John Lansing
@pipedreaming.bsky.social
Plumbing, building codes, engineering design guides, water and nutrient cycle, architecture, embodied carbon, development, cities, and the international variations of them all
Very rarely in the building codes/ standards world will you see a map with this stark of a contrast.
January 12, 2026 at 6:31 PM
Very rarely in the building codes/ standards world will you see a map with this stark of a contrast.
I suspect the AI slop was attempting to redraw this image (incorrect terminology shown here but no technical issues asides from the super small lavatory drain).
January 11, 2026 at 10:34 PM
I suspect the AI slop was attempting to redraw this image (incorrect terminology shown here but no technical issues asides from the super small lavatory drain).
The sanitary drainage is even worse. There are 3 drainage connections to the tub, 2 installed downstream of the trap and the drainage from the lavatory is draining towards the tub (or the fitting is backwards). There’s a tiny 2 inch connection to the WC into the 1/4 bend. Zero drawing perspective.
January 11, 2026 at 10:29 PM
The sanitary drainage is even worse. There are 3 drainage connections to the tub, 2 installed downstream of the trap and the drainage from the lavatory is draining towards the tub (or the fitting is backwards). There’s a tiny 2 inch connection to the WC into the 1/4 bend. Zero drawing perspective.
Let’s start with the water supply. The hot water from the lavatory is running to the shower thru the tub faucet supply while the HW/CW supplying the shower doesn’t go anywhere.
January 11, 2026 at 10:29 PM
Let’s start with the water supply. The hot water from the lavatory is running to the shower thru the tub faucet supply while the HW/CW supplying the shower doesn’t go anywhere.
Something like this, which can be fitted with an accessible ramp.
January 11, 2026 at 7:56 AM
Something like this, which can be fitted with an accessible ramp.
I’m guessing the plan is use
existing mass-produced portable restrooms, common at construction sites and temporary event spaces.
existing mass-produced portable restrooms, common at construction sites and temporary event spaces.
January 11, 2026 at 7:56 AM
I’m guessing the plan is use
existing mass-produced portable restrooms, common at construction sites and temporary event spaces.
existing mass-produced portable restrooms, common at construction sites and temporary event spaces.
Here’s the impact of negative pressure on the water seal of a trap. Air is being pulled from the indoor air side of the trap into the drainage system.
January 11, 2026 at 5:16 AM
Here’s the impact of negative pressure on the water seal of a trap. Air is being pulled from the indoor air side of the trap into the drainage system.
The best solution is a small, high temperature tank (140°F/60°C) with a distribution mixing valve at the tank, which is located near the bathroom (short distance to fixtures).
January 9, 2026 at 11:48 PM
The best solution is a small, high temperature tank (140°F/60°C) with a distribution mixing valve at the tank, which is located near the bathroom (short distance to fixtures).
For more detailed context: this is a check valve for the point-of-use thermostatic mixing valve. Because the cold water and hot water connect to each other at the mixing valve, a check valve is needed to prevent crossover flow since the hot water is typically at a slightly higher pressure.
January 9, 2026 at 11:28 PM
For more detailed context: this is a check valve for the point-of-use thermostatic mixing valve. Because the cold water and hot water connect to each other at the mixing valve, a check valve is needed to prevent crossover flow since the hot water is typically at a slightly higher pressure.
Here’s a photo I took of one of the failed valves stuck in the open position at the restroom lavatories on a school renovation project causing urinals to flush with steaming hot water.
January 9, 2026 at 11:21 PM
Here’s a photo I took of one of the failed valves stuck in the open position at the restroom lavatories on a school renovation project causing urinals to flush with steaming hot water.
Tanner Springs is a mini version of this and Portland needs many more!
January 9, 2026 at 7:05 PM
Tanner Springs is a mini version of this and Portland needs many more!
Denmark really does have incredible tasting tap water though.
January 8, 2026 at 10:00 PM
Denmark really does have incredible tasting tap water though.
Keeping hot water hot and not just “warm” is the main idea, because shower temperatures or handwashing temperatures are ideal for legionella growth.
January 8, 2026 at 8:53 PM
Keeping hot water hot and not just “warm” is the main idea, because shower temperatures or handwashing temperatures are ideal for legionella growth.
Denmark also has some of the highest Legionnaires’ disease cases in Europe, a disease with the primary source of infection being domestic hot water systems and cooling towers in buildings.
January 8, 2026 at 8:53 PM
Denmark also has some of the highest Legionnaires’ disease cases in Europe, a disease with the primary source of infection being domestic hot water systems and cooling towers in buildings.
There are two main benefits that come to mind with this approach. The utility box for clothes washing machines is always mounted to the framing, which often places the drainage piping in an awkward configuration with the trap. This gets even worse for multistory residential due to the stack/vent.
January 7, 2026 at 6:25 AM
There are two main benefits that come to mind with this approach. The utility box for clothes washing machines is always mounted to the framing, which often places the drainage piping in an awkward configuration with the trap. This gets even worse for multistory residential due to the stack/vent.
The drains for washing machines in Asia connect into the floor rather than the wall, using special floor drain adapters like this.
January 7, 2026 at 6:25 AM
The drains for washing machines in Asia connect into the floor rather than the wall, using special floor drain adapters like this.
“It is now well understood that a very large proportion of the deaths from diphtheria, typhoid fever, and cerebro-spinal meningitis which occur annually in this and other cities, are due wholly to the poisonous effects of sewer-gas” [Note to reader: this was absolutely not true!]
January 6, 2026 at 7:17 PM
“It is now well understood that a very large proportion of the deaths from diphtheria, typhoid fever, and cerebro-spinal meningitis which occur annually in this and other cities, are due wholly to the poisonous effects of sewer-gas” [Note to reader: this was absolutely not true!]
“…the duty of protecting the public from sewer gas is even more imperative just at present than that of preventing the building of houses without tire escapes; since, where one person perishes from fire, it is no exaggeration to say that a hundred are killed by sewer-gas.”
January 6, 2026 at 7:17 PM
“…the duty of protecting the public from sewer gas is even more imperative just at present than that of preventing the building of houses without tire escapes; since, where one person perishes from fire, it is no exaggeration to say that a hundred are killed by sewer-gas.”
Move over Costco Condos, we’re doing Library Lodges
January 6, 2026 at 4:50 AM
Move over Costco Condos, we’re doing Library Lodges
New York and New Jersey are best understood with these graphics, which you will notice matches what is in the Brazilian plumbing code (copied here and covered at 1:46 of Julia’s video).
January 4, 2026 at 9:18 PM
New York and New Jersey are best understood with these graphics, which you will notice matches what is in the Brazilian plumbing code (copied here and covered at 1:46 of Julia’s video).
IPC: Connection clearance zone is 10 diameters downstream of the stack (3’-4” for a 4 inch stack). This applies to all drainage stacks and isn’t specific to detergent foaming. No connection clearance zones specified above the stack base.
January 4, 2026 at 9:18 PM
IPC: Connection clearance zone is 10 diameters downstream of the stack (3’-4” for a 4 inch stack). This applies to all drainage stacks and isn’t specific to detergent foaming. No connection clearance zones specified above the stack base.
Just to highlight how much variability there is, here are some examples:
UPC: 8 ft upstream and downstream of the stack base and offsets (San Francisco modified this to 10 ft in the local adoption of the UPC).
UPC: 8 ft upstream and downstream of the stack base and offsets (San Francisco modified this to 10 ft in the local adoption of the UPC).
January 4, 2026 at 9:18 PM
Just to highlight how much variability there is, here are some examples:
UPC: 8 ft upstream and downstream of the stack base and offsets (San Francisco modified this to 10 ft in the local adoption of the UPC).
UPC: 8 ft upstream and downstream of the stack base and offsets (San Francisco modified this to 10 ft in the local adoption of the UPC).
Some more recent investigations (27 years ago) at Heriot-Watt University shed more insight on this subject but the results were still far from providing effective generalized design guidance for design and installation.
January 4, 2026 at 9:18 PM
Some more recent investigations (27 years ago) at Heriot-Watt University shed more insight on this subject but the results were still far from providing effective generalized design guidance for design and installation.
The issue of detergent foam was investigated by the Building Research Station (🇬🇧) and CSTC (🇧🇪) but no comprehensive study was conducted by NIST, which has left very inconsistent requirements throughout the US, and likely partially explains why this is missed on so many projects where it’s required.
January 4, 2026 at 9:18 PM
The issue of detergent foam was investigated by the Building Research Station (🇬🇧) and CSTC (🇧🇪) but no comprehensive study was conducted by NIST, which has left very inconsistent requirements throughout the US, and likely partially explains why this is missed on so many projects where it’s required.
NBS still exists today as NIST but the housing division and plumbing work has been severely impacted by austerity, which was taken to another level under this administration.
January 4, 2026 at 5:37 PM
NBS still exists today as NIST but the housing division and plumbing work has been severely impacted by austerity, which was taken to another level under this administration.