Scope
- Covers all types of pipes (supply, transport, delivery, disposal, distribution systems).
- Includes pipes laid underground, above ground, or within structures.
- Applies to pressure pipes, gravity drains, sewers, culverts, ducts, and service conduits.
- Excludes:
- Precast concrete pipes (measured in Class H)
- Pipe fittings, valves, ancillaries (measured in Class J)
- Pipe supports and brackets (measured in Class K)
1. General Principles
- Pipes are measured by length (m), number (no.), or weight (kg/tonne) depending on material.
- The rate for pipes is deemed to include:
- Supply, delivery, unloading.
- Laying in trench or above ground.
- Jointing and testing.
- Protection (e.g., coatings, linings).
- Temporary caps, plugs, and seals.
- Bedding, surround, thrust blocks, and chambers → measured separately in Class E (Earthworks) or Class G/H.
2. Sub-classifications under Class I
Pipes are grouped by material type:
I1 – Ductile Iron (DI) Pipes
- Common for water mains.
- Usually spigot and socket with push-fit or mechanical joints.
- Measured in length (m).
I2 – Cast Iron Pipes
- Older systems, drainage, gravity sewers.
- Measured in length (m).
I3 – Steel Pipes
- For high-pressure mains, oil, gas, or industrial services.
- Includes welded or flanged types.
- Measured in length (m).
I4 – Concrete Pipes (Non-precast specials)
- Large diameter in-situ cast or segmental.
- Precast (circular or box culverts) are Class H.
I5 – Vitrified Clay Pipes
- Traditional sewer pipes.
- Measured in length (m).
I6 – Plastics (uPVC, HDPE, MDPE, PP, GRP)
- Potable water, irrigation, drainage, ducts.
- Includes electrofusion, butt-fusion, or push-fit.
- Measured in length (m).
I7 – Other Pipes
- Asbestos cement (obsolete but may appear in renovations).
- Copper, lead, or specialist lined pipes (chemical plants).
- Measured in length (m) or number for special cases.
3. Measurement Rules
- Unit:
- Linear measurement along pipe centreline in metres (m).
- By number (no.) for short specials (spools, bends if classified here).
- By weight (t) for large diameter steel.
- Diameter:
- Always internal diameter (ID) unless otherwise noted.
- Joints:
- Included in pipe rate unless special (flanged, welded → still deemed included).
- Bends, junctions, tees, fittings:
- Not in Class I → measured in Class J (Pipework ancillaries).
- Testing and commissioning:
- Normally included in pipework.
- Lining/coatings:
- If integral (cement mortar lining, bitumen, epoxy, polyethylene) → included.
- If special protective wrapping (tape wrapping, PU coating) → stated in description.
4. Information to State in BOQ Description
Each pipework item must specify:
- Material (DI, steel, uPVC, GRP, clay, etc.).
- Size (ID/OD and wall thickness or class/pressure rating).
- Jointing method (push-fit, welded, flanged, mechanical).
- Special finishes (lining, coating, wrapping).
- Testing requirements (hydraulic, air, pressure).
- Laying condition (in trench, above ground, in concrete surround).
5. Example BOQ Items (Class I)
- Supply and lay ductile iron pipe, Class K9, 200 mm dia, spigot and socket, push-fit joint, laid in trench, per metre.
- Supply and lay mild steel pipe, 600 mm dia, 10 mm wall thickness, butt-welded, epoxy-lined and coated, laid above ground, per metre.
- Supply and lay HDPE pipe, PN10, 160 mm dia, with electrofusion joints, in trench, per metre.
- Supply and lay vitrified clay pipe, 300 mm dia, with flexible joints, including testing, per metre.
- Supply and lay GRP pipe, 400 mm dia, Class 12 bar pressure, rubber ring joints, in trench, per metre.
✅ Summary of Class I: Pipes
- Covers all pipe materials (DI, CI, steel, concrete, clay, uPVC, HDPE, GRP, etc.).
- Measurement is usually per metre (m) along centreline.
- Rate includes supply, laying, jointing, testing, lining, coating.
- Fittings, valves, specials → Class J.
- Supports and brackets → Class K.
