When ordering a Flush roof lantern and constructing your opening there are three key considerations:
1. That the sizes quoted on this website refer to your internal timber up-stand sizes.
2. That the internal size of your up stand accounts for the pitch of your structure (see drawing bellow)
3. That your timber up-stand should be between 80-85mm thick.
When ordering a Flush roof lantern the key to a successful order is understanding that the sizes advertised on the website relate to the internal size of your timber up stand. Please follow these simple steps:
1. Measuring the internal sizes: Place your measuring tape inside your timber kerb at the very top of the up stand (as shown in the picture bellow)
2. From here extend your tape to the opposing side of the kerb making sure again to measure to the very top of the up stand (as shown in the picture bellow)
3. Repeat this process again to establish the width and you will have measured your roof lantern. The size you have measured should then relate to the size roof lantern you have ordered
Your timber up-stand should be 80mm thick as this will provide you with some slack when installing your roof lantern. Please refer to the bellow drawing showing the 80mm thickness.
The actual kerb of the lantern that sits on your 80mm timber up stand is 86mm as shown in the drawing above. From here there is then a U channel that projects into your room and an external cap that extends outside of the kerb. These two features have been cleverly designed to create a stop bead for your plaster board internally and a rain drip externally.
Internal Plaster board receive.
The internal U-channel circled bellow is a 15mm stop bead designed to receive your plaster board and allow a skim finish. This will then allows you to create an infinity finish.
On the outside of the 86mm kerb there is a 10mm drip that extends over the edge of the kerb to create a weather drip