Stainless Steel Vent Shafts, Built to Your Drawings
Sewer vent shafts let air in and out of the wastewater network. When a development, a new sewer main or an ageing asset needs a vent shaft made, replaced or moved, Grana Works gives you one point of contact for the steelwork: shop fabrication, delivery to site and installation, organised through experienced specialist welding partners and managed by us.
We work for developers, civil and principal contractors, builders and the project teams delivering sewer works. Send the drawings, the site address and your program, and we will confirm the scope and quote in writing.
Vent Shaft Services
- Fabrication: stainless steel shaft sections, base plates, flanges, gussets, inspection openings and cowl fittings, made to the nominated drawings
- Supply: complete vent shafts and components delivered to site, ready to install
- Installation: setting out, lifting planned as part of the job, erecting the shaft on its footing, bolted and flanged joints, and clean-up
- Replacement: like-for-like replacement of ageing or damaged vent shafts
- Relocation or removal: where Sydney Water has assessed and accepted the change for your development
- Repairs and modifications: welding repairs to brackets, supports and components where the asset owner allows it
- Footings and civil works: excavation and concrete footings through our civil & excavation service, and non-destructive digging to locate underground services first
Recent Vent Shaft Work
Photos from recent vent shaft fabrication and installation jobs, delivered with our specialist welding partners.
Sydney Water Vent Shafts: Key Facts
These facts come from Sydney Water’s published Ventilation shafts fact sheet and its Guideline – ventilation shaft (D0002473). Always check the current documents for your job.
- Sydney Water maintains and operates about 12,500 vent shafts across Sydney, the Blue Mountains and the Illawarra.
- New vent shafts are unpainted stainless steel, between 9 and 18 metres tall and from 150 mm to 300 mm in diameter (DN150, DN225 and DN300).
- A vent shaft is placed about every 400 metres along a wastewater pipeline, often at high points, at the start and end of a line, and next to a maintenance hole.
- Shafts are bolted to a concrete block flush with the ground and need a space of about 2.5 × 2.5 metres. Building a vent shaft and maintenance hole together normally takes about three to four weeks, depending on weather and ground conditions.
- The current DTC drawings are DTC 2300 and 2301 (ventilation shaft, stainless steel, 9–18 m, DN150–DN300) and DTC 2302 (ventilation shaft replacement). Use of DTC drawings is subject to Sydney Water’s DTC terms of use.
- DTC 2300 notes that new vent shafts should be located 2 metres clear of nearby structures.
- Vents work as induct vents (fresh air in), educt vents (foul air out) or both. The wire (bird) cowl is the most common and preferred cowl; rotating cowls are used on educt vents, and forced induct (wind-vane) cowls are also accepted, with or without a flap.
Relocating or Removing a Vent Shaft for a Development
A vent shaft can’t simply be moved because it is in the way. Under Sydney Water’s guideline, a developer applies to relocate or remove a shaft, and Sydney Water assesses the change. The investigation can include continuous differential pressure monitoring in the vent shafts over about four weeks, and gas monitoring over dry-weather days. Your designer or water servicing team manages the application. Once the design is accepted, we can quote and organise the new shaft’s fabrication, supply and installation, and the removal of the old one.
How a Vent Shaft Job Runs
- 1. Enquiry – send the drawings or DTC reference, shaft height and diameter, the site address and your program
- 2. Review – we check the drawings, material, access, footing, overhead and underground services, and lifting needs
- 3. Written quote – fabrication, supply, installation and any civil works, itemised so you can compare
- 4. Fabrication – shop fabrication by our specialist partners to the nominated drawings and specification
- 5. Delivery and installation – hot-work and lift planning as the site requires, erection, bolting and clean-up
- 6. Handover – photos and the documents your job asked for at quote stage
What Affects the Price of a Vent Shaft
- Shaft height, diameter, wall thickness and stainless steel grade
- Cowl type, inspection openings, flanges and fittings
- Supply only, or supply and install
- Footing and civil works, and locating underground services
- Site access: backyards, roadsides, overhead power lines and nearby structures
- Lifting method, documentation and testing required by your specification
Materials, Welding & Quality Documents
Stainless steel grade, finish, weld procedures and any testing are set by your drawings and specification, not by us. Tell us what your job requires, for example material certificates, weld records or an inspection and test plan, when you request a quote. We will confirm what our specialist partners can provide before you commit.
Safety on Vent Shaft Jobs
Vent shaft work combines hot work, lifting long sections and working near live sewer assets. It is planned around the site’s permits, with exclusion zones during lifts and a fire watch after welding. Grana Works organises and manages the work, including through trusted specialist partners. Gaurav holds personal tickets for dogging, rigging, forklift and boom lift, along with an HR (heavy rigid) licence and crane inspection.
Often Booked Together
Areas We Serve
We organise vent shaft work across Greater Sydney, the Blue Mountains and the Illawarra from our base at 19/55 Anderson Road, Smeaton Grange, in the Macarthur region. Larger jobs further out are quoted by distance. See all service areas, our welding & fabrication page, or pipe welding in Sydney.