If a drain clogs again weeks after it was cleaned, the cleaning did not remove the cause. Snaking punches a hole through a blockage; it does not always remove what is blocking the pipe. The cause is usually one of four things, and a camera inspection is how you tell them apart.
Roots in a clay lateral
Why snaking alone does not last
The most common cause in Denver's older neighbourhoods. Clay sewer laterals are jointed, and tree roots enter at every joint. A snake cuts the roots inside the pipe, but they grow back through the same joints. Capitol Hill, Park Hill, Baker, Congress Park and Washington Park all have mature trees over century-old clay laterals. The lasting answers are root cutting with hydro jetting, a spot repair, or a replacement, decided by what the camera shows.
Scale in cast iron
Cast-iron drains corrode and scale from the inside, narrowing the bore until the pipe clogs on normal use. Snaking clears the immediate blockage but leaves the scale. Hydro jetting at 3,000-4,000 PSI scours the pipe wall and restores the bore, but only after a camera check confirms the pipe can take it. See hydro jetting.
A belly in the line
A belly is a sagging section of pipe where water and solids collect. It is common where expansive bentonite clay has moved under the line. No amount of cleaning fixes a belly: the pipe holds water after every flush. The fix is a spot repair or a replacement of the bellied section. See sewer line repair.
A collapsed or broken section
A collapsed or badly offset section will clog again no matter how it is cleaned, and jetting a collapsed pipe makes it worse. This is the case a camera inspection is for: it shows the break, its position and its length, and it decides whether the answer is a spot repair, a trenchless lining, or a full sewer line replacement.
What a camera inspection shows
Footage marks and a locate
A recorded camera scope with footage marks and a locate shows the material, the damage and the position. It is the difference between clearing the same drain every few months and fixing the cause once. It is also standard practice before buying a Denver home, because clay laterals are a hidden liability. See sewer camera inspection and drain cleaning. Call (720) 599-7253 if your drain has clogged twice in a year.