Water Pressure Problem

Ok here is the deal:

Brick two story semi in Scarborough On.
Buiilt in 1955
House vacant at time of inspection (don’t know how long)
1/2 inch copper water supply line
1/2 inch copper distribution lines
Typical pressure in basement bathroom and laundry area

First floor kitchen pressure/flow was very low
Angle stops appeared to be open all the way.

Second Floor bathroom was the same.

I did recommend further evaluation by a plumber but I have not seen anything like this before.
Any ideas?


Was the pressure actually measured at shut off head in these different areas? Since you didn’t mention actual pressures I will assume not. I will also assume that you turned on some of the faucets and noticed a low “Pressure”. If so, what you are actually seeing is “low volume flow rate”… not “low pressure”. Sounds to me like their is a restriction in the piping and everything beyond that restricted point has a low volume flow rate due to that restriction. When a pipe is restricted the pressure will remain the same at “shut off head” but will drop dramatically when flow is initiated.

oops sorry about the mixup in terms Low volume is what I meant.


I have found in older homes the faucet aerators get clogged or restricted with trash (rust scale) from galvanized pipes and by all appearances has low pressure or flow. I will occasionally removed one, look for debris, tap it out if possible and re-try. It takes only a surprising small amount of grit to stem a faucet flow to a trickle.

First thing I do is unscrew the aerators.

I thought of that as well no change


Douglas, I have this to offer if it helps any;

Some Causes of Low Volume Water Supply

Most low-pressure problems are some times created in the home. The home has adequate water service pressure, but pressure at fixtures drops when another fixture is turned on. This is most commonly encountered when someone flushes a toilet when another person is in the shower. Usually the problem is the water volume is lowered or restricted, reducing the amount of water that comes out of the fixture. Here are some common causes of low water volume. You may have a combination of these problems.

1. Internal plumbing pipes are too small
Water is distributed to your home in a 3/4" or 1" line which can provide a lot of volume and pressure. But, in many homes, internal piping is only 1/2" or less. This reduces the volume of water up to 75%, and can cut the pressure up to 75% as well.

2. Small pipes and a long way to go
In addition to smaller pipes, the problem is worse when water has to go up more floors or travel long distances. This often happens when an additional bathroom and fixtures are added to an older home, but the smaller pipe size is not upgraded. If you’re planning to remodel, be sure to have the water pipe diameter increased to an adequate size.
Long runs of smaller piping reduce the volume of water that can pass through piping, regardless of supply pressure. This is the most common cause of reduced pressure we see in homes in our area.

3. Devices that can affect the volume
Devices such as water softeners, water filters, flow restricting fixtures and decorative faucets can further restrict the volume of water flow in a home.

**4. Piping is getting clogged **
Rust and minerals can build up in older, galvanized plumbing and restrict the flow of water.

5. High on a hill
If your home is at a higher elevation, your water pressure may be below average. If it is below 40 pounds per square inch, a plumber can offer tips for increasing the volume of water to your fixtures.

Talk to a reputable plumber. Usually your plumber can recommend solutions that can enhance your water volume.

Water pressure: the force of water pushing on a unit area, usually measured in pounds per square inch (psi).

Static water pressure: water pressure, measured in psi, at the service line when there isn’t any water running.

Residual water pressure: water pressure at the service line when water is flowing.

Water volume: the amount of water that a pipe can supply. A 1/2" pipe can only deliver a certain amount of water per minute regardless of water pressure.


Low functional flow at the indicated fixtures.

Recommend that the flow and fixtures be evaluated by a Plumber with remedy as necessary.

Could be lots of things.

If it actually has 1/2 inch supply, I would be calling for an upgrade. :shock:

Almost word for word what I told em


Well… homes built in this area after about 1960 or so all have 3/4 supply.

They used 1/2 before that. I always mention the 1/2 inch supply and advise that 3/4 is the current standard.

Still see galvanized and even some lead in the older parts of the city. Always suggest that stuff be upgraded.


Yeah could be foreign material clogged in the line assuming the kitchen risers and bathroom risers are lined up vertically.

All this pressure vs. volume flow rate talk has reminded me of a situation I had back in the 80"s. This was pre-HI for me as I owned a hardware store in the boonies of northern NH. I designed a water system for a customer and sold the product to him. His own plumber did the install. It involved an open well with pump and x-trol tank at the well, approx.1200 feet of 2inch black plastic water pipe to the house, and another x-trol tank there at the house.
The system was installed using 2-600 foot rolls of 2" pipe buried 6 feet deep while the house was being built and all seemed well until the family moved in. The owner started complaining that the water pressure fluctuated wildly and at times they could get very little water. At other times all was well.
I spent a half day testing the pumping end and the recieving ends of the system… all was well! However, I did note that the when the house used water the house tank lost pressure rapidly and the pump end of the system could not make it up fast enough. Something was wrong with the 1200 feet of pipe. I surmised that a rock had been laid on the pipe while backfilling and had crimped the pipe. I had seen it many times before on smaller systems. But where? Would we have to dig up the entire pipe to find it. And, who would pay for all the digging and replacement of the pipe.
There was alot of arguing, blaming, and finger pointing over the next couple of weeks, including towards the manufacturer of the pipe. It was settled that it would be dug up and whoever was responsible for the fault, including the manufacturer, would pay. And, all of us would pay if no fault was found at all.
The morning of the “big dig” I awoke about 4:00 am and kept thinking "what could it be if not a rock crimping the pipe. I arrived on site at 6:30 am and by the time the two backhoes arrived I had an idea. I asked one backhoe driver to start in the middle of the pipe and dig up the only connection in the entire 1200 feet. It took about 1/2 hour and up came the center pipe connection. Except, what should have been a 2 inch coupling(double clamped on both sides) was a gomme of reducing couplings and about three feet of 3/8 inch soft copper tubing. The plumbers crew had come up three feet short (on a friday afternoon) and instead of taking the time to get the right fittings and pipe, they had used whatever they could find on the truck. Starting in the middle had saved alot of money that day. And once the plumber saw the jury-rig he wrote a check on the spot and took care to repair the piping himself (mud and all).
The day ended on a very happy note with plenty of beer to go around(purchased by the plumber, of course) and not a lawyer in sight. Today, in Metro Nashville, I long for those days, out in the country of Northern New Hampshire, where Men might argue, even piss and moan at each other, but all the while knowing that, in the end, if the problem was to be solved, everyone involved had to come together to solve it. The only ones that didn’t make out so well, were the guys on the crew that had come up with that friday afternoon jury-rig in the first place!

A very interesting story Larry, I had similar experiences in the past.
Work together as a team. Finger pointing solves nothing.:slight_smile:

Thanks Marcel. My family comes from the Bangor, Ellsworth area, although I have not been there in years. My undergraduate degree is from UM Orono. I must admit though, my favorite area of Maine is the Belfast to Penobscot Bay area. I spent years sailing Pen Bay. I would be willing to bet that alot has changed in the past 20 years though.

Glad to here that Larry, and don’t worry, not much changes up here in twenty years.:slight_smile:

I must have missed something??

You long for the days where A Holes install half assed crap??

Or you long for the days where the guys that installed the crap won’t come forward and tell someone what they did and save everyone the time and aggravation to correct it?

Ahhh the good old days.:roll:

Check the shut off valves also if they are older ones they can be installed backwards , Look for a arrow

You missed the point my good man. If you had ever had employees you would know that the situation you took as the point above will exist until the end of time. The by gone days that “are missed” by me are those days when in the end we stopped caring who was right and who was wrong and came together to solve the problem. Today we have “progressed” to a point where it is more important than anything else to be “right”. Bring on the lawyers boys… we will prove ourselves correct or take everyone around us down too… screw the problem!

Or maybe, you didn’t miss the point and just enjoy seeing the negative side. Who knows? Each to his own…!
“Not everyone follows the same path”

I understood the part about laywers. So?? I thougt it was you who was making excuses for lazy workers. (my point):wink:

“Ah the good old days where a couple of lazy bastards could screw up a job and cause umpteem workers a days work to correct a minor problem.”:frowning:

“And not to worry, we won’t hold those responsible for their misdeeds, so more than likely they will continue with their lazy ways.”:frowning:

But then again maybe you were on T&M and were jsut there getting a paycheck at the Clients expense??

I recall those days too, they sucked, and guys that had work ethics like that also sucked. Yep worked on many a job like that, even fired some of those guys. Why, because I have sorta a “Root Cause” perspective.:smiley:

But then again as you “Know Me” so well, WTF do I know???:twisted: