- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 24 Mar 2021
Soil vent pipe
A soil vent pipe (SVP), also known as a soil stack pipe, drain-waste-vent or ventilated discharge pipe, is typically a vertical pipe that removes sewage and greywater from a building. It is often attached to the exterior of a building (although it may be fitted internally) and connects the subterranean drainage system to a point just above the level of the roof gutter.
Soil vent pipes allow the removal of waste from toilets, showers, baths and sinks, while also allowing odours to be released above the building, via a stack vent, at a level that will not cause a nuisance. The pipe’s vents also allow air into the internal drainage system so as to facilitate the process of aerobic sewage digestion, preventing a siphoning affect from occurring, and allowing free flow by gravity.
SVPs must maintain sufficient downward slope along their length to keep liquids and entrained solids flowing freely towards the drain. If a downward slope is not possible, a collection pit with a ‘sewage ejector’ pump can be installed.
Approved document H: Drainage and waste disposal requires that the foot of a discharge stack should have as large a radius as possible, and not less than 200 mm at the centre line. Offsets should be avoided in the wet section of the stack. Ventilating pipes should finish at least 900 mm above any opening within 3 m and should be finished with a wire cage or other perforated cover.
 Related articles on Designing Buildings Wiki
Featured articles and news
TASC/CIOB study looks at post-pandemic struggles and trends.
The Government announces recalibrated goals.
ECA proposes strategies for the present and the future.
Paul Morrell to lead independent review of the construction products testing regime.
Standard will help employers foster wellbeing and manage psychosocial risks.
Global fire standards for safety of people and property.
An introduction to the 5 core principles of lean.
Can the profession use its skills to save the world from climate change?
How faulty science resulted in sanitation reform.
Improving facilities, accessibility and overall appearance.
Free download of TG 12/2021 available.
TESP works with The Youth Group to form skill sharing network.
Big tech collaborates on platform for the built environment.
Letter signed by 21 organisations sent to MHCLG.
Click the button to subscribe.