Mechanical cleaning

What it attempts to do

Restore flow by removing material from inside the line using equipment fed in from an access point.

When contractors may discuss it

These are circumstances in which the approach comes up, not a checklist that makes it correct. There is no situation in which one method is universally right.

• when flow is restricted and the line has not been cleared recently
• as a first step before an inspection, so the camera sees the line rather than its contents
• as a recurring measure where a line has a known history

What has to be known before applicability can be judged

If a proposal for this work is priced without these, it is priced against assumptions. That is not necessarily wrong — but the assumptions should be written down.

• which access point is available and where it reaches
• whether the line has been cleaned before and how recently
• whether an inspection has ever followed a cleaning

Access and site considerations

• requires a usable access point
• equipment needs a route to that access point

What to clarify in a proposal for this work

These are the details that most often differ between two proposals for what sounds like the same job.

• which access point will be used and how far the equipment will reach
• whether a camera inspection is included, and whether before or after
• what happens if the line cannot be cleared
• whether the price changes if a second visit is needed

What to keep afterwards

• the invoice, including method and reach
• any observation recorded at the time
• footage, if an inspection was included

Alternatives worth asking about

Asking why one approach is proposed rather than another is a reasonable question, and the answer tells you what the contractor believes about your line.