Overview

The Holman DWV Plain Vent Cowl is the fitting that sits on top of a 50mm DWV vent pipe. It keeps vermin from entering the pipe and stops attic insulation from falling down into it, while still letting the vent system breathe. It is part of the Holman DWV Pipe Systems range, made for drainage and venting installations.

The cowl fits 50mm PVC pipes and is used in conjunction with an air admittance valve where one is fitted. It is a simple push or solvent-weld fitting with a smooth, corrosion-free PVC surface, and it is grey to match the standard DWV pipework.

Key Features

• Fits the top of a 50mm DWV vent pipe
• Deters vermin from entering the pipe
• Stops attic insulation from falling into the pipe
• Smooth, corrosion-free and tough PVC surface
• Used in conjunction with an air admittance valve
• Easy to install

Specifications

• Model: DWV PVC Vent Cowl 50/40mm Plain
• Size: 50mm nominal
• Material: poly vinyl chloride (PVC)
• Colour: grey
• Standard: AS/NZS 1260

Applications

• Topping a DWV vent pipe through the roof
• Drainage vent systems in residential buildings
• Vent pipes in commercial plumbing
• Any 50mm DWV vent pipe that needs vermin protection

What You Need to Complete the Job

Fit the cowl to the top of the 50mm vent pipe after the pipe is run and secured. Where the pipe passes through the roof, weather the penetration first with a DWV Weathering Apron, then top the pipe with the cowl. It can be used alongside the rest of the DWV fittings in the PVC Fittings range. More concreting and plumbing supplies are in the Concreting range.

Frequently Asked Questions

Why do I need a vent cowl on a DWV pipe?

The cowl keeps the vent pipe open and clear. Without it, birds, rodents and insects can nest in the pipe, and insulation or debris from the roof space can fall down and block the vent. The cowl stops that while still letting the pipe draw air, which is what the drainage system needs to work.

Does this cowl fit a 40mm pipe as well?

The cowl is listed as a 50/40mm fitting, sized for the standard 50mm DWV vent pipe range. If you are venting a smaller 40mm pipe, check the actual socket fit before ordering, because the DWV range is built around 50mm pipe for vent applications.

How is it installed?

It is easy to install. The cowl is fitted to the top of the 50mm vent pipe, and it can be solvent welded or set in place depending on the system. It is used in conjunction with an air admittance valve where the venting design calls for one.

Is it AS/NZS compliant?

Yes. The cowl carries a WaterMark certificate and complies with AS/NZS 1260 for DWV pipe systems. It is made from quality PVC with a smooth, corrosion-free surface, and it is designed for the Holman DWV range.