This Old San Carlos House, Part IV: Plumbing.

August 2, 2011


Water In, Water Out.

One of the most essential functions in a house, albeit one of the most unspectacular, is the method of getting water into and out of the structure … aka plumbing.  And while we tend to associate plumbing with the aspects that are visible, such as our fancy faucets and expensive fixtures, most of the important stuff that pertains to plumbing happens out of sight, either behind the walls or under the earth.

The basics of plumbing haven't evolved a whole bunch since homes were built in San Carlos in the 1940's and 50's;  water goes in, and something in a liquid form comes back out.  But the materials that are used have indeed changed, and it's important to understand what your dealing with in your Old San Carlos House, because plumbing repairs can range from the hundreds of dollars to the thousands, depending on what you're dealing with.

Supply and Distribution.

Back when most San Carlos homes were built, plumbers used galvanized steel piping to supply and distribute water throughout the house.   Galvanized steel pipe was inexpensive, readily available (except for in WWII), and easy to work with.

Galvanized Steel Pipe

Joints and couplings were made by threading the pipe and connecting elbows or other sections of pipe.  Galvanized steel served its duty well for many years, but this material does have a couple of shortcomings.  First, it will erode over time — especially after prolonged exposure to water.  This can leave weak or leaky pipes in the worst case scenario.   But the more noticeable shortcoming with steel piping is that it's prone to occlusion — the build-up of mineral deposits and sediment on the inner wall of the pipes.  This is similar to what happens to your arteries when after you eat a double-double with animal fries at In-N-Out Burger.

Over time, these deposits build up in the pipes and restrict water flow to the faucets.   Most often, the symptoms are mistakenly diagnosed as low water pressure, when in reality it's low water volume.    Today, plumbers use copper piping for supply and distribution lines almost exclusively.

Copper Water Pipes

Copper resists occlusion and doesn't rust or degrade after exposure to water, but working with the material takes a bit more skill since plumbers now have to weld the joints and couplings instead of threading them.

If you want copper piping in your home but don't want to wait until you do a full remodel, there are companies that specialize in re-piping your existing plumbing in copper.  It usually runs several thousand dollars, but it's an easy investment to recoup when you go to sell the home later.

Taking it to the Streets.

If you think plumbing is an unsexy aspect of the house, wait until you have to deal with the waste lines.   All of the drains that are in the house — whether it's from the sink, shower, bathtub, dishwasher, and yes, the toilets — all connect by a series of waste lines into a single exit pipe, known as a sewer lateral, that carries everything directly to the main city sewer connection.  Back when these homes were first built, cast-iron was the material of choice for waste lines inside the house, but that has since changed to ABS plastic piping.   It's lighter and easier to work with than cast iron.

Plastic Waste Lines

Because homes of the advancing age of many of the homes in San Carlos, problems with the sewer lateral are rapidly becoming the most troublesome and expensive plumbing problems to fix.  Since the lateral is underground and out of sight, unsuspecting homeowners (or new buyers) usually don't know they have a problem with their lateral until it actually fails — either resulting in a backup of the entire waste system, or a leakage of raw sewage.  Neither are good.

Repairing underground waste lines is very labor intensive, and consequently expensive.   Since the entire pipe has to be exposed, it means trenching through whatever is above it — landscaping, fences, and yes…even the driveway.    Consequently, it's VERY important that you ensure the waste system in your Old San Carlos Home is functioning properly.  More on that below.

In Hot Water.

Getting hot water through the house for showers and other miscellaneous cleaning functions has only started to change in the past 10 years or so.  The old workhorse hot water heater is still used in the vast majority of houses.   Your happiness with this kind of heater is usually dependent on how new it is, and how much water it holds.  Newer hot water heaters are more energy efficient, so they're less money to operate.  And larger hot water heaters are vital for larger families, specially those with TEENAGERS.

A growing fad in home-building is to use “tank-less” hot water heaters.  This method heats the water as it enters the house, thus providing (in theory) an endless supply of hot water.

Diagram of a Tank-less Hot Water Heater

Look Before You Buy.

If you're thinking about buying an Old San Carlos House, how do you ensure that the plumbing is up to snuff, and not a perpetual drain on your finances?    Get it inspected.    A competent general home inspection will identify whether you have copper or galvanized piping, and the general condition of those pipes.  The inspector can also render a judgement on the condition of any visible waste lines.    But knowing that the biggest and baddest problems happen out of sight, how can you be sure of the rest of the system?

More plumbers are now offering specialized plumbing inspections, which delve into details beyond the standard property inspection.  For example,  to overcome the invisibility of the sewer lateral, they can now thread a video camera down the sewer line to assess the condition of the lateral all the way up to the connection to the city system.   This inspection alone is worth the price many times over if you can identify a costly fault in the system.  Plumbers can also tell whether the original plumbing installation was done per the building code by a licensed plumber, or whether it was a “weekend warrior” job.

The Bottom Line.

If you're looking at Old San Carlos Homes, it's likely that they have old San Carlos plumbing.   But it shouldn't be a reason not to by the house.  A thorough inspection of the plumbing system will tell you whether you have a workable system, or whether you're just buying somebody else's problem.


This Old San Carlos House” is an occasional series on the White Oaks Blog.

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  1. In & Out Plumbing on August 12, 2011 at 10:49 am

    Nicely explained. Truly impressive and nice information. Thanks for sharing.

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