EPDM Pipe Sealing

A step-by-step guide to sealing your EPDM around pipe extrusions from your flat roof.

Step 1: Measure the diameter of your pipe. Cut the opening on the top of your Pipe Boot to match.

Step 2: Slide the Pipe Boot over the pipe, flush to the deck. Using your crayon/chalk, mark this perimeter, plus an extra 10mm. Then gently fold the base up so you can apply primer.

Step 3: Using your Quickscrub pad & handle, apply an even coverage of Quickprimer Plus to the area within your chalked circle, no pooling of liquid.

Step 4: Once touch-dry or tacky, fold back down the base of the Pipe Boot, locate the join in your paper on the underside. Slowly remove this at a shallow angle, smoothing down as you go.

Work in with your Silicon Rubber Roller.

Step 5: Gently peel down the top of your Pipe Boot. Apply a continuous bead of Bond & Seal around the pipe and carefully fold back up the top of your Pipe Boot, compressing the sealant. Remove and neatly smooth over excess sealant.

Step 6: Using your jubilee clip, secure the top of the Pipe Boot and tighten, snipping away excess clip.

This may further bulge out some sealant, wipe excess or neatly point.

Further steps for awkward pipes, vents, or soil pipes with no open end etc:

There will be some occasions when some more bespoke flashing will need to be installed to waterproof around pipe extrusions.

For example, the top of the pipe you wanted to slide your pipe boot over, may be extremely wide, narrowing at the base. To remedy this, you may need to cut a line down your pipe boot to β€˜wrap-around’ the base of the pipe, then add extra flashing, rather than slide down.

Alternatively, a soil pipe may exit a wall, just above your roof decking and run up vertically.

In these occasions, there are some principles below, which you can employ to help make sure you have a water-proof seal. You can always contact us for more help if needed:

Tip 1: As a general rule, always allow for a flashing overlap of 75mm onto your EPDM, the surface you're bonding to, & over adjoining pieces of flashing. This will allow sufficient bonding surface as a starter.

Tip 2: When you are overlapping separate pieces of flashing vertically, start at the bottom & work upwards with each new piece.

This way, each piece of flashing is lapped over correctly in terms of vertical water-flow.

Tip 3: Ensure every area is clean & dry! This will aid EPDM & flashing bonding.

Tip 4: If your flashing needs to bridge from a pipe to a wall, ensure its supported first by some timber boxing, and can ideally dress into a wall chase.

Don’t screw into the pipe! Secondly, where possible add a gradient to your boxing to encourage water flow away from exposed areas and to your gutter edge.

Tip 5: As an extra precaution, apply Firestone Lap Sealant to all exposed edges of you flashing.