Fitting a threshold strip between two different floor types — say, timber or laminate meeting tiles, or carpet meeting vinyl — is a satisfying DIY job most homeowners can tackle in an hour or two. The key is choosing the right type of strip for your situation, measuring carefully, and fixing it securely so it stays put underfoot for years to come.
Why Threshold Strips Matter
Beyond looking tidy, a threshold strip serves a practical purpose: it bridges the height difference between two floor surfaces, protects exposed edges from chipping or fraying, and creates a clean visual transition. Without one, edges can lift, trip hazards develop, and moisture can sneak underneath flooring — a real concern in New Zealand's varied climate, particularly in wetter regions or homes subject to the Healthy Homes Standards.
Choosing the Right Type of Strip
Not all threshold strips are the same. The main types you'll find at Bunnings or Mitre 10 include:
| Strip Type | Best Use |
|---|---|
| T-bar / T-mould | Two floors at the same or similar height (e.g. laminate to laminate, or laminate to tile) |
| Reducer strip | One floor higher than the other (e.g. thick timber to thin vinyl) |
| End cap / carpet bar | Flooring that meets a vertical surface or carpet edge |
| Overlap / cover strip | Covering an existing edge where you can't get underneath |
| Carpet-to-tile bar | Grips carpet on one side, sits flush against tile on the other |
Materials vary too — aluminium, stainless steel, solid timber, and laminate-matched profiles are all common. For wet areas like bathrooms or laundries, choose an aluminium or stainless option to avoid swelling or rust.
Tools and Materials You'll Need
- Tape measure and pencil
- Hacksaw or mitre saw (for cutting metal or timber strips)
- Drill and appropriate drill bits
- Screwdriver or impact driver
- Hammer (for snap-down or nail-in strips)
- Appropriate fixings: screws, plugs, or adhesive (check manufacturer's instructions)
- Safety glasses
- Silicone sealant (optional, for wet-area installations)
Step-by-Step Installation
1. Measure the Doorway or Transition Gap
Measure the width of the opening accurately. If the gap isn't perfectly straight, measure at both ends and the middle. Cut your strip to length using a hacksaw or mitre saw — always cut from the decorative face side down to reduce chipping on laminate or timber strips.
2. Check the Height Difference
Use a straightedge across both floor surfaces to gauge the height difference. This confirms whether you need a flat T-bar, a reducer, or another profile. Most reducer strips accommodate a difference of up to around 10–15 mm, but check the product specs.
3. Prepare the Substrate
Clear away any old adhesive, staples, or debris from the transition zone. If you're fixing into a concrete subfloor — common in NZ slab homes — you'll need to drill and plug before screwing. For timber subfloors, direct screwing is usually fine. Make sure the subfloor is flat and solid; any flex here will cause the strip to rock and eventually work loose.
4. Fix the Base Track (if applicable)
Many modern threshold strips use a two-part system: a base track screws to the floor, and the decorative cap snaps or slides over it. Position the base track centrally over the gap, pre-drill your fixing holes, and screw it down firmly. Space fixings no more than 300 mm apart for a secure hold.
5. Snap or Screw the Cover Profile
Once the track is fixed, press or slide the cover profile into place. For snap-down types, use a rubber mallet or a block of timber to tap it home evenly along its length — avoid hitting it directly with a metal hammer, which can dent or crack the profile.
6. Finishing Touches
Check that the strip sits flush and doesn't rock. In wet areas like bathrooms, run a small bead of neutral-cure silicone along each edge to prevent moisture ingress — this is good practice and aligns with the moisture management intent of NZ Building Code clause E3. Wipe away any excess silicone with a damp cloth before it skins over.
Common Mistakes to Avoid
- Cutting too short — always measure twice, cut once. A gap at either end looks untidy and can be a trip hazard.
- Using the wrong fixing for the substrate — plastic plugs in concrete, appropriate screws for timber. Using the wrong fixings leads to strips working loose.
- Ignoring expansion gaps — if your laminate or timber floor has an expansion gap at the doorway (as required by most manufacturers), don't bridge it rigidly. Use a T-mould that allows the floor to move independently.
- Skipping the base track — some DIYers try to glue strips directly. Adhesive alone rarely holds long-term under foot traffic.
When to Call a Professional
Fitting a threshold strip is generally not restricted work under the NZ Building Code, and no building consent is required for this type of minor finishing work (though always confirm with your local council for your specific situation — MBIE Building Performance has useful guidance on Schedule 1 exemptions).
However, consider calling a qualified carpenter if:
- The subfloor is damaged, uneven, or needs structural repair before the strip can be fitted
- You're unsure about moisture issues beneath the floor — particularly relevant in older NZ homes
- The transition involves a wet area where waterproofing may be compromised
- You're fitting new flooring at the same time and want a professional finish throughout
You can find experienced local carpenters and flooring specialists on tradedirectory.co.nz.
Sources & Further Reading
- MBIE Building Performance – Building Code and consent guidance
- BRANZ – Flooring and subfloor guidance
- Bunnings – Threshold strips and flooring accessories
- Mitre 10 – Flooring transition strips
- Tenancy Services – Healthy Homes Standards
- Licensed Building Practitioners – Finding qualified tradespeople