IKO enertherm ALU TAP: scheduling tapered insulation for a large roof

Outline the catchment for each outlet on the roof plan. Check the actual outlet position and the deck level beside it on site. Moving an outlet from its drawn position changes the length of at least one drainage path. Resolve that difference with the designer before issuing boards for installation.

IKO enertherm ALU TAP boards have a PIR core, aluminium facings, square edges and a 1,200 × 1,200 mm format. IKO gives a declared thermal conductivity of 0.022 W/(m·K), reaction to fire class E and a compressive strength of at least 175 kPa at 10% deformation. Specify the gradient and both edge thicknesses when ordering. The range available can vary by market.

At a 1.25% gradient, the rise over one board is 15 mm. Four boards span 4.80 m and give a total rise of 60 mm. On a level base, a run starting at 30 mm could use boards of 30–45, 45–60, 60–75 and 75–90 mm in sequence. The final thickness of one board matches the starting thickness of the next.

The surface elevation at the outlet also depends on the layers beneath the taper. Include any specified flat insulation in the section. Thermal calculations need to account for the varying thickness of the assembly. Measuring the rise alone cannot establish the roof U-value.

At a ridge, mark which outlet receives the water on each side. At a valley, also check the fall along its centreline. Identify cut pieces separately on the layout and the packaging. A similar edge thickness alone is insufficient to justify exchanging tapered pieces between drainage areas.

Check the start and end elevations of the row against the same datum. Inspect board joints and measure any apparent steps. If the end elevations match the plan but there is a hollow between them, find its cause before waterproofing.

On the delivery list, include the drainage area, row, thickness range and piece count. Agree pallet locations with the person responsible for the roof’s load capacity. Once a pack is opened, keep the remaining pieces identified, especially if installation stops halfway along a row.

Keep the marked-up layout with the final outlet positions and measured elevations at drainage boundaries. A photograph labelled with the row reference locates a tapered board after it is covered. If a plant base is added later, the maintenance team can check whether it crosses a recorded drainage path.