Installing an In-Betweenie Window (1): Sill Pan Flashing

May 30, 2016

 

Flashing an In-Betweenie window is a lot like flashing an Innie or an Outie, only it is somewhere in between

 

This is the first part of a three part series on installing in-betweenie windows; see part 2 for jamb and head flashing and part 3 for putting the window in the hole

Official Transcript:

Ben cuts back the high performance weather barrier and chooses the martini glass shape. Not because he is a fan of classic cocktails, but because he is going to use the WRB for jamb flashing in the next video.

  • He measures in from the outside to snap a line indicating the inside of the window.
  • He slices the outer corner of the WRB so that he can tuck the peel and stick flashing membrane under. Which he then cuts — about eight inches longer than the opening. 

Then he gets ready to peel and stick the peel and stick.

"The back side of this membrane has three release strips, so we start by using the small one to use as a positioning strip."

The second strip covers most of the window sill and the last one will wrap around the corners.   

"Before you pull anything off, get your membrane in position. I like to see about four inches turned up on either end. 

I only pull of as much as I need to apply, because as soon as this stuff sticks, it sticks."

"So I use a little squeegee to get the corners nice ..."

These tapes are pressure-sensitive and they must be tooled when applied.

  • The corners are stuck to the line that he snapped a few frames back.
  • Tighten the corner with a squeegee, and then pull off rest of the backing paper and chuck it on the floor.
  • He rolls first strip with a J-roller.
  • Removing the middle strip of backing is more touchy—

Ben: You can see right here, you want to get yourself pulled back so that you are beyond that corner. Because if you are like this, and you go to pull the release paper off, oftentimes, it'll kink and tear right there—and then you are trying to chase a little edge to get it peeled back ... it becomes a nightmare."

"The sun's on us so this stuff is getting super-duper sticky. 

 Just kind of let it relax into the corner—"

Zen and the art of window flashing

"—try not to force it, 'cause when it’s stuck, it’s stuck." 

"There are no second chances."

Squeegee the corner, pull out the rest of the release paper, and break out the roller buggy.

 

The final strip of membrane will bend around the corners.

  • Peel off the release paper being careful not to tear it in the process.
  • Bend the membrane around the corner, but don’t get carried away: Ben points out that whenever you stretch a material you thin it, and this is not a place where thinner is better. Just about like that is perfect.
  • Break out the roller buggy again. Vroom, vroom.

 

Now, Ben is ready to flash the jambs and head before setting the window in the middle of this thick, thick wall. 
 

—Ben Bogie owns Built to Last Design & Build, LLC, in New Milford, CT

 

Banjo Hop by Audionautix is licensed under a Creative Commons Attribution license (https://creativecommons.org/licenses/by/4.0/)
Artist: http://audionautix.com/


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