FAQs

Question: Please clarify if clay pipes can be used for above ground installation and use and can be produced on in small diameters, which would be required for waste pipes, fittings and traps for sinks?

Answer: They can be- eg socketed 75mm and 100mm pipes are used in Malta and are connected with a Cement Mortar Joint, although smaller diameter pipes than this are not known. One of our members WT Knowles still manufactures pipes and fittings for Cement Mortar jointing. Modern flexible jointed systems such as are made by Hepworth or Naylor are not recommended for above ground use; the jointing elements (couplers or Band Seals) for plain ended pipes will deteriorate over time if exposed to UV.

Question: Where can you get a base for a concrete manhole which is being used as part of a clay sewerage system?

Answer: It is recommended that you cast your own concrete base and then set pipes and rings on that.

Question: Is it normal to have internal crack line after we hunched the laid VC pipe with concrete?

Answer: No, it is not.

Question: Why choose Clay Drainage Pipes?

Answer: Clay pipes have superior longevity, excellent chemical resistance and are environmentally friendly, having low embodied energy.

Question: Are clay pipes good?

Answer: Clay pipes have superior longevity, excellent chemical resistance and are environmentally friendly, having low embodied energy

Question: Which pipe is best for underground drainage?

Answer: Clay pipes have superior longevity, excellent chemical resistance and are environmentally friendly, having low embodied energy

Question: How do you clean clay pipes?

Answer: Clay pipes can be cleaned with traditional drain rods, or using water jetting methods. Clay is highly resistant to damage, allowing higher jetting pressures to be used than with other materials.

Question: How long do clay pipes last?

Answer: For design purposes, clay pipes have indefinite life defined as 100 year+

Question: Why specify Clay?

Answer: Clay pipes have superior longevity, excellent chemical resistance and are environmentally friendly, having low embodied energy

Question: How do you design a drainage system

Answer: Guidance is available on the CPDA website in the design tab. There is information on layouts, structural and hydraulic design. Further guidance is available in the building regulations approved document H, and supporting national standards.

Question: What size are clay drainage pipes?

Answer: The most common UK sizes of clay pipe are internal diameters 100, 150, 225 & 300mm, although other sizes including larger diameters and continental European sizes 200 & 250 are widely available

Question: How often should you have your sewer line cleaned?

Answer: Sewers laid at shallow gradients, with low flow rates can be susceptable to buildup and blockages, regardless of pipe material. A preventitive measure would be to have a sewer line cleaned every 18-22 months.

Question: What is the best pipe to use for drainage?

Answer: Clay pipes have superior longevity, excellent chemical resistance and are environmentally friendly, having low embodied energy

Question: What type of pipe is used for drains waste and vents?

Answer: Most modern drains waste vent systems are manufactured from plastic. These would connect into a clay pipe sewer at ground level.