Why professional drain cleaning saves money

A bottle of drain cleaner is about eight dollars. Clearing the drain properly is $99. The bottle looks like the obvious choice right up until you count what happens next.

What chemical cleaner actually does

Most consumer drain cleaners work by generating heat and dissolving organic matter. In a line that is fully blocked, the product sits in one place against the pipe wall rather than flowing through. That heat is applied to one spot for hours.

• On older PVC it can soften and warp the pipe
• On metal it accelerates corrosion, which creates rough interior surfaces that catch debris faster than before
• On a rubber gasket or a glued joint it degrades the seal
• It does nothing to tree roots, which is what a lot of recurring clogs in this area actually are

The result is a line that drains for a fortnight, then blocks again slightly worse than before, because the surface it is blocking against is now rougher.

The arithmetic of repeat clogs

Say a drain clogs three times a year. Three bottles of cleaner plus an eventual call-out costs more than one proper clearing with a camera inspection, and you have spent nine months living with a slow drain in between.

Clearing a clog is not the same as removing its cause.

A cable punches a hole through the blockage. Water flows again, so the job looks finished. But the grease ring, the scale or the root mass is still there, still narrowing the pipe, still catching the next thing that goes down. That is why a line that is jetted properly stays clear far longer than one that is only cabled.

The expensive version of ignoring it

• A main line that backs up into the house is a category three water loss — that is a restoration job, not a plumbing job
• A clog that turns out to be a collapsed section under a driveway is excavation, and the driveway is part of the bill
• Sewage damage is frequently not covered the way clean-water damage is; check your policy before you need to

What to do instead

1. 1Stop pouring anything caustic down a line that is already fully blocked — it cannot drain, so it just sits there
2. 2Try a plunger and, on a sink, clean the P-trap by hand. That fixes a genuine share of kitchen clogs
3. 3If it clears and comes back within a few months, stop treating the symptom and get the line looked at
4. 4If more than one fixture is affected, it is the main line — call somebody straight away