Six ways to build an EPDM roof.

Layers, from the deck up

1. Concrete deckClean, dry, sound; voids wider than 5 mm are filled first.
2. SA-19 PrimerPrepares the deck for the self-adhesive vapour control layer.
3. V-Gard vapour control layerSelf-adhesive aluminium-faced sheet, laid cold.
4. I.S.O. Twin Pack insulation adhesiveBonds the boards to the V-Gard.
5. PIR insulation boardsThickness chosen for the heat loss the roof must meet.
6. ISOGARD HD cover boardWhere the project calls for it: a firm, smooth surface for the membrane.
7. Bonding Adhesive BA-2012Contact adhesive, rolled onto both surfaces.
8. RubberGard EPDM, 1.1 or 1.5 mmRelaxed for about 30 minutes, then pressed into the adhesive.

Rules we work to

• Built for wind loads up to 4 000 Pa.
• Contact adhesive goes on both surfaces and is left until it passes the touch test.
• No adhesive in the seam zone. Seams: at least 100 mm overlap with 76 mm QuickSeam Splice Tape.
• Bonding Adhesive BA-2012 is applied between 5 °C and 35 °C.
• Upstands: membrane bonded at least 150 mm up the wall.

For cold-weather work there is a self-adhesive version, RubberGard SA, which goes down at temperatures as low as −7 °C. It is used in fully adhered systems only.

Details: Lap seam · Upstand · Roof edge

Layers, from the deck up

1. Profiled steel deck, at least 0.75 mm
2. V-Gard vapour control layerWhere the building needs one.
3. PIR insulation boardsEach board held with insulation plates and fasteners.
4. RMA fastening strips254 mm strip with two 76 mm tapes, fixed in lines.
5. RubberGard EPDMLaid over the strips and bonded to the tape.

Rules we work to

• The number of fastener lines and the spacing come from a wind load calculation for your building. We do not guess them.
• Seams: at least 100 mm overlap with 76 mm Splice Tape, the same as on bonded roofs.
• At every upstand and edge the membrane is also fixed at the base with a perimeter strip, fixings no more than 300 mm apart.

Two other ways of fixing exist. In the seam: a metal batten is fixed inside the lap, which then needs at least 200 mm overlap and the wide 152 mm tape. Over the sheet: the batten goes on top and is covered with a Batten Cover Strip that runs at least 75 mm past each end.

Details: Fixing in the seam · Upstand · Lap seam

Layers, from the deck up

1. Concrete deck
2. Vapour control layerWhere the building needs one.
3. Insulation boards
4. RubberGard EPDM, laid loose
5. Protection geotextile, at least 200 g/m²Turned up at the upstands.
6. Ballast, at least 50 kg/m²More where the wind calculation asks for it.

Rules we work to

• Only for roofs with a slope of 10% or less.
• Ballast at least 50 kg/m², more at corners and edges if the wind calculation says so.
• The geotextile protects the membrane from the stones.
• Walkway pads are kept at least 3 m from the roof edge.

The same build can carry concrete paving slabs or pedestal-mounted tiles instead of gravel, for a terrace.

Details: Upstand · Drain

Layers, from the deck up

1. Concrete deck
2. RubberGard EPDMThe waterproofing sits under the insulation.
3. XPS insulation boardsClosed-cell boards that can take water.
4. Filter geotextile
5. Ballast

Rules we work to

• Slope 10% or less, the same as other ballasted builds.
• Ballast holds both the boards and the membrane in place.

Details: Drain · Upstand

Layers, from the deck up

1. Concrete deck
2. Vapour control layer
3. Insulation boards
4. RubberGard EPDM 1.5 mmRoot resistant to EN 13948.
5. LDPE sheet over the seams, at least 0.4 mmOr the seam edges sealed with Pourable Sealer.
6. Drainage layerBy the green roof supplier.
7. Growing medium and plantsWith a gravel strip at the edges.

Rules we work to

• Only 1.5 mm membrane. Not the 1.1 mm and not the self-adhesive SA.
• Seams protected with LDPE sheet at least 0.4 mm thick, lapped at least 1 m, or sealed with Pourable Sealer along the edge.
• A strip at least 500 mm wide along edges and upstands stays free of plants, filled with gravel.

Details: Upstand · Drain

Layers, from the deck up

1. Profiled steel deck
2. SA-19 Primer
3. V-Gard vapour control layer
4. PIR insulation boards
5. ISOGARD HD cover board, 12.7 mm
6. RubberGard EPDM 1.5 mm, with walkway padsPads in the service paths.

Rules we work to

• Membrane 1.5 mm, never 1.1 mm, under solar panels.
• ISOGARD HD cover board spreads the load of frames and feet.
• Walkway pads wherever people will walk to service the panels.

Details: Walkway pads · Pipe and cable outlets