low water pressure - Posted by Andrew

Posted by Vic on June 27, 2005 at 02:15:41:

Wish I could help you on this more Andrew.

I think what I would do, if you haven’t already, is pay for a good plumber to come take a look at what you have going on there.

I know that if you have to replace all or even part of the water lines, that it can get quite expensive, especially on a 8 unit.

I’m in process of replacing just the hot water lines on 3 br/2 ba single house, due to rust & it’s running me $2800, just for the hot water lines. That’s only going from water heater to various faucets too.

So, before I bought that I would definitely want to find out what I was getting into with that plumbing. Since it’s an old place, you might want to check the drain lines too to make sure it can accomodate washing machines (if there are any) & that you don’t have any cracks.

Major plumbing problems is the last thing you need on an 8-plex.

Good Luck & keep us posted.


low water pressure - Posted by Andrew

Posted by Andrew on June 20, 2005 at 14:57:14:

I look after an 8 plex in Toronto. The water output from the taps in the building is very low. I am presently determining if this is pressure or flow problem. This low water output has been a problem for many many years according to the superintendant. the building was built in 1960.

I am trying to determine whether to install a pressure pump with a 120 gallon prsssure tank (at a cost of about $1000), or upgrade the 5/8ths inch copper water supply line to the building (this will cost over $10,000). The city tells me that since this is a commercial (multi residetial property I am responsible for replacing the city owned line from the city water main to my property line.

Any suggestions or experiences would be very much appreciated.


Re: low water pressure - Posted by Vic

Posted by Vic on June 25, 2005 at 22:46:33:

Are the pipes galvanized? If so, you could have rust in the lines preventing the water from flowing. My last 3 rehabs had this problem. Not a cheap one to fix though - especially in an 8-plex.


Re: low water pressure - Posted by Don Dion

Posted by Don Dion on June 20, 2005 at 18:39:24:

Are you sure about your sizes for the water supply line from the street? I have done projects in IL and MI and the supply line from the street is 1 1/2" and is knocked down to 3/4" for the long runs in the house and showers then 1/2" to service lines.
A 5/8" line for a multi unit is severly undersized. Watch out for the pump idea you might want to check with a plumber or public works before you try that one. The worry there is when you pump water out of a system you generate a whorlpool effect on the city main and it tends to release potential bacteria to the pumped site. This is not a problem with free flowing water at the city normal presure it only becomes a problem when you pump from a presure source. Shure would be bad news to save a few bucks then have your tenants get sick.

Re: low water pressure - Posted by Andrew

Posted by Andrew on June 26, 2005 at 06:32:18:

Good Point Vic.

I checked the building before I took it over for galvanized pipes. I can find no evidence at all of galvanized piping. Everything that I have seen is copper. I have opened walls during repairing the apartments and have never seen galvanized, except for the radiator heating pipes (I am told they are actually “black pipe”).

However a plumber that works in the area and has experience with buildings like mine says the risers are probably galvanized. I do not know wherre my risers are (I may not even have true risers because it is a small building). City hall has not provided me with drawings of the building which would allow me to locate the risers and inspect them. From all my research of the building, I dont think I have any galvanized piping.

Another reason I dont think my risers are blocked is because, the farthest faucet on the top floor (3 stories) from the water supply line in to the building will give me good flow when I open it, if other faucets in the building are not opened. Does that make sense, or am I missing something.

Yesterday I put a water gauge on the laundry taps and turned on the washing machine. The pressure dropped from 70lbs to 40lbs and stayed there until the wsher stopped filling. Neither of the water lines that supply the laundry area run thru risers. Yet I am still getting a dramatic drop in pressure even on the lower level of the building.

I am thinking that my supply line is partially blocked and also too small for the buildings needs. I have done some reseach and am leaning towards a large pressure tank and pressure booster pump.

Any ideas would be very much appreciated.


Re: low water pressure - Posted by Andrew

Posted by Andrew on June 21, 2005 at 06:17:23:

I am not sure if the supply line is 5/8ths all the way to the city main. Hopefully the city can give me this info, so far they dont know. I agree 5/8ths is ridiculous for an 8plex, I would think there would have been a water supply problem from day (45 years ago).

Your point about the bacteria is a good one,I will have to investigate it further. Large apartment buildings do use a pressure pump on the city supply line to supply water to the upper floors in our area. I am awaiting the city estimate of how much they will charge me to replace their supply line.


It may be caused by debris such as dirt, sand, solidified oil and grease, food particles, or foreign objects. Pollutants can block pipes if they back up due to fractures in the water main. Mineral buildup clogs pipes over time and causes the Water Supply pressure to go down, as there’s less space for water to travel through.