Pipe materials and why they matter

Sewer laterals have been built from a range of materials over the last century and more. Which one you have affects how the line behaves, what an inspection shows, and which methods a contractor will raise.

This page does not rank materials, and it does not tell you what yours is. What it does is explain why the question keeps coming up and what turns an assumption into knowledge.

What this page cannot establish

this page cannot tell you what your line is made of
material cannot be established from the age of a house alone
material does not establish condition — pipes of every material exist in every condition
no material is presented here as good or bad

Why material comes up in a proposal

Some methods work with the existing pipe as a host and depend on its condition and geometry. Others replace it entirely and depend more on the ground around it. A contractor proposing either has made an assumption about what is down there, and the price reflects that assumption.

When the assumption turns out to be wrong once work begins, the result is a change order. That is the practical reason to ask how material was established before signing, rather than after.

How material actually becomes known

a camera inspection, where the interior is visible enough to characterise
excavation, which gives a direct view of a section
a connection or permit record held by the operating authority
documentation from prior work on the property

Ways material is guessed rather than known

None of these is worthless as a starting point. None of them is a finding, and none should be priced against without being labelled as an assumption.

inferring from the age of the house
inferring from what is typical in the neighbourhood
inferring from what a previous owner said
inferring from what the interior plumbing is made of

Questions about material

What material does this proposal assume, and how was that established?
If it was not observed, what happens to the price if it turns out to be something else?
Does the proposed method depend on the material, and how?
Is the whole run assumed to be the same material?

What would change the answer

to know your own material: an inspection, an excavation, a connection record, or documentation of prior work

What to do next

Material is one of the most common assumptions priced into a proposal, and assumptions are where change orders come from.

Ask how material was established in your proposal

If your situation is different

You want to know how material gets established: What a camera inspection can and cannot show

Exclusions and assumptions
Material assumptions drive change orders.
Trenchless and excavation
Which methods are discussed depends partly on the host pipe.