McGrath Ultra Secua & Triple Lock Kits – What Works, What Doesn’t & Installation Advice

The McGrath Ultra Secua range is a purpose-designed smart lock for hinged security screen doors. It is robust, IP66 rated, and engineered specifically for Australian conditions and common screen door profiles.

Where confusion can arise is when the Ultra Secua is paired with an existing triple (3-point) locking system. McGrath correctly advises that the Ultra Secua is compatible with most triple kits, however triple kits themselves vary significantly between brands and generations.

This article explains what works, what doesn’t, and why some installations benefit greatly from professional fitting.

Door compatibility (important before you start)

The McGrath Ultra Secua is designed only for:

• Hinged security screen doors

It is not compatible with:

• Sliding screen doors
• Sliding glass doors
• Hinged glass doors

Sliding and glass doors use completely different locking geometries and require alternative smart lock solutions.

Understanding triple lock kits

A triple (3-point) locking system secures a hinged screen door at:

• the centre lock
• a top locking point
• a bottom locking point

These additional locking points are driven by the main lock using either solid rods or flexible cables. This distinction is critical.

Ultra Secua compatibility with triple kits

The Ultra Secua uses a rigid, mechanically driven actuation system. This provides excellent reliability and weather resistance, but relies on direct push-pull movement to operate additional locking points.

Cable-based triple kits

Triple kits that use flexible cables are generally not compatible with the Ultra Secua. Cable systems rely on tension rather than positive mechanical engagement, which can result in inconsistent locking and binding.

Rod-based triple kits

Triple kits that use solid rods are generally compatible when installed and adjusted correctly. Rod systems provide the linear movement the Ultra Secua is designed to drive.

Brand-specific installation notes

Austral triple kits

• Cable-based Austral kits – not compatible
• Rod-based Austral kits – compatible when installed correctly

Whitco Tasman MKII triple kit

The Whitco Tasman MKII triple kit is a known compatible option, however it is not a simple bolt-on retrofit. In many cases the top bolt must be reversed, changing its position and requiring strike relocation and door modification.

Lockwood triple lock kits

With many Lockwood triple kits, the entire assembly must be removed and reinstalled as one complete unit in reverse, including rods, bolts and plastic connection components.

This results in the top latch relocating to the bottom cut-out and the bottom latch relocating to the top cut-out. Door removal, drilling, cutting and strike relocation are commonly required.

A common and practical alternative

In many homes, the simplest and most reliable solution is to remove the triple lock kit entirely and install the Ultra Secua as a single-point lock.

• Simpler installation
• Fewer moving parts
• Excellent real-world security for most residential applications

Helpful installation videos

• Installing Ultra Secua Digital Lock with Austral Triple Lock Rod System
• Adding Ultra Secua Digital Lock to a Whitco Triple Lock
• Adding Ultra Secua Digital Lock to a Lockwood Triple Lock

Frequently Asked Questions

Is the Ultra Secua suitable for sliding or glass doors?

No. The McGrath Ultra Secua is designed exclusively for hinged security screen doors. It is not suitable for sliding doors or glass door applications, which use completely different locking systems.

Can I keep my existing triple lock?

In some cases, yes. If your triple lock kit uses solid rods, it is often compatible when installed and adjusted correctly.

If your triple lock kit uses flexible cables, it will not be suitable for use with the Ultra Secua and will need to be removed or replaced.

Does installing the Ultra Secua with a triple kit require door modification?

In many cases, yes. Retrofitting the Ultra Secua to an existing triple lock system often requires door removal, drilling, cutting, and strike relocation to ensure correct alignment and reliable operation.

What’s the easiest way to avoid installation issues?

The simplest option is either:

• using a confirmed rod-based triple lock kit with professional installation, or
• removing the triple lock kit entirely and installing the Ultra Secua as a single-point lock.

Both approaches significantly reduce complexity and improve long-term reliability.