Plumbing

I'm running a 3-inch main drain and a 2-inch branch under a slab. What slope do I need on each?

How deep is the water seal in a P-trap supposed to be, and why does it matter if it's deeper?

How far can I run a 1-1/2 inch lavatory trap arm before it has to hit a vent? What about a 2-inch trap arm for a kitchen sink?

Give me the rules for the T&P relief valve discharge pipe on a tank water heater.

I'm setting a 50-gallon electric heater in a second-floor laundry closet. What are the requirements for the drain pan?

House has 95 psi static at the hose bib. Do I need a pressure reducing valve, and what else changes once I put one in?

Repiping from old galvanized to copper in a 1960s house. How am I supposed to make the transition where copper meets the remaining galvanized?

Walk me through solvent-welding a 3-inch PVC DWV joint the right way.

Which fittings can I use for a horizontal-to-horizontal change of direction on a drain line, and where is a sanitary tee actually allowed?

How tall does a washing machine standpipe need to be and what size trap?

Hanger spacing: how often do I have to support horizontal PVC DWV, 1/2 inch copper, 3/4 inch PEX, and cast iron?

What kind of valve is required on a tub/shower, and what temperature is it supposed to be set to?

Roughing in a toilet in a small half bath. What clearances do I have to hold?

Single-family house: two full baths (1.6 gpf toilets, lav, tub), a kitchen sink with disposer and dishwasher, and a washer. Can the building drain be 3 inch at 1/8 in/ft? Show the DFU math.

Building a tile shower on a mud bed with a PVC pan liner. What are the liner rules and how is the liner tested?

What's the right way to sweat a 3/4 copper joint so it doesn't leak, and what's the trick when there's still water in the line?

Homeowner says the T&P valve on the water heater drips every evening and they've already replaced it twice. Pressure at the hose bib is 65 psi. What's going on and what do I do?

Do outside hose bibs need any kind of backflow protection?

When can I use an air admittance valve (Studor vent) instead of running a vent through the roof, and what are the installation rules?

Where am I required to put cleanouts on a residential building drain and sewer, and how big?

I'm replacing a sewer line in a front yard in Clay County, Florida. Do I have to call anything before I dig, and how far ahead?

How deep does a building sewer and the water service have to be buried in Florida?

Where can I terminate a plumbing vent through the roof, and how close can it be to a bedroom window?

What test does the inspector want on a new water supply rough-in, and can I use air?

DWV rough inspection on a two-story house in Jacksonville. What head of water does the inspector expect on the water test, and is it the same as the model IPC?

Installing a gas tank water heater in an attached garage. What does code say about height and the pan?

Customer wants me to tee a new irrigation system off the house service. What backflow device is required and do I need to get it tested?

Master bath is on the far end of the house from the water heater, about 70 feet of pipe. Is there a code limit on how far hot water can run?

Apprentice roughed in a bathroom lav: 1-1/2 inch P-trap, trap arm runs 9 feet horizontally at 1/4 per foot to a sanitary tee on the 2-inch vent/stack. He says it's fine because it's 'sloped right and vented.' What's the problem?

Under a slab, a helper joined a 3-inch horizontal branch into the 4-inch horizontal building drain with a 4x3 sanitary tee laid on its back, because 'that's what fit.' Inspection is tomorrow. What's wrong?

Handyman replaced a 40-gallon gas heater in a closet. To reach the floor drain he ran the T&P discharge up over a shelf and down in 1/2 inch PEX with a threaded adapter on the end, and tied it into the drain with a glued fitting. Heater works. What did he get wrong?

On a new 50-gallon gas atmospheric heater, the plumber crimped 3/4 PEX directly onto the heater's top nipples with brass PEX adapters and ran it straight to the manifold. Owner wants to know if that's OK.

Tile guy built a mud-set shower: laid the PVC liner flat on the plywood, packed the mud bed on top, screwed the liner to the curb 1/2 inch above the curb top, and slathered thinset around the drain base to 'seal it.' It flood tested fine. Why will this shower fail?

Slab-on-grade addition in Florida. The plumber ran the 3/4 copper water lines through the slab pour with no sleeve, poured monolithic, then stubbed up in the wall. What's coming?

Remodel: kitchen island sink vented with an AAV under the cabinet, bathroom group vented with an AAV in the attic sitting on the branch under the blown insulation, and the old roof vent was capped because 'we don't need it now.' Inspector's coming. What fails?

Cold morning, 42 degrees. Helper glued twelve 4-inch PVC sewer joints with cement only (no primer, 'it's the all-in-one kind'), didn't twist them, and 10 minutes later put 30 psi of air on the line to test it. Where's this going?

Sewer replacement: 60 feet of 4-inch PVC from the house to the tap at the street, laid at 1/16 per foot because the tap was shallow, joined to the old cast iron stub with an unshielded Fernco rubber coupling, no cleanout at the house, and backfilled with the excavated limerock and chunks of old concrete. Inspector already passed it on a drive-by. What's wrong and what happens later?

Bath remodel: contractor set the closet flange 1 inch below the new tile floor and stacked two wax rings to make up the gap, and the flange centerline sits 13 inches from the new vanity. He says toilets get set like this all the time. What's wrong?

Restaurant build-out: the plumber hard-piped the 3-compartment sink with a P-trap straight into the branch feeding the grease interceptor, ran the ice machine drain and the prep sink directly into the sanitary line with traps, and set the walk-in cooler floor drain with a trap inside the box. Health and plumbing inspection is Friday. What gets flagged?

Laundry room: the plumber cut the washer standpipe off at 12 inches above the trap to fit under the counter, used a 1-1/2 inch P-trap, and pushed the washer hose into the pipe with a rubber grommet so 'it wouldn't splash.' Washer supply valves are plain quarter-turn ball valves with no arrestors. Problems?