Perfect waste plumbing?

[markocosic]

How should it be done?

 

 

 

(I've been bitten by waste plumbing in the past...buy the house then find pipes are too small with not enough fall, adapters that seem designed to cause blockages, and fittings that seem to have been made for form over function...if there's even a fitting)

 

 

Above ground waste runs

 

There's no waste plumbing in the house yet. It's single storey for plumbing purposes and sits well above the ground on screws. I'd like all wastes to go down through the floor and into the crawlspace. We can run pretty much any size and fall. Should the worst happen it's all accessible.

 

Have I missed something and this is absolutely daft or do we think it's ok?

 

 

 

The sensible place to put the services (between kitchen and bathroom) was vetoed. Happy wife happy life etc. This leaves us with a 12 metre run from the kitchen to where our underground drains begin.

 

 

 

The list of things feeding it are:

 

(kitchen)

• Dishwasher (assume worst case and it's on the opposite site of a galley to the kitchen sink)
• Kitchen sink with waste disposal

 

(bathroom)

• Handbasin (note: hair)
• Toilet (3/6 litre flush)
• Bathtub with shower over it (note: hair)

 

(utility / craft room)

• Washing machine and tumble dryer condensate
• Utility sink
• Water filter (iron / birm) backwash (note: 30 litres/minute)

 

Q Would it be daft to run a 110 mm "main" from one end of the house to the other? (even where it's just the kitchen feeding into it)

 

Logic being that's going to be difficult to clog and if there's an access at the ends the lot is easily cleaned should it clog.

 

 

Q Would it be better to drop from the kitchen in (for arguments sake) 50 mm then tee into the 110 mm pipe using 50 mm; or would it be better to drop vertically from the kitchen in (for arguments sake) 40 mm (insinkerator outlet size) into a 110 mm stub waste that then runs into the 110 mm main?

 

Logic for the latter being that it exists vertically then doe any turning that could conceivably get clogged in 110 mm.

 

 

Cost difference is pennies in the grand scheme of things and space is not at a premium.

 

 

Things not fed to waste

 

 

Things definitely not feeding it are:

 

 

• Space heating circuit overflow/maintenance discharge
• Ground loop overflow/maintenance discharge

 

(because glycol filled - they're being filled by manual bucket / gravity header tank with the discharge into a large bucket for recycling should they ever need to be drained)

 

Glycol even on the indoor part because with heat off that would well freeze and busting the heat exchangers in the heat pump would be sad.

 

 

Things I'm on the fence about are:

• RO unit for drinking water 
• Quooker tundish 
• MVHR and A/C condensate drains 

 

I'm on the fence about these due to freezing risk. (-10C in winter standard; -20C not uncommon; its a holiday house)

 

In theory there'll be a "switch most stuff off" switch to kill the Quooker and the RO unit. Chance this and run it into the drain? Or...just drop it on the ground? (no trap)

 

The MVHR will be left on a setback to control humidity / smell though. Run the output into a syphon then into the drain? Or...just drop it on the ground? (no trap)

 

 

• Unvented cylinder safety discharge

 

The cylinder built into the heat pump is ridiculous. Stainless, 10 bar working pressure, 9 bar 95 degC temperature/pressure discharge. 

 

I think drop this straight on the ground with no trap too. That's never going to lift except when being tested. (borehole pump couldn't lift it even on dead head) 

 

 

Sink / bath traps - catch hair or don't catch hair?

 

The wife has hair. It's pretty but it crates new life forms when it meets soap. It's always my job to evict them.

 

Do I want to trap this before it heads to the little sewage treatment plant or do I want to encourage it to head there without ever clogging the trap?

 

Depending on the above which plug holes/traps do the best/worst job at trapping hair? This one is bloody fantastic at trapping it much to my annoyance. I'm hoping that the answer is don't trap it and type XYZ trap is better at not trapping it. 🙂