EPDM Flashing and Detailing

Firstly, the items you will need have differing purposes:

6 inch, 9 inch & 18 inch Quickseam Formflash, is an uncured laminated EPDM, specifically for 3D moulding - for purposes such as corners, pipes & other awkward details.

5inch Flashing Tape & 6 inch Batten Tape, is a semi-cured laminated EPDM, specifically for 2D bonding for joins onto batten bars, felt & fibreglass joins, and other EPDM joins.

3 inch Seam Tape is specifically designed for splicing together two pieces of EPDM membrane.

For all of the above flashings, you will need: A Quickscrub Pad & Handle (sometimes a small disposable paint brush), Quickprimer Plus, & a Silicon Rubber Roller/Penny Roller. 

There are specific descriptions for completing the above types of flashing within the guides. Some general rules are:

The area which your flashing will bond to must be clean, free of debris & dry. Porous or wet surfaces such as tiles & brickwork, will need more attention here for better adhesion.

Any area you will be bonding your flashing to, must have Quickprimer Plus applied to it, using your Quickscrub handle & pad. Offer some primer to the pad, then rub into position on the surface, keying the area gently - don't leave any pooling of liquid.

The primer must be touch-dry & tacky before bonding.

When applying your flashing into position, asides for the 3 inch seam tape, the side which has the tape on - is the side which will adhere to your primed area.

Before you bond your flashing, it is worth offering in place with the tape on, to ensure correct position & that there is sufficient primer 10mm clearance on all edges.

You will want to start at one edge, or side, & partly peel some of the taped side back. Then begin to smooth the flashing into place, taking care not to create air pockets as you go.

Once your flashing has been bonded to the primer, it will not come back up, so take considerable care when applying - even our experience team occasional makes small errors when flashing (can always be corrected).

Work in with your Silicon Rubber Roller on flat surfaces, & with your Penny Roller into corners & crevices.

Providing your flashing has been applied correctly, this area is sealed. 

As an extra precaution though, Firestone Elevate Lap Sealant can be applied to all your flashing edges. Cut an appropriately slanted nozzle, & apply a neat continuous bead all along the edge.

You should take care not to apply too proud a bead, especially when water run-off direction will run over it, potentially causing sitting water.

As an example, here is where flashing will be applied to where your roof edge corner, terminates between a wall & roof edge.

Step 1: Your EPDM is bonded to your deck, vertical wall & chase.

Step 2: Cut your 6 or 9 inch Quickseam Flashing (whichever is more applicable) to size, positioned at the edge of your vertical wall run - lapping 75mm onto the EPDM vertical, 75mm onto the continued brickwork, & 75mm down onto the decking.

Apply your Quickprimer Plus to this area, plus an extra 10mm, as well as your wall chase if applicable.

Step 3: Once touch dry, apply your flashing, as described previously. Start at the top, leaving 10-15mm to go into your chase if needed, working down the wall & 75mm onto your decking.

Then work the excess flashing into the corner past the decking.

Work in with your Silicon Rubber Roller & Penny Roller.

Step 4: Apply Firestone Elevate Lap sealant to your edges, then, if applicable, install your wall trim & seal your chase.

Note: When it comes to your flashing in this case: Flash your corner before installing kerbs to the roofing edge, or after installing gutter trims to the roofing edge.