Under-bench grease traps
Compact traps built to fit the space in your sink cabinet, where your council approves an under-bench trap.
Custom fabrication · Hospitality & food
Stainless grease traps, sized to your kitchen and your council.
Grease traps
Under-bench and above-ground grease traps fabricated in stainless, with removable baffles, gasketed lids and inlet and outlet positions to suit the plumbing you have. Built to the type and capacity your council’s trade-waste team approves.
Indicative pricing · NZD
$1,200
from, + GST
$1,200–$6,000 + GST; in-ground tanks quoted
Price guide & quoted scopeOr call Matt 021 2555 443
- Stainless
- Welded body, grade agreed for the job
- Built to approval
- Type and capacity from your trade-waste approval
- Serviceable
- Lift-out baffles, sealed lids and replacement parts
Choosing a trap
Which grease trap will your council accept?
Your council’s trade-waste team decides the trap type and size for each business. Many prefer a passive trap outside; an under-bench trap is usually approved only where an outside trap won’t work.
| Type | Where it goes | What to know |
|---|---|---|
| Under-bench trap | In the sink cabinet, close to the fixtures | Smaller volume, so it needs more frequent emptying. Usually needs specific approval before building consent |
| Above-ground passive trap | Outside wall, plant room or back-of-house | Larger volume and simpler to service. Some councils, such as Christchurch and New Plymouth, look for 500 litres or more |
| In-ground interceptor | Under a yard, path or driveway | Needs digging and a lid rated for foot or vehicle traffic, so the site details drive the price |
| Converters and automatic units | Under the bench, powered | Proprietary mechanical units. Not something we fabricate, and some councils don’t accept them |
The Building Code acceptable solution (G13/AS2) sets a starting point: at least twice the capacity of the fixtures draining to it, never under 100 litres, and at least 5 litres per seat for cafés and restaurants. Your council has the final say.
02 / Price & scope
Indicative grease trap pricing.
Researched planning estimates in NZD, excluding GST, for a stainless trap supplied to your plumber. Plastic traps in standard sizes cost less; stainless suits approved traps that need a custom size, layout or finish.
Discuss your quote with MattCustom stainless grease trap
From a compact under-bench unit through to a floor-mounted restaurant interceptor.
$1,200from, + GST
$1,200–$6,000 + GST; in-ground tanks quoted
Details to agree for your job
- Fully welded stainless body
- Removable baffles and a gasketed lid
- Inlet and outlet to suit your pipework
- Capacity to match your trade-waste approval
Scope & other costs
Plumbing connection and council trade-waste sign-off are by your plumber; we supply the trap to their spec.
Indicative prices by type
| Trap or part | Indicative price | What changes the price |
|---|---|---|
| Compact under-bench trap | $1,200–$2,200 + GST | Capacity, cabinet space and connection positions |
| Larger under-bench or floor trap | $2,000–$3,500 + GST | Capacity, number of chambers and lid arrangement |
| Above-ground passive trap | $3,500–$6,000 + GST | Approved volume, chambers, access and sampling point |
| In-ground interceptor | Quoted per job | Depth, lid traffic rating and installation |
| Replacement lid, baffle or basket | From $250 + GST per part | Size and number of parts, from your photos and measurements |
What to send for an accurate quote
- The trap type and capacity your council has approved or asked for
- Your plumber’s drawing, with pipe sizes and inlet and outlet positions
- The space available, with photos of the cabinet or location
- The fixtures draining to it and, for cafés, the number of seats
- For replacement parts: photos and measurements of the existing trap and the part
03 / Also built here
Plan the rest of your project.
Explore related products, or talk to the Patumahoe workshop about stainless steel, aluminium and mild steel fabrication.
Floor grates & drains
Channel drains, floor wastes and heavy-duty grates for kitchens, dairies and wash-down floors.
Hoppers & chutes
Infeed hoppers, discharge chutes, funnels and bins for food processing and packing lines.
Machine guards
Mesh enclosures, belt covers and hinged guards made to fit the machinery you already run.
04 / The practical details
Questions about stainless steel grease traps.
What size grease trap do I need?
Your council’s trade-waste team sets it. The Building Code’s acceptable solution starts at twice the capacity of the fixtures draining to the trap, at least 100 litres, and 5 litres per seat for cafés and restaurants, and some councils look for 500 litres or more for a passive trap. Send Matt the approved size and the space you have.
Can I have an under-bench trap instead of an outside one?
Sometimes. Councils usually approve under-bench traps case by case, where an outside trap isn’t practical. Get the approval first; Matt then builds the trap to the approved capacity and to fit your cabinet.
How much does a grease trap cost in NZ?
Standard plastic traps start from several hundred dollars and powered units cost several thousand, plus plumbing. A custom stainless trap is estimated from $1,200 + GST for a compact under-bench unit; see the price guide above for larger traps.
Can you make replacement parts for my existing trap?
Stainless lids, gaskets, baffle plates and strainer baskets can be made from your measurements and photos. Parts for branded mechanical units, such as motors and skimmers, should come from the original supplier.
How often does a grease trap need emptying?
Your trade-waste approval sets the interval. Passive traps are commonly serviced every few months, and smaller under-bench traps more often. A lid that lifts off easily and baffles that come out make that job quicker.
Do you install grease traps?
We fabricate and deliver. A registered plumber connects it and handles the trade-waste approval, and we work to their drawings and connection sizes.
How it works
Spec, quote, fabricate, fit.
01
Spec
We confirm size, materials, the loadings or spec and how it will be used.
02
Quote
It is all priced before any steel is cut, so there are no surprises.
03
Fabricate
Built in the Patumahoe workshop to the agreed spec.
04
Fit
Delivered, fitted or installed and checked over before handover.
Let’s make it fit
Show Matt what you’re working with.
Send through photos, rough measurements and how it’ll be used — we’ll come back with a practical next step and a price.