Best Cat Door for Sliding Glass Doors — The Permanent, In-Glass Solution (US Guide)
Search "cat door for sliding glass door" in the US and you'll mostly find one product type: the spring-loaded insert panel that sits in your slider track. It works — but it stops your slider closing against its own frame, leaves your main lock unusable without extra hardware, and looks like the temporary fix it is. There's a permanent alternative American cat owners rarely hear about: a round cat door fitted into the glass itself, the standard method in New Zealand and Australia for decades. Here's how it works, which Catwalk® models suit US sliders, and how to get it installed by any local glass company.
- An in-glass cat door keeps your slider rolling, closing and locking exactly as before; the flap lives in the glass, not the track.
- US slider glass is tempered and can't be cut, so a glass shop fits a replacement panel with the round opening pre-cut: routine work, and fully reversible for renters.
- Catwalk® doors are 100% mechanical: no batteries, no electronics, no adapters: nothing that varies by country, and spare parts are available for every model.
In-Glass Cat Door vs Track Insert Panel
| In-Glass Cat Door (Catwalk®) | Track Insert Panel | |
|---|---|---|
| Slider operation | Unchanged — rolls, closes, locks normally | Slider closes against the insert, not the frame |
| Home security | Original lock works; flap has its own 4-way lock | Main lock typically unusable without add-on hardware |
| Insulation | One sealed flap in the glass | Two extra full-height seams in the doorway |
| Appearance | Factory-fitted look, near-invisible in clear | Visible aluminum panel in the track |
| Install | Local glass company fits a replacement panel | DIY, minutes |
| Renters | Reversible — original panel swaps back at move-out | Removable |
The insert panel's one genuine advantage is tool-free installation. If you own your slider for the long term, the in-glass door wins everything else.
How It's Installed in a US Slider
US sliding door glass is tempered safety glass, which can't be drilled after manufacture, so nobody cuts your existing panel. Instead, any local glass company (search "glass replacement" or "glass shop") does this:
- Measures your slider panel and confirms the glass spec: single pane or insulated (double pane) unit.
- Orders a replacement panel with the round cat door opening cut before tempering. The finished panel is full-strength safety glass with the hole already in it.
- Swaps the panels in a short visit and fits the Catwalk® door; the unit clamps through the opening and seals. Your original panel comes out intact; renters keep it and swap it back at move-out.
- Round cut-out size: 245mm (9.65″) or 267mm (10.5″) depending on model
- Your glass type: single pane or insulated (double pane) unit
- The fitting instructions from the box — glass range and clamping detail
Any glass replacement company can do this — no specialist required.
The round opening is the key to easy quotes: one core-cut, no corner stress, a shape glass shops process routinely, the same reason glaziers prefer round cut-out pet doors everywhere Pet-Tek sells. The full technical background on tempered glass and insulated units is in pet doors in toughened & double glazed glass (toughened = tempered). One more detail matters in a slider, where the outside face takes direct rain: the draft angles inside the Catwalk® body are shaped so any water driven into the frame drains straight back out rather than sitting inside it. Doors that pool water grow mould and corrode their fixings; ours are moulded to leave water nowhere to settle.
Which Catwalk® Model for a US Slider?
| Model | Best For | Flap Opening | Glass Range | Round Cut-Out |
|---|---|---|---|---|
| G-CDC (clear) / G-CDW (white) | Most cats, single-pane glass | 193×165mm (7.6×6.5") | 3–10mm (1/8–3/8") | 245mm (9.65") |
| G-MCDW multi-magnetic | Keeping strays & raccoon-curious visitors out — battery-free selective entry | 170×155mm (6.7×6.1") | 3–26mm (1/8–1") | 245mm (9.65") |
| G-SDDSLC / G-SDDSLW maxi slim | Large cats, single-pane | 203×187mm (8×7.4") | 3–21mm (1/8–13/16") | 267mm (10.5") |
| G-SDDC / G-SDDW / G-SDDB maxi dual glaze | Large cats & insulated (double-pane) units | 203×187mm (8×7.4") | 3–28mm (1/8–1.1") | 267mm (10.5") |
Most US sliding doors have insulated (double-pane) tempered glass, so the maxi dual glaze models (G-SDDC/W/B) are the pick: the 8×7.4" flap suits everything up to Maine Coon size, and the 28mm range covers standard insulated units. Neighborhood strays a problem? The G-MCDW's magnetic selective entry runs on zero electronics — your cat's collar magnet is the key. Single-pane slider (older homes, mild climates): the original G-CDC in clear disappears into the glass. Draught performance carries over too: the flap-to-body gap is machined to next to zero tolerance and finished with a full brush seal, so the sealed unit you paid for keeps doing its job.
Ordering from the US
- Shipping: Pet-Tek International ships from Auckland, New Zealand to the US and 20+ countries — contact us for a shipping quote and current delivery times.
- Nothing to adapt: the doors are fully mechanical: no batteries, no power, no plugs, no frequency or voltage questions. What works in Auckland works identically in Austin.
- Order the door first, then book the glass shop: they need the cut-out size (9.65" or 10.5") and the glass range from the fitting instructions in the box.
- Sizing: measure your cat per the measuring guide — width at the widest point plus 1", and when in doubt go up a size.
- Parts for life: replacement flaps and seals ship worldwide for every model, including doors made 20+ years ago.
Frequently Asked Questions
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