The three things that cause them
Worth separating, because prevention differs completely between them.
Accumulation from the house. Grease that solidifies once it cools, wipes that never break down, and the general narrowing of a line that gets no maintenance. This is entirely within your control.
Roots. They do not break sound pipe — they find an existing crack or separated joint where moisture escapes, then expand. So a root problem is really a joint problem that roots have located. Cutting them treats this season only.
Ground movement. Our expansive clay swells wet and shrinks dry, and buried pipe absorbs that. Over years it pulls joints apart and drops sags into runs that were laid to fall correctly. A sag holds standing water and catches solids, which produces repeat blockages in pipe that is otherwise intact.
The first is habits. The second and third are found by camera and fixed by repair — no amount of care prevents them.
The habits that genuinely matter
Short list, and the first two account for most of it.
- No grease down the sink, ever. It goes down liquid and is solid twenty feet along. Hot water and detergent relocate the problem rather than solving it. Cool it, set it, bin it.
- Nothing down the toilet but waste and toilet paper. Wipes, including “flushable” ones, cotton buds, floss, sanitary products, cat litter and paper towel all survive the trip and catch on the first imperfection they meet.
- Hair catchers on showers and basins. Cheap, and they prevent more call-outs than anything else on this list.
- Run cold water with a disposal, and let it run 15-20 seconds after the grinding stops so the waste actually clears the trap.
- No coffee grounds or eggshells. They settle and pack rather than flowing.
Worth knowing
If a house has had one backup, the habits alone will not prevent the next one. Something caused the first — and if it was roots or a sag, it is still there. That is the point at which an inspection is worth more than any amount of care.
Trees, and the honest trade-off
Roots follow moisture, and a sewer line is a reliable source of it in a dry Hill Country summer. Species with aggressive root systems planted over or near a line will find it.
The realistic advice is not to remove mature trees — that is rarely proportionate, and the trees are usually why people wanted the property.
What is proportionate: know where your line runs, avoid planting anything new over it, and if you have large trees near the route, treat a camera inspection as periodic maintenance rather than an emergency response.
Where roots are already entering, cutting them is a holding action. Lining the pipe seals the joints they come in through, which is what actually ends it — covered in repair versus replacement.
The backwater valve
This is the one device worth knowing about, because it addresses a backup you cannot prevent by any other means.
If the municipal main surcharges — during heavy rain, or a blockage downstream — sewage can flow backwards into the lowest fixtures in the lowest house on the run. Nothing you do inside your home affects that. It is not your line failing.
A backwater valve is a one-way flap fitted into the lateral. Normal flow passes; reverse flow closes it. Fitted correctly, it is the difference between a difficult evening and a contaminated ground floor.
It is worth considering if your house sits low relative to the street, if you have had a backup that coincided with heavy rain, or if you have finished space at the lowest level.
One caveat: it needs to be accessible and inspected periodically. A valve that has silted up or jammed open provides nothing, and one jammed shut causes its own problem.
Catching it early
Backups give warning. The signs are gurgling when another fixture drains, more than one drain slowing at once, and water rising in a shower when the washing machine discharges.
That last one is the clearest test in the house, and it costs nothing. If the main cannot take the washing machine's discharge, it will not take much else either.
Acting on those is the difference between a scheduled visit and a cleanup. The symptoms and what each means are in what each sewer sign tells you.
One more thing worth doing: find your sewer cleanout and make sure it is accessible. It is usually a capped pipe near the house or at the property line. Clearing a line without one costs more and takes longer, and hunting for it under a shrub while sewage backs up is nobody's best moment.