A slow shower is almost always hair. It collects on the strainer crossbars, winds into a rope in the trap and catches soap scum until the water backs up around your feet. That problem is fixed with a hook, a plastic strip or a small hand snake in ten minutes, and no camera is needed. The cases that need a camera are the ones that come back after the hair is gone: a shower that drains slowly with a clean trap, a shower that smells, a shower whose floor is soft or whose ceiling below is stained, or a shower in a slab house where the drain seems to be backing up from below rather than clogging from above.
Quick answer: clear the hair first and check the trap. If the shower still drains slowly, gurgles, smells, or shows water damage below, a 17 or 18 mm camera on a thin rod through the drain inspects the trap arm and the branch line for a crushed or separated section, a belly, a scale lip in galvanized pipe, or a connection problem at the main. A shower pan leak is not a drain problem and the camera will not find it; a water test of the pan will. In a slab house, a shower that backs up is often the first sign of a building drain problem that affects every fixture.
The hair stage
Remove the strainer. Pull what is visible. Use a plastic barbed strip or a small hand snake through the drain into the trap. Flush with hot water. If the shower drains freely afterward, that was the problem, and a strainer that catches hair before it enters the trap is the prevention. If it does not, or if it is slow again within days, something else is going on. Tools for small branch lines covers the hand tools.
When the camera is worth it
A clean trap and a slow drain. Gurgling at the shower when the toilet flushes. A persistent smell from the drain with the trap full. A soft spot in the floor around the shower, a stain on the ceiling below, or dampness in the crawlspace under it. A shower in a slab house that backs up with grey water that is not its own. Any of these means the problem is downstream of the trap, in the trap arm, the branch or the building drain, and a camera is the way to see it. Inspecting a bathroom group drain covers the branch.
What the camera finds
A trap arm or branch in galvanized steel narrowed by rust, with a scale lip at every fitting; common in pre-1960 houses and a replacement finding. A belly in the branch holding water and soap scum. A crushed or deflected section where the pipe passes under a joist or a footing. A separated joint with soil or insulation visible, which is the cause of the damp below. A branch tap into the main that is protruding or broken. A vent connection that is blocked, which explains the gurgle. And in a slab house, a building drain beyond the branch that is scaled, channeled or blocked, which explains why the shower is the fixture that backs up: it is the lowest. The galvanized guide covers the first case.
What the camera will not find
A leaking shower pan. The pan is outside the drain, between the tile and the subfloor, and a failed pan leaks when the shower is used regardless of the drain’s condition. The test is to plug the drain, fill the pan with water to the curb, and watch for leakage below over an hour. A failed drain flange seal, where the pan connects to the drain body, is similar. Both are tile and waterproofing work, not drain work, and a camera inspection that finds a sound drain in a shower with a stained ceiling below has pointed at the pan by elimination.
The equipment
A shower drain is 2 in with a trap directly below it, and the camera has to be a 17 or 18 mm head on a 5 mm rod to make the trap. A 23 mm full reel will not enter it. A detachable or well-placed screen helps, because the work is done kneeling in the shower. The P-trap camera guide and the small-line camera guide cover the options. For the building drain beyond the branch in a slab house, a full reel from a cleanout or a pulled toilet is the tool.
What to record
What was removed from the trap, how the drain behaved afterward, and, if the camera went in, the material of the trap arm and branch, any lip, belly or crushed section with its distance from the drain, and the condition of the connection at the stack. If the pan test was done, its result. A shower that has been through all of that has either a found defect or a confirmed pan leak, and either is something a contractor can quote.
Common questions
Why is my shower slow when the trap is clean?
The problem is further along: a belly, a rust lip, a crushed section or a blocked vent. A small camera through the drain finds it.
Can a camera find a shower pan leak?
No. The pan is outside the pipe. A water test of the pan finds it.
Why does the shower back up when the toilet flushes?
Because the shower is the lowest open drain and the branch or building drain they share is partly blocked. That is a main line inspection.
Related guides
See camera inspection of a basement floor drain, the best sewer cameras for basement drains, and whole-house slow drains.