Yes, pouring a concrete laundry tub surround is something a capable DIYer can tackle safely in New Zealand. It's a relatively small concrete pour, but it does sit in a wet area, so waterproofing, drainage, and plumbing connections need careful attention — some of which is legally restricted work.
What Is a Concrete Laundry Tub Surround?
A concrete laundry tub surround (sometimes called a laundry bench or trough surround) is a cast concrete structure that supports and frames a laundry tub or trough. It can be purely decorative and structural, or it can incorporate a formed basin. The most common DIY version involves building a timber or plywood formwork frame, pouring a concrete mix, then finishing and sealing the surface.
Does It Need a Building Consent?
In most cases, a simple laundry tub surround does not require a building consent under Schedule 1 of the Building Act 2004, as it is typically minor building work. However, if you are making changes to plumbing, drainage, or the structure of your home, consent requirements can change. Always check with your local council before starting — rules vary by region and project scope. You can find guidance on consent exemptions at MBIE Building Performance.
Planning Your Surround
Before you mix a single bag of concrete, spend time on planning:
- Measure carefully — account for the tub dimensions, wall clearances, and the height that suits your household (standard laundry bench height is around 900 mm).
- Check the floor — make sure the existing floor can handle the added weight of a concrete structure. Concrete is heavy; a typical small surround can weigh 80–150 kg or more.
- Consider drainage — the surround area should slope slightly toward the tub or a floor waste to prevent water pooling.
- Think about waterproofing — laundry areas may be subject to wet area requirements under the NZ Building Code — check with your council or a licensed building professional for the applicable clause, as E3 relates to internal moisture in areas such as bathrooms and showers, so surfaces that contact water must be waterproofed.
What You'll Need
- Timber or plywood for formwork
- Reinforcing mesh or rod (for larger pours)
- Bagged concrete mix (available from Bunnings or Mitre 10) or ready-mix if the volume warrants it
- A spirit level, trowels, and a float
- Waterproofing membrane or sealer suitable for wet areas
- Safety gear: gloves, safety glasses, and waterproof boots — wet concrete is caustic and can cause serious skin burns
Step-by-Step Overview
1. Build Your Formwork
Construct a sturdy timber frame in the shape of your surround. Brace it well — concrete exerts significant pressure when wet. Seal internal joints with silicone or tape to prevent leaks.
2. Add Reinforcement
For any section thicker than about 75 mm, or where the surround will carry load, add reinforcing mesh. This prevents cracking over time.
3. Mix and Pour
Use a general-purpose bagged concrete mix for small pours, following the manufacturer's water ratio instructions exactly. Over-watering weakens concrete significantly. Pour in layers if needed, and use a rod or trowel to eliminate air pockets.
4. Finish the Surface
Once the concrete has started to set (but is not fully hard), use a steel float for a smooth finish or a wooden float for a more textured surface. Cure the concrete slowly — keep it damp and covered for at least 3–7 days to achieve proper strength.
5. Waterproof and Seal
This is a critical step in a laundry wet area. Apply a wet-area waterproofing membrane to all surfaces that will contact water, paying special attention to junctions between the surround and walls. Products from Ardex or Sika are well-regarded for this application. Once cured, apply a concrete sealer to protect the finish.
6. Tiling (Optional)
Many homeowners tile over the concrete surround for a more finished look and easier cleaning. Use a tile adhesive and grout rated for wet areas.
Plumbing Connections — Restricted Work
This is where DIY has a hard legal boundary in New Zealand. Connecting or modifying water supply pipes or waste/drainage fittings is restricted plumbing and drainlaying work under the Plumbers, Gasfitters, and Drainlayers Act 2006. This work must be carried out by a licensed tradesperson registered with the Plumbers Gasfitters & Drainlayers Board.
As a homeowner, you can generally:
- Disconnect and reconnect a tap or fitting on the same thread (like-for-like replacement in some circumstances)
- Do preparatory work such as building the surround itself
You cannot legally:
- Extend or modify water supply pipework
- Alter waste or drainage connections
- Install new fixtures that require new plumbing connections
If in doubt, hire a licensed plumber. You can find qualified local plumbers on tradedirectory.co.nz.
Safety Notes
- Wet concrete is caustic — always wear gloves, eye protection, and waterproof footwear. Prolonged skin contact can cause chemical burns.
- Work in a well-ventilated area.
- Dispose of unused concrete mix and washwater responsibly — never pour it down a drain or into a waterway, as it is harmful to the environment.
- Check WorkSafe NZ for guidance on safe handling of construction materials.
When to Call a Professional
Consider hiring a qualified concreter or builder if:
- The surround is large or structurally complex
- You are unsure about waterproofing requirements under the NZ Building Code
- The project involves any changes to plumbing or drainage (always use a licensed plumber)
- You want a guaranteed, high-quality finish
A licensed tradesperson will also be able to advise whether your project needs a building consent. Find experienced local concreters and builders at tradedirectory.co.nz.
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