Why does a retired computer scientist know more about plumbing than the professionals?

[tvrgeek]

Hey, I am reasonably smart, but no genius by any means. When I don't understand something, I do a little research. ( so a lot of time researching) Doing some minor work on my home, built in '92, I find electrical, framing, HVAC, and plumbing code errors as well as just plain bad practice. Why is it that "professionals" can't do it correctly?

A good example of bad, ignorant, or don't care is I just paid a bunch of money to a major plumbing company to re-plumb my house eliminating the old PB tubing in favor of PEX. At the same time, I put in all new Delta fixtures. I would up with only 1.8 GPM flow into the tub. That means it takes over 20 minuets to fill a tub, so it would be cold before one ever got into it. Called Delta. No response. Asked the plumber " that does not look right, but no idea" . Talked to the major supplier where I got the fixtures. Never heard of it, but were nice enough to give me a new cartridge. Went up to 2.1 GPM. This is the TUB, not the shower. Internet search. All kinds of clearly wrong stuff, but a few leads. I disassembled the cartridge and measured the ports. According to Bernoulli, the fixture will never flow more than about 5 GPM with full on for hot and cold. Delta advertised 6.3 "maximum" @ 60 PSI. So, well sure, it won't flow 6.3. It can't! Misleading advertising.

Found all the tables for pressure drop in PEX systems. Doing the math, I need to increase the inlet regulator at least 5 PSI to make it provide 60 to the fixtures. Plumber set it to 55.

So, I drilled out the exit ports and got up to 2.5. Better, but unusable. Then I read the instructions again. It says to only use copper from valve to tub. Never use PEX. So I followed the instructions. 4.5 GPM with hot only and no longer dribbles from shower head filling the tub. Post valve, the pressure is very very low so just the small restriction of the PEX fittings causes the issue for low flow and the diverter venturi not to work completely.

Why does the "professional" ( in quotes as they clearly not very professional) not know this? It is their JOB to know this.

So I give half a thumb up for the plumbing supplier to stand behind the Delta warrantee. Only half as they knew nothing about flow issues.
A total thumbs down to Delta for ZERO customer support.
A total thumbs down for both ignorant and sloppy work for the plumber.
Oh yea, the Rennai thermostat went bad. First recommended "pro" never responded. Dominion ( installer) menu does not allow you to get to service, just sales, Only the third on the list actually responded and gave me an appointment.

Ironic, I was going to do it all myself, but crawling around under the house is getting harder and harder. I have worked with copper but never PEX so I paid a professional. In the total time involved, I could have done the work myself is less hours than it took to research and correct the mistakes they made. I still have more work adding supports for the pipes under the sinks flopping in the breeze, had to replace where they ran the plastic through the old copper sharp edge supports, and adjusting clamps so the tubes don't twist the shower fixtures.

I still have to re-duct the bath exhaust fans. They just ran the tube into the soffits. No actual vent. I had the old water heater in the crawl space replaced by a vented tankless. Yea, it was an old school taking air from the house for combustion!

I think I have all the electrical code violations fixed. Most were original and should never have passed. A couple look like previous owners. I fixed the structural errors in the framing under the baths that never should have passed and corrected some just plain stupid issues. Clearly the framers did not look at the floorplan for either plumbing or electrical. 2 x 8s notched to 3 inches! Oh yea, one stool was only 13 inches center from the wall. Should never have passed.

 

[Mike Davis]

My home was owner built thirty some years ago, there are many things I would change if I had the time and money.
But it is still better than many new homes I have visited.

 

[junquecol]

When you replumbed with PEX, did you do home runs to a manifold, or like old piping was done? That alone will make a HUGE difference in flow rates. The fittings on 1/2" PEX are closer to 1/4" than half inch inside diameter. As for framing under bath, remember the framers left, and plumber cut the notches.

 

[JimD]

Sorry you had such a nightmare. My house is over 50 years old and it seems like the one previous owner did a lot of stuff himself. A lot of it is OK but some is not. Like two steps on a staircase over 10 inches rise each.

I've hired contractors twice so far changing and updating things. Each time I hire them to get me to finished drywall and then I take over and do the finish plumbing, electrical, carpentry, and painting. Saves money and gives me a good chance to look over what they've done. This meant that I installed the tub surround and did the final cut to length and solder for the tub fill. Not the first time I've done it but making the cut is a little nerve racking, it's hard to measure without the wall in place and you don't have much play. Anyway, having done this I do not see how you even use pex for the tub fill. You have to come out of the valve and go down then make a right angle bend to go out. The end of the horizontal has to have a copper fitting with threads for the tub fill. If you replace the vertical and horizontal copper pieces with cpvc or pex I would think it wouldn't be rigid enough to support the tub fill. My plumber roughed with CPVC (wanted to use PEX but I objected) but put copper on this last little piece. PEX is probably fine but my son had to replumb his house due to use of the predecessor of PEX and I had CPVC in my last house and it worked fine. It is almost as easy to work with.

I think there is a serious chance your plumber either did not know how to solder supply lines, did not have the tools, or did not have the skill. My guy was about my age and certainly knew how to use copper and also could deal with my partially cast iron waste lines. He didn't mind using CPVC but would have charged more for all copper supply lines - even the material is quite expensive. The guys that put in my tankless (same brand as yours) wouldn't use anything but PEX. It's in a little room off my garage where I can easily keep an eye on it and it can't do a lot of damage. But using PEX for that last few inches to the tub is just totally stupid so I think they may not have been capable of doing it right.

 

[ssmith]

Wow - sounds like you've had really bad luck with contractors.

Not sure about others' experiences, but I've seen copper corrode thru in 20 years. The web says PEX will last 50. No reason to doubt it - our last house was plumbed with it and we never had a problem in 21 years. It's also easy to work with - though I'm usually reluctant to work on the pressure side of plumbing, our regulator had to be replaced so I picked up the fittings and pipe and rented a crimper from big orange and fixed it myself. Despite the problems you mentioned, IMO you made a really good choice.

As far as all the other issues mentioned, it's disappointing to hear but poor workmanship seems a common problem both now and in the past. Some may be due to inexperienced DYI work, but we bought a new house last year, and have found numerous problems too. "Pride in your work" seems to be an outdated concept.

 

[Gotcha6]

As for framing under bath, remember the framers left, and plumber cut the notches.

That's why the local inspectors now will not do a framing inspection until all the trade inspections have passed, except the alltrade inspectors, who look at everything..........

 

[tvrgeek]

When you replumbed with PEX, did you do home runs to a manifold, or like old piping was done? That alone will make a HUGE difference in flow rates. The fittings on 1/2" PEX are closer to 1/4" than half inch inside diameter. As for framing under bath, remember the framers left, and plumber cut the notches.

I did a branch replacement. Home run would mean redesign, permit and inspection. That I don't mind, but the delay, and estimate of no water for up to two days after the work was done was not tolerable. It would have literally doubled the cost to an extent I could not afford. Time and money. Direct replacement is classified as a repair. At least in this county.

Now as far as flow drops, there are tables that let you calculate. Drop per 100 feet, drop per fitting etc. It is actually not as bad as one might think. I went through that. A plastic elbow is roughly five feet of pipe. To my outside spigots, I get 7.5 GPM, which is about right for 100 feet equivalent of 1/2 PEX. Main trunk is 3.4 inch. The line drop is not significant compared to the valve restriction which was about 1/8 inch. The tub filler restriction was because it is under almost no pressure. There are WEB calculators that can give you close estimates if you don't mind converting to bar. One spec I can't find is the flow rate of the line regulator but with the spigot rate about as expected, don't think it is an issue. Thought about that as I have seen a cheap automotive fuel line regulator starve a V8.

As far as copper, yes, in some locations, the water can be tough. It can differ house to house on well water. I am on city and it is not acidic. I understand some areas in southern Calif are really bad and some city additives may be tough. The copper tubes to old fixtures were perfect, as were the copper fittings in the old PB. But as there were kinks in tubes, lines in exterior walls, I wanted an additional spigot, (old ones were not even frost free) and redoing the master moving everything a foot or two, it made sense thinking resale in 20 years to have it converted. One story so easy and I am doing the trim repair. So, the design and materials are not to blame for my problems. Workmanship was. If a plumber can't freaking solder, he needs to get a new job. It does take a couple of minuets per joint instead of seconds. A lot of copper failures are also workmanship. Not de-burring the tubes produces cavitation and micro bubbles causing pinholes after 20 or so years. Even though the BORG sells it, CPVC is not approved in this county for new work. They also sell smurf tube which is not permitted either. Actually they sell a lot of sub code stuff. Most in-stock base level garage doors do not meet minimum wind code anywhere.

Improper framing that made the plumber cut the notches was incompetent design or framers not looking at the design. The think they know everything and build SOP without looking at the drawings. That has caused issues with the extreme framing concepts as they won't read the plan. My house has 2 x 12 headers over everything including non-loadbearing interior doors. Why? If they are all the same, they can't screw up. You don't have to read English to read a blueprint, so don't claim it is a immigrant language issue.

Our current inspectors seem far more on the ball than I am told they were 20 years ago.

Like I said, I am no expert, just spent the time researching and all the above is the result of said effort. I expect a licensed professional to have more knowledge than I.

 

[bowman]

I'm on well water & just replaced the last of my copper lines with PEX. House was built in 81, here is the culprit for my water leaks back in September.

 

[Oka]

I am a licensed plumber I do not use pex in my home for a lot of reasons. Main one, when people poison mice/rats the toxin causes them to starve for water, then then eat though the pex in the house and voila' a big mess. Not common but common enough to be an issue.
But if you buy a fixture, there are some that have inserts that can be removed which will all up to 8/gal per min @ 60 psi. If you have the pressure you can raise it to 80. I set my home @ 80 psi.

 

[tvrgeek]

I only use peanut butter and Victor traps. I understand that is a big problem in some places, like NY.

Delta fixtures do not have inserts. They have tiny holes and passages around the pressure equalizer. I don't need more flow than the water heater can flow continuously and I am close to that. I chose Delta for the lifetime finish warrantee as some A-S corroded the finish in just a year, Never use Moen as no replacement cartridge has ever been any good IMHO. Basically, very disappointed in Delta. The valves are all just rubber o-rings. No more the precision ceramics that actually did last forever. Series 17 is a worse design than series 14.
I think I do have 80 PSI or so available. When I bought the house, that was one of the "terrible" problems in the inspection: "Pressure too high" so they put in a regulator and set it to 40. Forget watering the lawn or washing a car. Bought a gauge and cranked it to 55. Now at 60 and by calculation of loss in the PEX, should go to at least 65 to meet the Delta pressure spec. 70 sounds reasonable. Of course, the same inspector failed to notice open junction boxes. incorrectly polarized outlets, cascaded GFI outlets, uneven step heights, porch too high for no railing...

Neal, you might consider having your water tested. Might be a bit acidic. It could be eating the brass and connections of your fixtures. My house I just left in MD was built in '62 and the copper was still fine. ( lead solder properly oxidized and not bleeding due to aggressive water additives.)

 

[JimD]

My house is over 55 years old and the supply lines are copper except for an addition I had done (with CPVC supplies). I have had no issue with the copper lines. I've modified it in a few places and thus cut the line apart and it showed no signs of degradation. Until a few years ago, the house was on a well and the water was acidic. Still it functions fine. There are multiple grades of copper lines, however, and the home centers around me have two. My lines seem to be the thicker copper (with some soft copper thrown in by the previous owner). I used to work with a guy who had multiple leaks in his copper supplies and he doesn't live far away. So I accept it happens. I have also heard of CPVC getting brittle and fracturing but my last house was totally plumbed with it and was fine for the 15 years we were in it.

When my son replaced his flexible plastic supplies (not sure the material) a couple years ago we talked over the alternatives and he decided to use thick wall copper. He did it himself. He knew PEX was cheaper and quicker but I worry about longevity and that probably influenced him. Copper has been used for so many decades with the vast majority of it working well I just think it's the least risky choice. As I'm typing I started to remember we get leaks in copper supplies at church where I volunteer. So another case where it is failing - and that is city water. I don't know the pressure. I guess nothing is completely without risk. (our "fix" is to clamp a little piece of rubber over the leak - I worry about it but they've done it this way for years - it's going to fail, hopefully not catastrophically, we've done the same thing with the 10 inch steel main. No shutoff for the building except at the street. I would never do these things but not my decision)

 

[Willemjm]

Hey, I am reasonably smart, but no genius by any means. When I don't understand something, I do a little research. ( so a lot of time researching) Doing some minor work on my home, built in '92, I find electrical, framing, HVAC, and plumbing code errors as well as just plain bad practice. Why is it that "professionals" can't do it correctly?

A good example of bad, ignorant, or don't care is I just paid a bunch of money to a major plumbing company to re-plumb my house eliminating the old PB tubing in favor of PEX. At the same time, I put in all new Delta fixtures. I would up with only 1.8 GPM flow into the tub. That means it takes over 20 minuets to fill a tub, so it would be cold before one ever got into it. Called Delta. No response. Asked the plumber " that does not look right, but no idea" . Talked to the major supplier where I got the fixtures. Never heard of it, but were nice enough to give me a new cartridge. Went up to 2.1 GPM. This is the TUB, not the shower. Internet search. All kinds of clearly wrong stuff, but a few leads. I disassembled the cartridge and measured the ports. According to Bernoulli, the fixture will never flow more than about 5 GPM with full on for hot and cold. Delta advertised 6.3 "maximum" @ 60 PSI. So, well sure, it won't flow 6.3. It can't! Misleading advertising.

Found all the tables for pressure drop in PEX systems. Doing the math, I need to increase the inlet regulator at least 5 PSI to make it provide 60 to the fixtures. Plumber set it to 55.

So, I drilled out the exit ports and got up to 2.5. Better, but unusable. Then I read the instructions again. It says to only use copper from valve to tub. Never use PEX. So I followed the instructions. 4.5 GPM with hot only and no longer dribbles from shower head filling the tub. Post valve, the pressure is very very low so just the small restriction of the PEX fittings causes the issue for low flow and the diverter venturi not to work completely.

Why does the "professional" ( in quotes as they clearly not very professional) not know this? It is their JOB to know this.

So I give half a thumb up for the plumbing supplier to stand behind the Delta warrantee. Only half as they knew nothing about flow issues.
A total thumbs down to Delta for ZERO customer support.
A total thumbs down for both ignorant and sloppy work for the plumber.
Oh yea, the Rennai thermostat went bad. First recommended "pro" never responded. Dominion ( installer) menu does not allow you to get to service, just sales, Only the third on the list actually responded and gave me an appointment.

Ironic, I was going to do it all myself, but crawling around under the house is getting harder and harder. I have worked with copper but never PEX so I paid a professional. In the total time involved, I could have done the work myself is less hours than it took to research and correct the mistakes they made. I still have more work adding supports for the pipes under the sinks flopping in the breeze, had to replace where they ran the plastic through the old copper sharp edge supports, and adjusting clamps so the tubes don't twist the shower fixtures.

I still have to re-duct the bath exhaust fans. They just ran the tube into the soffits. No actual vent. I had the old water heater in the crawl space replaced by a vented tankless. Yea, it was an old school taking air from the house for combustion!

I think I have all the electrical code violations fixed. Most were original and should never have passed. A couple look like previous owners. I fixed the structural errors in the framing under the baths that never should have passed and corrected some just plain stupid issues. Clearly the framers did not look at the floorplan for either plumbing or electrical. 2 x 8s notched to 3 inches! Oh yea, one stool was only 13 inches center from the wall. Should never have passed.

Don't get me going on what the "Professionals" should know and what they actually do know.

My favorite experience is the guy with 40 years experience, which accounts to around one month's experience repeated 480 times, because they have no interest outside of their comfort zone boundaries.

Your reference to Bernoulli's principle, I wonder how many plumbers would even know what that means, or further how to apply it.

 

[Graywolf]

Not everyone that drives a truck with some plumbing company name on it is a licensed plumber. They work for a licensed plumber. Things have changed in the trades and not for the better. There are no longer city cards for the trades anymore. There is only state level licensing and it takes some work to even sit for that exam.

 

[junquecol]

There is only state level licensing and it takes some work to even sit for that exam.

Been there, done it, having held both a P-2 ( limited to two family residences) and then a P-1 (Unlimited) in working lifetime.

 

[Willemjm]

Not everyone that drives a truck with some plumbing company name on it is a licensed plumber. They work for a licensed plumber. Things have changed in the trades and not for the better. There are no longer city cards for the trades anymore. There is only state level licensing and it takes some work to even sit for that exam.

Yep, when I built my new home Duke Energy had to supply power. The Engineer came out to explain to me cost will be a bit higher than normal. To get to the closest transformer, they had to dig up across the road and some distance down to a neighbor. The switch box sitting on the border of my property had no transformer.

Long story short, I called the developer who informed me, the switch box on my border is meant to be replaced with a transformer, with capacity for both me and my future neighbor. He then gave me the name of the person at Duke who laid out the whole development. It took a number of calls to a number of supervisors, but eventually this got resolved.

The Duke guys came out, installed the transformer and laid the cable to my house. They had no idea of what a transformer capacity rating means, or what the amperage rating was of the cables they were laying. They were just doing what they were told to do, with what stuff was given to them.

 

[Oka]

Bernoulli s principle does not really answer all the interactions when passing through mixing valves, 2nd law , pascals, boyles, plus some others.
The issue is not tho overthink things. Better to reverse pass the outcome you want. You figure things out way faster. The main issue now with a lot of valves is the washerless designs. They make modifying harder

 

[Willemjm]

Bernoulli s principle does not really answer all the interactions when passing through mixing valves, 2nd law , pascals, boyles, plus some others.
The issue is not tho overthink things. Better to reverse pass the outcome you want. You figure things out way faster. The main issue now with a lot of valves is the washerless designs. They make modifying harder

When I was still young and pretty, we did those calculations with a calculator and we had the Cv (flow coefficient) values for the valves and fittings in the system.

Today, the new generation have standardised software doing all they need, most without an understanding of the fundamentals.

 

[tvrgeek]

A plumber by definition is dealing with fluid flow. Water, waste, gas. They had better understand the basic physics of it at a technician level. If they are no longer educated technicians, then we should be paying them idiot stick wages, not technician wages. These guys lack of understanding and lack of education, caused them to make mistakes and be unable to troubleshoot them.

Yea, don't need to work them with a slip-stick like when I was in school. Calculated tables and on-line calculators take the tedium out of it, but a "professional" who installs domestic water lines should understand the basics and should I dare say READ THE INSTRUCTIONS. Delta is not some obscure brand and the lead said he had installed dozens of them. How many people just accept the low flow withthe excuse of the Federal conservation laws ( that apply to the shower head only) and do not know the valve is a terrible design and the installer did it wrong?

FWIW, the Delta is not washer less. It has 9 O-rings in it.

 

[Gotcha6]

FWIW, this thread is in DIY/Home Improvements section and I would venture to say many of our members & readers will benefit from its insights and results.
JMTCW

 

[JimD]

I don't think a plumber should know how to do flow calculations but he should know how to solder copper pipe. To me the big question is why they used the inappropriate material for the valve outlet to the tub.. Reading instructions could have told them what to use, if they didn't already know. I know some of you have had bad experiences with copper and maybe there is another way to do this properly but if the instructions say to use copper and the home owner is not objecting, it seems fairly obvious without a bunch of flow calculations that is what you should do. Might have been lack of skill (hopefully not), might have been lack of material/didn't want to take the time to get the material (only takes maybe 18 inches of pipe and a 90, however), could have even been laziness (didn't want to walk to the truck and get the tools and material).

I've had bad experiences with hiring "professionals" too. I think they did poor work just trying to get done as quickly as possible so they could go to the next job. Didn't seem to be a skill/knowledge thing. I've also hired guys who did a great job.