SNZ Plumbing Estimating

04/08/2026

Tempering Valves vs TMVs: When 45°C Is Mandatory (Class 3 & NDIS SDA)

Tempering Valves vs TMVs: When 45°C Is Mandatory (Class 3 & NDIS SDA) In Australian plumbing, tempering valves and thermostatic mixing valves (TMVs) both blend hot and cold water to prevent scalding, but they are not interchangeable — especially in Class 3 buildings (residential care, group homes, supported accommodation, NDIS Specialist Disability Accommodation). Key Differences...

12/07/2026

How to Calculate Bedding and Spoil for a Pipe Trench

The takeoff is done. You know you have 25 metres of DN100 here and 40 metres of DN150 there....

The takeoff is done. You know you have 25 metres of DN100 here and 40 metres of DN150 there. Now comes the question your takeoff software will not answer: how do you calculate the spoil coming out of that trench, and how many tonnes of bedding do you need to order? Here is the method,

06/07/2026

Top 5 Estimating Mistakes Plumbers Make (And How to Avoid Them)

Top 5 Estimating Mistakes Plumbers Make (And How to Avoid Them) SNZ Plumbing Estimating – Avoid Costly Callbacks & Compliance Fails in 2026…...

Avoid under-quoting TMVs, forgetting ORGs, missing fire collars, wrong hot water sizing & skipping isolation valves. Top mistakes in Australian plumbing estimates 2025.

14/06/2026

Rainwater Tanks for New Homes – BASIX Compliance & Sizing 2025

Rainwater Tanks for New Homes – BASIX Compliance & Sizing 2025 Rainwater tank BASIX requirements NSW 2025 – rainwater reuse toilets laundry Sydney, rainwater tank size calculator & national rules explained…...

Rainwater tank BASIX requirements NSW 2025 – rainwater reuse toilets laundry Sydney, rainwater tank size calculator. National rules AS/NZS 3500.1 Clause 9 & labelling/backflow explained.

01/06/2026

Backflow Prevention: When RPZD Is Required & Tundish Setup

Backflow Prevention: When RPZD Is Required & Tundish Setup PCA Part B5 explained – RPZD for high-hazard cross-connections + correct tundish discharge (trap vs in-wall) for safe, compliant installations…...

PCA Part B5 & AS/NZS 3500.1 Clause 8 – when RPZD is mandatory for high-hazard connections. Correct tundish setup (trap vs in-wall) for RPZD relief discharge in Sydney.

17/05/2026

Fire Hose Reels & Hydrants – When Required in Class 2 & 3 Buildings

Fire Hose Reels & Hydrants – When Required in Class 2 & 3 Buildings NCC E1D3 fire fighting equipment explained – fire hose reels Class 3 dwelling, hydrant requirements apartments Sydney, single-storey exemptions 2025/2026 Fire hose reels and hydrants are not always required in residential buildings, but getting this wrong can lead to major defects, delayed occupancy certificates and costly rectification....

Fire hose reels Class 3 dwelling explained – NCC E1D3 fire fighting equipment exemptions for single-storey group homes & NDIS SDA. Hydrant requirements apartments Sydney 2025.

17/05/2026

Fire-Rated Penetrations for Plumbers – Collars, Wraps & Mastic Basics

Fire collars plumbing penetrations explained: NCC Volume One Specification 13 – plastic vs metal pipes, one collar vs two, wraps/mastic basics. Trafalgar FyreCOLLAR Sydney picks 2025.

04/05/2026

Pipe Bedding & Trench Width: The 75 mm Rule & Why It Matters

Pipe Bedding & Trench Width: The 75 mm Rule & Why It Matters AS/NZS 3500.2:2025 Clause 12.2 explained – 75 mm below pipe, haunch to springline, minimum trench width OD + 200 mm – avoid sagging, cracking & costly repairs Poor pipe bedding is one of the leading causes of long-term drainage failures in Australian homes and commercial buildings — sagging pipes, blockages, root intrusion, and cracks that lead to leaks and expensive rectification orders....

AS/NZS 3500.2 Clause 12.2 & Figure 5.4.4: 75mm bedding below pipe, haunch to springline, minimum trench width OD + 200mm. Avoid sagging, cracks & drainage failures.

12/04/2026

Grease Traps for Commercial Kitchens – Sizing & Compliance 2025

Grease Traps for Commercial Kitchens – Sizing & Compliance 2025 Grease trap sizing commercial kitchen, grease interceptor AS/NZS 3500, commercial kitchen plumbing Sydney – full guide for NSW 2025 Grease traps (also called grease interceptors) are mandatory in most commercial kitchens in Australia to prevent fats, oils and grease (FOG) from blocking sewers and causing environmental damage. Incorrect sizing or installation leads to frequent blockages, council fines, Sydney Water penalties and expensive clean-outs....

Grease trap sizing commercial kitchen using AS/NZS 3500.2 Table 4.8.1. Mandatory requirements, common mistakes & Sydney Water rules for restaurants, cafés & takeaway fit-outs 2025.

06/04/2026

Rainwater Reuse: Toilets, Laundry & Garden Taps – National Rules & BASIX Wins in 2026

Rainwater Reuse: Toilets, Laundry & Garden Taps – National Rules & BASIX Wins in 2026 AS/NZS 3500.1 Clause 9 explained – labelling, backflow, mandatory requirements for new homes & how to win BASIX points Rainwater harvesting and reuse is one of the most cost-effective ways to cut water bills and meet sustainability targets in new Australian homes. Whether you're reusing rainwater for toilets, laundry/washing machines, garden taps, outdoor taps, or car washing, the rules are national and clear — but many plumbers still get caught on labelling, backflow, or council/BASIX requirements....

AS/NZS 3500.1 Clause 9 explained: rainwater tanks for toilets, laundry, washing machines & garden taps. National labelling, backflow rules & how to win BASIX points in NSW new homes.