for supports
Materials
PVC, HDPE, steel or GI sleeves; puddle flanges; intumescent collars, fire-rated sealants and boards; shaft doors.
Service and structural drawings are coordinated so that openings avoid columns, beam ends and high-shear zones. Large openings in slabs need trimmer bars and sometimes beams. Sleeves through beams stay in the middle third of depth and are limited in size. Shafts are sized for future expansion and maintenance access.
Installation and QA steps
- Hold a coordination review of combined drawings before each pour.
- Fix and brace sleeves and boxes in the formwork with trimmer bars.
- Check positions again just before concreting.
- Install services and seal the annular gaps.
- Fit fire-stop systems tested for the required rating and record them.
- Core-cutting through reinforcement after casting
- missing or untested fire stopping
- leaks around sleeves in wet areas and basements
- shafts too small for maintenance
Codes cited
- National Building Code of India 2016 (India): Model code for buildings: planning, structural design, fire, construction practice and safety, building services.
- NBC 2016 Part 9 (Plumbing Services) (India): Water supply, drainage, sanitation and gas supply within buildings.
Cited by number only. We do not reproduce code text, tables or figures.
Related
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