Why is ventilation so important ?
By Rory Macnamara
FEATURE 23
Plumbing ventilation in the system is a critical element of plumbing .
While pipes are often the reason for plumbing problems due to blockages and such , the ventilation pipe or vent stack as it is commonly known can also be the cause of problems as these can become clogged or damaged .
SANS 10400 Part P Drainage clearly provides the sizing of ventilating pipes as per table 15 – sizing of ventilation pipes .
The whole system should always be considered when assessing the problem and this includes vents . As the pipe system is designed to carry waste and water , the drainage and vents are two systems that work together .
The role of the vent pipe is two-fold in relation to AIR . As pipes allow water to flow and remove waste , the vent allows air to move odours away from the building and inhabitants , as well as allowing fresh air into the pipe system to assist in allowing water to flow smoothly through the drainpipes .
The vent pipes supply fresh air to each plumbing fixture , enabling water to move through the drainage pipes each time a toilet is flushed , or a sink is drained , or tap is turned on .
One will notice a vent pipe on top of roofs in older buildings and more recently we have adopted the smaller and shorter version . These may not be installed under a window or openings that could allow odours to enter the building .
Size of ventilating pipes .
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Basically , when a vent is blocked or damaged , negative pressure builds up in drainage pipes and the water flow is interrupted . While the household plunger may sort out the problem in the pipe , the vent may be the problem , which allows the clogging to start up again .
A Qualified plumber will take into account the whole system to resolve the issue and not a short-term solution like a plunger or drain cleaning when in fact the vent pipe may be the problem .
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Photos by Plumbing Africa Rory Macnamara
1 - 4 : Four photos showing ventlation stacks
November 2022 Volume 28 I Number 9 www . plumbingafrica . co . za