1. Check the dimensions

Before installing, check the total height of the components to ensure the correct finished level is achieved. Allowance must be made for the thickness of any membranes used and, where applicable, roof insulation.

2. Fit spigot and check outlets

Screw spigot, where required, into the body, using a suitable sealant to create a watertight joint. Position the body in the roof deck and ensure the outlet is accessible.

3. Install body

Install body so that the flange is at or just below roof deck level. If the body is not cast in it should be secured to the deck. Use a wide flanged body for timber decks. The flange can be drilled for fixings or use an underdeck clamp (33.9610 or 33.9620). If the deck is recessed for the flange consider the need to reinforce the cut timber edge.

Note: Membrane flange level is determined by the roof build-up

4. Dress membrane and fit clamp

Dress the membrane over the flange over the edge of the body sump in accordance with the manufacturer’s instructions, ensuring that the membrane does not restrict the outlet. Ensure that the flange is at or below the level of the membrane.

Bolt the membrane clamping collar to the body using the supplied fittings. Thin membranes may require the screw length to be reduced.

5. Install insulation

Install any additional roofing materials and build-up (e.g. insulation) around the roof outlets.

6. Fit dome and apply finish

Fit the dome or grating using height adjustment where applicable to ensure grating is flush with the roof finish.