When can a stub stack be used?
An unventilated stub stack terminated with an access fitting may be used to connect a group of ground floor appliances to the building drain provided the vertical drop to the invert level of the drain does not exceed 1.5m from a WC and 2.5m from a waste appliance.
What is a stub stack drainage?
A stub stack is a cut-off version of an SVP, which is fitted with an air admittance valve to prevent foul smells. The stub stack should still be a 100mm diameter pipe. Rules on the use of stub stacks are commonly forgotten.
Where should an air admittance be installed?
Air Admittance Valves must be installed on a soil pipe at least 200mm above the highest water entry point on the system – that is the highest point that water can normally reach in a soil pipe. For aesthetic purposes though they are usually installed in the loft or in a duct or cupboard.
Can you box in an air admittance valve?
Where an AAV is enclosed in a boxing the boxing should be ventilated. The use of ventilation grilles, discreet gaps around the boxing or ventilation of the boxing into a ventilated roof void are some acceptable methods of providing ventilation.
Can a toilet soil stack have bends?
as long as it has an adequate fall on it to the soil stack.
Does kitchen sink drain need to be vented?
A kitchen sink drain needs to be vented so as to prevent clogging and ensure free flow of water and liquids from the sink. also, venting a kitchen sink allows air to enter behind the water that is flowing out. Vented drains also help do away with odors that come from the kitchen sink.
How high should an AAV be?
The Sure-Vent® AAV must be located a minimum of 4 inches above the horizontal branch drain and 6 inches above any insulation material and within 15 degrees of vertical.
How much air does an AAV need?
In selecting an AAV, the minimum airflow rate is eight times the total flow rate. Example: Bath (DU = 1.3), shower without a plug (DU = 0.4), WC (DU = 1.2 to 1.7) and wash basin (DU = 0.3). Sum of discharge units = 1.3 + 0.4 + 1.7 + 0.3 = 3.7 l/s.
Can you use an AAV to vent a toilet?
Don’t worry if you do not have a vent pipe in your house, or if it is blocked and you can’t fix it. Instead of thinking about massive construction projects, you can use an Air Admittance Valve, well-known as a cheater vent. Atmospheric pressure goes through the valve and has the same effect as in the classical venting.
Do air admittance valves smell?
air admittance valves only let air in,that is if they are installed correctly,but they can not do anything about back pressure in system ,this can push smells through traps and into the room.it could be syphonage of one or more traps,due to poor pipework installation,but is more likely to be shower wastes that are the …
Does a vent stack have to go straight up?
Vent pipes must be installed so they stay dry. This means that they should emerge from the top of the drainpipe, either straight vertically or at no less than a 45-degree angle from horizontal, so that water cannot back up into them.