Before the First Storm: Four Plumbing Checks to Make While the Ground Is Still Dry

The first real rain in this area usually lands somewhere between the middle of October and the middle of November. After that the ground stays wet until spring, and December and January alone bring close to half the year’s total rainfall.

That gap, the few weeks before the first storm, is the cheapest time of year to deal with a plumbing problem. Everything below is easier in dry weather, and most of it you can check yourself in an afternoon.

What rain actually does to a sewer line

A sewer lateral is the pipe that carries waste from your house to the city main under the street. In dry weather it handles what your household sends down it and nothing else.

Rain changes that. Saturated soil pushes groundwater up against the pipe, and any crack, offset joint or loose fitting lets that water in. Plumbers call it infiltration. A line that ran fine all summer is suddenly running near capacity before anyone in the house has turned on a faucet.

Add a partial blockage to a line that is already full, and you get a backup. This is why so many sewer calls come in the week after the first storm rather than during the dry months, and why a drain that has been a little slow since August is worth taking seriously this fall.

Soil movement plays a part too. Ground that dries and shrinks over the summer swells again when it gets wet, and old clay or cast iron joints shift with it.

Check one: find your cleanout, or find out you do not have one

A cleanout is a capped pipe sticking up at ground level, usually near the foundation or out by the property line. It gives a plumber, or the city, direct access to the lateral without going through a toilet.

Here is why it matters more than most homeowners realize. In Sunnyvale the lateral is the property owner’s responsibility, and the city will help locate a blockage and may clear the lower portion of the lateral only when a cleanout at the property line exists. Santa Clara works the same way. The city crew checks the main in the street, then checks the lower lateral from the property line to the main if there is an accessible cleanout, and tells you if the problem is on your side.

Without a cleanout, none of that happens. The city cannot assess the lower lateral, so you end up paying to diagnose a blockage that might not even be on your property.

What to do this month:

• Walk the perimeter of the house and look for a capped pipe, usually three or four inches across, in the ground or just above it.
• Clear the soil, bark and plants that have grown over it since spring. A cleanout nobody can find is the same as no cleanout.
• Mark it with something you will still see in the dark and the rain.
• If you cannot find one, this is the month to have a cleanout installed at the property line, while the ground is still dry enough to dig.

Check two: look under the house before the ground gets soft

Plenty of homes here sit over a crawl space rather than a slab. Once the soil under the house saturates, it stays damp for months, and a slow drip that would have evaporated in July turns into standing water that nobody sees until it smells.

Take a flashlight and look for four things.

• Damp or dark soil directly under a supply line, especially where copper meets an older fitting.
• Green or white crust on copper pipe. That is corrosion, and it means water has been sitting there.
• A musty smell, which usually arrives before any visible water does.
• A vapor barrier that has slipped or torn, leaving bare ground exposed.

There is also a check that takes thirty seconds and requires no crawling. Turn off every fixture and appliance in the house, then look at the water meter. If the dial is still creeping, water is going somewhere. Under a crawl space home, that somewhere is often underneath you.

Finding a leaking section of pipe in October means working in a dry crawl space. Finding it in January means working in mud, and by then it has been feeding the soil under your foundation for two months.

Check three: the condensate drain, before the heating season starts

Condensate is the water that drips off cold equipment. An air conditioner produces it all summer. So does a heat pump water heater, and so does high-efficiency heating equipment once the weather turns.

All of that water leaves through a narrow drain line, and over a summer of running, that line collects a slimy buildup that narrows it further. Fall is when it gives out, because the equipment switches over and the line gets asked to move water again after sitting idle.

The result is usually water on a garage floor, a brown stain spreading on a ceiling below an attic unit, or equipment that shuts itself off because the pan sensor tripped.

The check is simple. Find the drain pan under the unit, pour a cup of water into it, and watch whether it drains away or sits there. Look at the floor and the ceiling nearby for old staining, which tells you it has overflowed before.

If the line is blocked, we clear the drain line itself and re-secure it where it has come loose. The equipment it serves belongs to your heating and cooling contractor, but the drain it empties into is plumbing.

Check four: deal with any drain that has been slow since summer

A drain that is merely slow in dry weather is a drain that backs up in a storm. That is the whole point of doing this before the rain starts.

Snaking and jetting are not the same tool. A cable punches a hole through the middle of a blockage, which restores flow and leaves the buildup on the pipe wall. Jetting sends water through a nozzle at high pressure and scours the pipe wall back to its original diameter. The hole a cable makes closes again. The wall a jetter cleans stays clean much longer.

Jetting earns its place in a few specific situations: a kitchen line coated in years of grease, a long lateral run where a cable loses its reach, and any line that has clogged twice in the same spot.

Before either one, it is worth putting a camera down the line to see what you are dealing with. There is a real difference between a pipe full of buildup, which cleaning solves, and a pipe with a crack, an offset joint or roots that have found their way in, which cleaning only buys time on. Knowing which one you have changes what you should spend money on.

If the first storm gets here before you do

Order matters when a backup starts, and most people get it backwards.

If more than one fixture is affected, a toilet and a shower at the same time, the problem is in the lateral rather than in that one fixture. Stop running water immediately. Every gallon that goes down a drain in the house has to come back up somewhere.

Then call the city before you call anyone else. Sunnyvale runs a sewer response line and sends someone out to find where the problem starts. Santa Clara does the same through its Water and Sewer Utilities department. If the trouble is in the main or in the lower lateral, that is the city’s work and not yours. If it is on your side of the property line, you now know that for certain, and a plumber can go straight to the repair instead of spending the first hour figuring out whose pipe it is.

That call costs you nothing and can save you an entire service visit.

Questions we get every fall

How do I know whether I have a cleanout at all?

Look for a capped pipe at ground level, most often within a few feet of the foundation on the side of the house where the bathrooms are, or near the front property line. If a previous owner landscaped over it, a camera inspection will locate it. Older homes here frequently have none.

My drains are all running fine. Is there anything to do?

Find the cleanout, clear it off, and check the crawl space. That is it. A house with no symptoms does not need its lines cleaned on a schedule.

Is snaking ever enough?

Often, yes. A single toilet or sink that clogged once and cleared easily does not need anything more. Jetting is for lines that keep failing in the same place or that carry years of grease.

Who pays if the blockage turns out to be in the street?

The city maintains the main. Confirming that is exactly what the city visit is for, which is the reason to make that call first.