Installing seam tape to EPDM Membrane

Residential Flat Roof Repair Edmonton, June 9 2015

Article: Residential Flat Roof Repair Edmonton, Alberta. EPDM Low Slope Roof Membrane.

Repair of an EPDM low slope roof on a residential home in Edmonton, Alberta. The low slope (flat) roof transitions to a pitched shingle roof. Penetrations and challenges include chimney, skylights, vents, drainage, ice damming, and insulating value on low slope. Additionally the transition between the low and steep roof systems posed challenges. Also a section on choosing the correct low slope membrane and roof assembly.
This customer had originally called us when Edmonton had set records for snow-fall in January of 2012. She had significant snow loads on her roof and the concern was that her roof may collapse. So we removed the snow from her roof and discovered significant ice damming challenges on the low slope portion.
We returned in 2013 and 2014 to do regular roof snow removal because every-time the snow built up on the roof the heat from inside her home would get to the underside of the low slope roof sheathing and cause ice damming. The ice dams would then get in between the laps of the existing roof membrane and result in leaks.
Mid 2014 she contacted us to quote on the replacement of the low slope roofing with hopes of solving the problem.
We quoted the various options for low slope roofing membranes, which included; Spray Foam (SPF), Tar and Gravel, SBS Torch-On, EPDM, TPO, PVC and Liquid Rubber.
Our standard quotations include pricing for the different options available for flat roof system membranes, a roof inspection report, a write-up on the pro's and con's of each type of system and our recommendations for your most suitable roof membrane choices.
Below is a sample flat roof quotation. The first link is a PDF download and the second is a Word Doc file download.
Our customer chose to replace her failing tar and gravel built up roof with an EPDM single ply membrane roof recovery (or retro-fit). This means that we removed the gravel and skinned the bitumen membrane off and then mechanically fastened a roof board and then fully adhered the EPDM. We also did some drain work and scupper work. Our customer did not opt for a complete removal, re-sloping with an engineered slope insulation system, or any additional R value added which could also have been done with simple rigid type insulation boards.
In early 2015 our customer had called with leaks to the low slope membrane - the ice dams were back. This is an important lesson in choosing the correct roof membrane, insulation, drainage, re-sloping and more. Had we been able to re-slope the roof and been able to add insulation value, the heat from the inside of the home would not escape and get to the underside of the roof membrane and cause ice damming. But, the customer requested the least expensive options and even though our reports (see link above for sample quotation and inspection report) explain in detail most considerations, this is the way it was requested to be done by the customer.
So this spring we returned to find the same ice damming causing issues with a now new membrane. We also found drainage issues which were expected - the roof was ponding because a re-slope was not in our scope. And there were some technical (debatable) installation tweaks that may or may not have been required. Nonetheless, we now had a new roof leaking the year after it was installed.
So of course we once again suggested the upgrade options to alleviate the issue but the customer would have nothing with that and requested we simply do the repairs and move on.
Below is an account from the crew of the type of repairs they did to try and mitigate any issues in the future (full well knowing that the prime aggravating factors are insulation value and sloping).
May 5, 2015: Crew Attends to Residential Flat Roof Repair.  We arrived on site at 9:58. We started the day with the toolbox meeting and safety documents. We then went up on roof to determine an installation plan. The scope of work we decided on and did is as follows.
Scope of Work # 1 The first step was to pull all EPDM down to flat roof from under the shingles at the bottom of the sloped roof. This reinstall was to ensure no water could be coming from the flat roof to steep pitch roof transition. We then had to remove all metal flashing from around the two skylights and chimney on the roof. Once we had all the EPDM pulled we started lifting shingles along the first few rows of the sloped roof and applied the EPDM bonding adhesive. This was done under the first couple layers of shingles and to the underside of the EPDM. We then installed the EPDM back under the shingles. Then next step was to apply a bead of water block on the edge of the EPDM under the shingles. Once that was complete we secured EPDM by screwing a piece of turn-bar down on the edge of the EPDM where the water block bead was applied.
Scope of Work # 2 The crew arrived on site at 1 pm and started working on the cricket behind the chimney.  He started by cutting a piece of EPDM 7'x3'. He then had to take the Epdm bonding adhesive and apply in the same manner as the work in scope # 1 by applying the adhesive under the shingles as well as the under side of the Epdm. Once the 7'x3' piece was installed he started working on the corners. Using quick prime and seam tape he seamed in the corners of the Epdm around the chimney.
WORK LEFT TO DO: -patch corners -more turn bar and water block -install and or replace shingles Roughly 6 hours of work left to complete.
MATERIALS USED: -7'x3' piece of EPDM -EPDM bonding adhesive 1/3 of a pail -screws -30 ' of termination bar - 2 tubes of water block -tube of caulking for skylights -half a tube of lap sealer for temporary seals -6 feet of seam tape - quick prime 1/8th of a pail.
Residential Flat Roof Repair Edmonton. Pulling EPDM out from under shingles.
Residential Flat Roof Repair Edmonton. Pulling EPDM out from under shingles.
Peeling back Epdm membrane from skylight curbs.
Peeling back Epdm membrane from skylight curbs.
Taking flashing off chimney
Taking flashing off chimney.
Applied EPDM Adhesive
Applied EPDM Adhesive.
Rolling EPDM back under shingles after adhesive was applied.
Rolling EPDM back under shingles after adhesive was applied.
Installed Piece of Termination bar on tup edge of EPDM (under shingles)
Installed Piece of Termination bar on top edge of EPDM (under shingles).
joining two seams of EPDM, with quick prime and seam tape
Joining two seams of EPDM, with quick prime and seam tape.
May 8, 2015: Residential Flat Roof Repair Crew Attends.
We started at 7:30 AM with a daily tool box meeting. We then got up on the roof and started shoveling snow away from work area so we could complete today's scope of work.
Scope #1. Scope one consisted of applying corner patches to the rear corners of the chimney. The next step was to apply tape primer to the EPDM surface on the corner of the chimney. We then cut 6"×6" squares of 6" covers strip  to use at the corner patch.  We applied  this piece on top of the tape primer and let it sit to cure.
Scope #2. Install termination bar for the EPDM on the front of the skylights. For this we measured and cut a piece of turn bar to fit the front side of the sky light. We then screwed (mechanically fastened) the termination bar.
Scope #3. We had to take the bottom two layers of shingles off and replace with new ones. For this we had to carefully lift the bottom rows of shingles and pry out the nails so the shingles would slide out. We then took the new shingles and installed them. This consisted of laying down the first layer and nailing in place. The next step was to put on the second row of shingles which slid under the old existing one and nailed in place half way down the first shingle we layer down. Job is complete.
Completion photo #1 of where shingles at steep pitch meet low slope EPDM membrane.
Completion photo #1 of where shingles at steep pitch meet low slope EPDM membrane.
completion photo #2
Completion photo #2.
Materials Used:
-2 bundles of shingles
-roofing nails
-8'of turn bar
-2' of cover strip
- tape primer

< End of report >

Click here to visit our local roof repair website and order a quotation for flat roof repair in Edmonton or area or contact us per below.

Call our 24 Hour Emergency Roof Repair at 1.780.424.7663. Mail to: 3428 99 Street NW Edmonton, Alberta T6E-5X5.
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