The TFD is designed to be installed onto an existing upstand or curb, or where installers prefer to fabricate their own flashing system.

It is not supplied with flashings and is intended for situations where roof detailing is already in place or being custom-built.

TFD is typically chosen when:

- An existing skylight needs to be replaced without disturbing roof flashings
- A custom flashing or curb detail is required
- The installer prefers to fabricate flashings on site
- The project involves refurbishment or staged works

It provides flexibility without requiring a full skylight replacement.

In many cases, yes — subject to dimensional compatibility.

TFD units are commonly used as replacement tops where the existing upstand is structurally sound. Final suitability should be confirmed by measuring the upstand and confirming compatibility before ordering.

No. The TFD is supplied without flashings.

It is intended for use on existing upstands or where the installer is fabricating their own flashing system. If a complete skylight assembly with flashings is required, a Traditional Skylight should be selected instead.

TFD is the right choice when:

- Replacing an existing skylight top
- Using a pre-existing or custom-fabricated upstand
- Minimising roof disturbance is important
- A simple, low-profile daylighting solution is required
- Installation responsibility sits with the builder or installer