Hello again Low-Sloper!
Welcome back to another segment in the Joe Knows series! In this session, I will instruct you and your team through the process of flashing the outside corner of a parapet wall (Construction Detail CT-10). This CertainTeed-approved installation detail will be a valuable tool to add to your belt.
Let’s Grab Our Hard Hats and Get to Work!
The outside corner of a parapet wall is a curb at the reverse angle of the inside corner. When installing this detail, I want you to think of base flashing similar to wrapping a present. You will be creating cuts and folding our Flintlastic® SA NailBase – your “wrapping paper” – to take the shape of the corners and ensuring a watertight seal.
In addition, similar to my previous session, how to base flash a parapet wall (Construction Detail CT-06), you can’t move forward with the process without installing the cant strip.
For successful installation, please follow the steps below, and then watch my quick demonstration video to see it in action.
1. First, when putting your field membranes in place, make relief cuts in all roofing layers to allow the membrane to make the corner’s shape.
2. Starting with your anchor flashing or backer sheet in this video, Flintlastic SA NailBase, make relief cuts to accommodate the top edge downturn and the corner.
3. For the downturn, cut on an angle from the wall out. For the corner, make a straight cut – parallel to the wall out. The sheet will now drop into place.
4. At the bottom of the corner, make a straight cut from the top of the cant and from the bottom of the cant on an angle. Mirror and repeat these steps on the adjacent wall.
5. When applying your cap flashing, no cut is necessary on the top of the corner, but similar cuts are required at the bottom corner. Mirror those cuts on the adjacent wall.
7. And then lastly, to ensure the bottom of the corner is watertight, attach two patches where the corner cuts were made. CertainTeed does not dictate the shape of the corner patches, so get creative!
Awesome work, you have learned another installation detail. If you have any questions, you can submit via this form or leave a comment below.
In the meantime, keep an eye out for my next blog and video post detailing the installation method for base flashing the inside corner of a parapet wall (Construction Detail CT-09).
Oh, and if you missed it, check out my previous installation articles:
Find all our Construction Details here: https://www.certainteed.com/pro-center/roofing—roof-systems-specifications/Learn more about CertainTeed Commercial Roofing: https://www.certainteed.com/commercial-roofing/