I'm not a plumber, but I have done my share of copper runs and I've never seen 1/4" used for anything but an icemaker supply. You've got it pretty well figured out. The 1/4" is really restricting flow. You need to replace all of it with at least 1/2" copper. Also, depending on how old your house is, the steel pipe might be suffering from hardening of the arteries and also be causing low flow. Galvanized steel pipe generally is pretty well shot after 40 years, so you may have some major re-plumbing to do.

One thing you could do yourself is assess is flow rates. First, see how much water you get out of any spigot closest to the incoming supply (like one of your outside hose bibbs nearest the meter). I believe a typical flow rate for the average house should be about 5-10 gallons per minute (gpm). You can determine yours by taking a gallon milk jug and timing how long it takes to fill when the spigot is wide open. Divide 60 seconds by the number of seconds to fill the gallon jug and you'll have your gpm rate. For example, if it takes 12 seconds to fill the jug, your flow rate is 5 gpm (60/12). You could also do this experiment elsewhere in the house and see what the fall-off in rate is in other locations.

Hopefully you have a digital camera so I might convince you to take lots of photo's and email them to me to be added to my library of things that should never be done...LOL.

Having said that, I would also like to point out that the cold water supply is sized correctly until it gets to the 1/4" feeding the water heater , which is totally incorrect.

From your description I gather that your house is one story on slab with a crawl space and you have 2 full baths,(standard bath group-tub/shower, lavatory & water closet) kitchen, laundry and a minimum of one outside hose bibb. It also appears that the water heater is mounted on the opposite end of the house from where the water main enters the structure.

Per table T-2903.6 in the International Residential Code your demand is 5.9 Fixture Units of Hot Water and 11.9 Fixture Units of Cold Water for a total combined load of 17.8 Fixture Units on the structure.

Even at the minimum of 40psi static head pressure your 1" supply and 3/4" main distribution line is adequate if the length of run from the municipal main or well pump to the furthest fixture does not exceed 200'.

Having said that, we must also take into consideration that those figures are for pipe which remains at full bore however you have galvanized iron pipe and if that pipe is 40 or more years old there is a strong likelyhood that internal mineral scaling has by now reduced the effective diameter of the pipe to 1/2 its rated volume or less.

Based upon the load calculation tables you should have a 1" supply from the municipal main or well pump to the structure and you should have a 1" full bore shutoff valve. (Gate valve or ball valve-no globe valves).

The main cold water line should then be a 3/4" line with 1/2" branches to each bathroom, kitchen and laundry. At the point where the last 1/2" branch Tee's off the cold water line would then be reduced to 1/2" to the water heater and all hot water lines would be 1/2".

Although that would be minimum I would personally prefer a slight variation.

From the 1" shutoff I would continue the 1" cold water line with a 1/2" branch tee'd off to each bathroom, kitchen and laundry. At the point where the last branch line tee's off I would reduce the line to 3/4" from that point to the water heater then make all hot water lines from the water heater 1/2".

Increasing to 3/4" on the downstream side of the water heater would not increase either volume or pressure but it would dramtically reduce the velocity of flow. This would cause excessive delay to get hot water to the fixtures as well as significantly increase the amount of thermal energy lost to radiation from the pipes.

Thanks both of you for responding. I'll do a flow rate test as suggested on the cold water side and maybe do a psi check also. Without even doing a test, I'm sure there are no flow rate issues on the cold water side. I can fill a 55 gal barrel pretty quick from the hose bib.

Lazyboy, you got the house nailed pretty good except most of the house is on a perimeter foundation. just a family room and the laundry are on slab. Yes the laundry is on other side of house from water supply.

I think all the iron pipes under the crawl space are not the original judging by their outside looks and inside of a few I've had apart for this or that. They look pretty good inside so I think the house was re-piped at one time.
When I take shower heads of and faucet aireators, I always have grit and sand it them. Btw, I'm on city water so I can't really understand all the grit.

So, could I get by with this scenario?

1. Cold water side. Reduce from 3/4" iron to 1/2" copper into the water heater.
2. Hot water side. Out from w/h with 1/2" copper back to main 3/4" iron wich is teed up to shower/laundry/sinks etc with 1/2".
   In other words, just replace all the 1/4" copper with 1/2".

Your suggestion at the bottom of your post does sound like the way to go but at the moment I've got to many other projects cooking I have to finish.

Thanks

Al

You cannot do a flow rate test in the manner described above because the fixtures all are designed for different flow rates. An outside hose bibb is designed for 5gpm while a tub mixer is rated at 4gpm and a lavatory faucett is 2gpm. In order to get an accurate comparison you must measure both the hot & cold individually at the same faucett.

Performing pressure tests throughout the system would yield no truely useful information. When all faucetts in the system are closed the pressure at all points in the system will be at equilibrium with the supply pressure (Static Head Pressure) regardless of what size the piping may be. The only notable variable here would be slight changes of "Vertical Static Head" which result from differences in elevation between the points under observation.

Whenever any faucett is opened and flow begins the pressure throughout the system instantly drops from "Static Head Pressure" to "Dynaic Head" (working pressure) which will vary greatly by the number of faucetts opened and the volume of flow. The difference between Static Head Pressure and Dynamic Head Pressure can be very significant, by example, the International Residential Code minimum permissable Static Head Pressure is 40psi while the minimum permissible Dynamic Head Pressure at a shower mixer is only 8psi.

I would expect that you are correct, if you were to change out the 1/4" copper for 1/2" you should be able to restore the volume and pressure at least to the best available depending upon the overall condition of the remaining galvanized iron piping throughout the system.

I suspect that the 1/4" copper was installed as a DIY project and you have very limited access under the slab which accounts for why they fished the 1/4" through. You can follw there lead and fish 1/2" roll copper pipe through in the same manner and remain fully code compliant.

Here are a couple tips that may help you.

Begin by cutting the 1/4" tubing loose at both ends but do not pull it out. Instead, insert one end of the 1/4" inside the end of your 1/2" roll copper pipe, crimp the 1/2" down against the 1/4" and solder the two together. You can then use the 1/4" to pull the 1/2" through but be very careful and have an assistant feeding the 1/2" as you pull to insure you do not kink it anywhere.

There is an alternative that you may prefer to try. Instead of running roll copper you may want to replace that section with PEX. You could begin by cutting the 1/4" tubing on both ends, then on one end take a 8 or 10" piece of AWG 12 bare copper electrical wire and fold it in half then insert the ends into the 1/4" copper and solder it in, forming a wire loop on the end of the 1/4" tubing. Attach a 1/4" diameter rope to the loop so as you pull the copper out it will pull the rope through. Once you have the copper out you can get an exact measurement and you could have a plumber preassemble a pair of PEX lines with the appropriate fittings on the ends. In this manner you will not need to worry about where to get the PEX tools. You then attach the PEX to the rope and use the rope to pull the PEX back through.

one word of caution. Code prohibits directly connecting copper to iron pipe or vessels. You will need a Dielectric Nipple, Dielectric Union or a 6" hardened bronze nipple at each point of transition from Copper to the Galvanized Iron Pipe or to connect the PEX connectors to the Iron Pipe or water heater vessel.

In regards to your question about sand in the pipes. As galvanized iron pipe ages it forms mineral scale on the inner walls of the pipe which normally forms in crystals that appear like white, light browu or sometimes a translucent honey collored particle that looks like grains of sand. We often find GIP that is so full of the scale the the entire inside of the pipe appears like its full of wet sand.

Lazypup (got the name right this time), Thanks for taking the time for all that info. I'm going to do like you said in your first post in that I'm going to continue the 3/4" cold supply into the water heater and then come out with the half inch and step it back up to the 3/4 main hot line. I'll do all that with the GID as I don't see any benefit to sticking copper in there if the rest of the pipes are not copper also.

Your suggestions for getting the half inch copper back up through the slab are very helpful but I think I'm going to have to find another way to route the pipes to the water heater. Those 1/4" pipes go through the slab and then come up through the wall and out to the w/h at about six feet up the wall. That wall sits on a perimiter foundation with the slab floor in between the foudation. This being out in the laundry room. The route those pipes take must be through the slab, then a 90 into the foundation then another 90 up through the foundation and the sill plate then six feet up the wall and another 90 out of the wall. There can't be any way I could fish pipe through all those 90's

What I really need to do is get the sheetrock off the wall by the water heater and find out just what the deal is.

I have an idea to get the pipes in and out to the w/h but it would involve a horizontall run through a load bearing wall. I have no idea if that's to code or allowed.

Should I just call a plumber? Will I be able to find one that will crawl 50-60 feet through a 2.5' crawl space. I know the cable guy refused to do it for any price ha ha.

Thanks

Al