Which Sewer Pipe is best – PVC or Clay?

Which Sewer Pipe is best – PVC or Clay?

PVC sewer pipe is now the most widely used drainage system for housing and light commercial applications and serves as an excellent alternative to clay. The UK Government recently set a target of a million new homes across the UK by 2020 and with a rush to build these homes, the demand for PVC sewer pipes is set to rise. But which pipe is best – clay or PVC?

This is a question we’re frequently asked by our customers. We’ve detailed below our thoughts.

Option 1: Clay Pipe 

Many older properties still use clay or cast iron sewer pipe, and clay sewer pipe is still laid today. Here are just some of the benefits to using clay pipe:

  • It’s inert, which makes it highly resistant to chemical degradation
  • High longevity (if the pipe is not damaged)
  • Good structural integrity, which prevents deflecting or flattening under load

Clay pipe is becoming more and more outdated though. Whilst clay is still a good choice, there are a few downsides:

  • More expensive than alternative products
  • More costly should the pipe fail prematurely and require replacement
  • Heavy & hard to cut
  • Roots attach to the porous surface causing damage to the pipe
  • Susceptible to breakage and cracking
  • Susceptible to clogging

However, if an older sewer pipe is still carrying waste with no leakage, there is no reason to replace it.

Option 2: PVC Pipe

Many builders and developers are now opting for PVC sewer pipe for its superior properties. The main benefits of PVC sewer pipe include:

  • Lightweight, making it easy to handle when installing
  • Strong, which minimises cracking and breakage
  • Flexible, which minimises potential damage
  • Long-lasting with less need for replacement and repair

Our Sales Director, Luke Beer states: “PVC sewer pipes feature a smooth interior providing an excellent carrying capacity of solid waste matter. The smooth exteriors also help resist root anchorage, making it a great substitute for clay pipes. It’s also cheaper.”

Other points to consider…

After establishing whether a PVC or clay sewer pipe is best, there are a few other things you’ll need to think about to ensure you get the most out of your sewer pipes:

What size sewer pipes do I need?

At Cotterill Civils, we supply UPVC pipe in a range of diameters, including 110mm and 160mm and in 3mtr and 6mtr lengths. The right size depends on your system but, as a rule of thumb, we recommend larger diameter sewer pipes for heavy-duty applications.

If you’re unsure which size you need, feel free to get in touch with us on 0121 351 3230 and we’ll do everything we can to guide you in selecting the best one.

What fall should sewer pipes have?

According to plumbing code, all clay and PVC drain pipes need to be laid at an adequate gradient/fall. They must be sloped a minimum of ¼ inch per foot, and a maximum of 3 inches per foot.

Anything less will cause drains to clog, and a slope that’s too steep will cause solids to slow down and become stranded, resulting in blockages.

How to unblock a sewer pipe?

Sewer problems are a common issue for homes and businesses all over the UK. A damaged, blocked or clogged clay or PVC pipe can prevent toilets from flushing properly – causing sewage material to overspill or flood.

The best way to unblock pipes is to contact an experienced plumber. They’ll have the tools and expertise to diagnose the root cause of the problem before outlining the best solution to remove the blockage and restore normal function. If you’re looking to avoid additional costs and make life easier, our inspection chambers are ideal. They enable your drains to be regularly cleaned – preventing the formation of blockages.

How to insulate sewer pipes?

Insulation is ideal for PVC water pipes in cooler regions (to prevent frozen pipes and cracking) and can reduce the sound of running water where pipes run close to living areas.

The good news is it’s easy to do and you only need a tape measure, fibreglass wall insulation, utility knife, duct tape, plastic sheeting and gloves.

4 simple steps to insulate pipes:

  1. Measure the length of the run of the sewer pipe and cut the insulation material to match.
  2. Lay a strip of the insulation along the top of the sewer pipe.
  3. Pull the edges of the insulation around the pipe, so they overlap and tack them down using duct tape. When the pipe is completely covered, run a piece of tape along the length of the seam/edge of the insulation.
  4. To prevent moisture build-up, wrap the insulation with plastic sheeting. Then use tape to seal the edges.

How to repair sewer pipes

A broken UPVC pipe is easier to replace than a clay pipe but both can cause serious damage if left untreated. Spotting problems early can prevent severe damage and help you to get the most out of your sewer pipe system. Be on the lookout for mould growth, cracks in the foundations or sinkholes.

Depending on the extent of the damage, it might be easier to buy a new PVC sewer pipe, but relax, we supply an extensive range at Cotterill Civils.

Where to go for advice?

We’re one of the UK’s leading providers of PVC Sewer Pipe and can provide you with a solution to meet your specific needs and budget. We can provide you with expert advice on the different options available to you, including couplers, bends, junctions, screwed access caps, level invert reducers, inlet bottle gullies, traps, plain ended solid pipe, draw rope and sealed aluminium rodding eye.

We also price match our sewer products to give you the best prices.

Please get in contact on 0121 351 3230 or visit our dedicated underground sewer pipe page to find out more.