c/commercial-plumbing

I spent $500 on a fancy pipe inspection camera and barely use it

Everyone says you need one for commercial jobs, but honestly, most of our work is in new builds where the plans are clear. It sat in the truck for a year after a single job at a hotel in Phoenix. What specific situations do you guys actually find them useful for?

Can we talk about the wrong way to size a grease interceptor for a new restaurant?

I keep seeing plumbers in my area just go by the fixture count, but after a job in Springfield last month where we had to replace a 40-gallon unit with a 75-gallon one after it failed inspection, I learned you absolutely have to factor in the sink's actual flow rate and the local code's waste accumulation time, so has anyone else had an inspector fail a unit for being under-sized?

Just had a main line clog shut down a food court during lunch rush

I was at the Westgate Mall in Springfield last Tuesday when a call came in about three sinks backing up at once. The floor drain in the kitchen area was already overflowing with gray water. We ran a camera down the 6-inch main and found a solid mass of congealed grease and wet wipes about 40 feet in. Had to bring in a jetter with a special cutting head to break it up, took us almost four hours. Anyone else had to deal with a combined grease and wipe blockage in a shared line?

Hot take: I tried using a drain snake meant for a kitchen sink on a 4-inch floor drain in a strip mall.

The thing just coiled up inside the big pipe and came back out looking like a metal pretzel. Had to call a guy with a real jetter after wasting an hour. Anyone ever try something that was clearly the wrong tool for the job and it just laughed at you?

Vent: A big grease interceptor in a local diner backed up on a Saturday morning rush

The whole floor drain system flooded because someone had been dumping coffee grounds down the sink for weeks. We had to shut down their kitchen for three hours to snake and jet the main line. Has anyone found a good way to get owners to actually train their staff on what not to put down drains?

Watching a crew try to use residential PEX for a 4-story office building in Tempe

The pressure drop across those long runs will be a nightmare in two years, and I've seen it fail inspection three times now. Anyone else had to fix this after the fact?

Rant: I thought those new 'smart' flush valves were just a gimmick until I saw the water bill at a 40-unit office building drop 22%.

The water pressure change at the old library on Main Street was huge

We redid the main supply line for the city library last month, switching from the original 1950s galvanized pipe to a new 2-inch PEX system. Before the swap, the third-floor restrooms had maybe 20 psi, and now they're pushing a solid 65. What's the biggest pressure jump you've seen after a repipe job?

A building inspector in Tacoma told me my backflow preventer install was a 'lawsuit waiting to happen'

He pointed out a single missing air gap on a hospital's medical gas line I'd just signed off on. Anyone else ever had a close call with a code detail that big?

My boss told me to always use a torque wrench on those big 4-inch flanges

I ignored him once on a hospital job and a gasket blew after six hours. Anyone else have a rule they learned the hard way?

Overheard a contractor say they never use dielectric unions on commercial water heaters

I was picking up a new circulator pump at the supply house in Tacoma yesterday and heard a guy telling another plumber he skips dielectric unions on big commercial heaters to save time. He said the brass nipples and steel tanks are fine without them. That made me stop and think, because I've seen what happens after a few years without that break. Has anyone else run into this mindset on bigger jobs, and what's your take on cutting that corner?

Finally swapped from standard Teflon tape to the blue Monster Seal stuff on a big apartment job.

Had zero leaks on 200+ gas fittings last week, the thicker seal just seats way better. Anyone else find a go-to thread sealant for gas lines they trust?

A client's comment about my pipe sizing method made me rethink it

I was running the numbers for a new restaurant in Austin, using my usual method for sizing the main water line. The owner, who used to be an engineer, looked it over and said, 'Your peak flow estimate is too low, you're not counting the three industrial ice machines running at the same time.' He was right, I was just using a standard table. I redid the math with his specific equipment schedule and had to go up a full pipe size. Has anyone else had a client catch a detail you missed on a plan review?

Showerthought: I just saw the difference between a basic and a full grease interceptor cleanout

We had a restaurant client in Omaha with a slow drain in the kitchen line. The first crew just snaked the main line and called it good, but it backed up again in two weeks. I went out myself and insisted on a full interceptor pump and scrape. We pulled out over 40 pounds of solid grease and food waste that the snake just pushed past. The line has been clear for six months now. Has anyone else had a job where the 'quick fix' just made the next visit worse?

I finally looked up the water pressure code for a new strip mall job

I was reading the local building code for a project in Riverside and saw that commercial kitchens need a minimum of 80 PSI at the fixture, which is way higher than I thought. My supplier said it's to handle multiple appliances running at once without a drop. Has anyone else had to upgrade a whole main line just to meet that spec?

I was using the wrong size pipe cutter on copper for years until a job in Cincinnati

The foreman saw my rough cuts and asked if I was trying to make extra work for the solder crew. I switched to a 4-inch cutter and the difference was instant. Anyone else have a simple tool swap that fixed a basic mistake?

So last week I found a rubber duck in a 4-inch main line at a Phoenix office tower

Honestly, it was lodged right before a backflow preventer, and the property manager swore the building was 'duck-free'. Has anyone else pulled something truly bizarre out of a commercial system?

Serious question, has anyone else tried using a 2-inch PVC for a main drain in a small strip mall?

I figured it would handle the flow from three sinks and a mop closet, but it backed up during the lunch rush on day two. The plumber I called said, 'You can't use a straw for a fire hose.' Anyone have a better rule of thumb for sizing these things?

Serious question, has anyone else tried using a 2-inch PVC for a main drain in a small strip mall?

Everyone told me to go 3-inch minimum, but the specs and flow calcs said 2-inch was fine for this 3-unit spot in Tampa. Six months later, zero issues and saved the client about $800 on materials. Am I just lucky or are we over-sizing drains by default?

PSA: My old boss told me to ignore the grease trap maintenance schedule at a new diner job

He said the monthly pump-out was a waste of money and to just wait until it smelled. Six months into the lease, the entire line from the kitchen to the main backed up on a Saturday night. The emergency call plus the city fine for the violation was over $2,500. The health inspector showed up Monday morning because of the smell complaint from next door. Now I set a calendar alert for the 15th of every month without fail. Anyone else get burned by skipping trap service?

The $800 backflow preventer that saved a strip mall job

We had a job for a small strip mall where the city inspector flagged the old backflow setup. I bit the bullet and put in a new RPZ assembly, cost about $800 with parts and my time. It felt like a lot upfront, but it passed inspection first try and the owner was happy. If we had tried to patch the old one, we would have failed and been back out there for another full day. That one device kept the whole project on schedule. Anyone else had a piece of gear that seemed expensive but was totally worth it in the end?

I was sure the old cast iron drains in that 1950s school were fine, but a camera inspection changed my mind.

PSA: An old timer at a supply house in Tacoma showed me a trick for stubborn union nuts.

I was fighting a 3-inch union on a boiler swap last Thursday and this guy saw me struggling, walked over, and said 'heat the female side, not the nut, with a torch for ten seconds'. It broke free instantly. Anyone know why that works better than just cranking on the wrench?

Just tallied up the total linear feet of 4 inch PVC we ran for a new school project. It was over 2,800 feet. That number feels... huge.

That time a clogged grease interceptor shut down a whole kitchen for three days

Got called to a new restaurant in Phoenix last month for a slow drain in the main kitchen line. Figured it was a simple clog, maybe an hour tops. Opened the cleanout and found a solid plug of grease and food waste that went back almost 15 feet. The grease interceptor was completely full and had been bypassed by the previous installer. We had to pump out the interceptor, then run a heavy duty jetter with a cutter head down the 4 inch line three separate times to break it all up. What I thought was a quick fix turned into a full three day job. The owner was furious because he had to close for lunch service. Has anyone else had a grease trap issue blow up into a multi-day nightmare?