At W T Knowles, we pride ourselves on the wide range of clay drainage pipes, fittings and drainage accessories, manufactured and supplied from the family owned West Yorkshire factory for over 100 years. W T Knowles is the only manufacturer of traditional salt-glazed clay products which is extensively specified for its durability and eco-friendly properties, as it is unaffected by most chemicals and can last for hundreds of years when properly maintained. We supply an extensive range of Clay Drainage Pipes, Channels, Channel Fittings, Gullies and Accessories to assist the drainage designer, contractor and site owner in effective drainage and flooding control. Products are supplied into a variety of market sectors including Housing, Land and Field Drainage, Agriculture, Construction, Roads, Pathways and Parks as well as Sports facilities drainage. W T Knowles is a manufacturer an extensive range of clay products for sale through Builders Merchants.The company’s focus is on supplying high quality clay drainage products supported by reliable, short delivery. Please take some time to explore the website but if this doesn’t answer all of your questions then please call us on 01422 372833. Clay is an extremely strong and environmentally friendly product which does not corrode under normal use and can offer cost savings due to the reduction in trench depth and bedding material. Clay pipes have been used for centuries, are extremely resilient, resistant to rust, corrosion and are fire-proof.