Flashing And Sealing Icf Openings

TIMS

Hi all, great site and great advice.
I'm designing a Durisol ICF home and need to specify methods for flashing and sealing window and door openings into stucco, and also sealing or flashing wood beam lintels that will be exposed on the exterior and interior of the home. The client wants an adobe look to the home so the openings will curve into the windows and doors. Thanks.

Chris Johnson

Your window bucks are going to be made out of one of 4 different products, PT wood, Vinyl of some form, Galvanized Metal or Concrete.

As for flashing, follow the same procedures as you would with conventional construction...nothing changes.

An air barrier is not required on ICF, however, most building departments still require it when conventional stucco is used. That being said it will work the same as conventional framing.

If you windows are being recessed into the middle of the ICF wall you will need to use min. 12" wide flashing and possible double it up (width wise) to get from the window out to the face of wall and get enough coverage on the wall.

Vertical seams in the flashing require a 2" lap, Horizontal require 6"

As for creating the curved frames you may want to consider 'oversizing' the rough opening, complete the pour, install the window in some 2x framing material and filling the difference and creating the curve with either architectural moldings or make your own molding to match what they want.

For the wood beams, check with the local inspector, if the beam is set after the pour into cured concrete and exceeds 6" above grade you can place it against the concrete. If that is an issue, wrap the in contact piece with the window flashing and trim off the exposed excess. This is the same method I use when casting concrete around wood that is installed prior to the pour.

Another though that I have done is create a standard concrete lintle above window and door openings, as the finishes are being applied use thinner beams (say 2x material) and fasten directly to the ICF it becomes a faux beam and no one knows the difference.

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Chris

TIMS

Great advice Chris! I have included a detail drawing of what I'm proposing for the lintel and curved opening. Is the flashing metal or an Ice and Weather Shield type? Also they want to use antique beams that will be the full wall thickness. My concern is futur leakage at the contact point of concrete to wood. possibly a keyway cut into the top and sides of the lintel or foam backer rod attached to the lintel, any ideas?

TIM

Attached Files

WINDOW DET..pdf (21.9 KB, 197 views)

Chris Johnson

The flashing is ICE & WATER shield, I suppose y6ou could use bent metal, more money though and will need to be soldiered at the seams.

Your wood lintel detail can leak, very difficult to seal. sealing between the foam and the wood may not prevent a leak. I can't see a big enough keyway in the wood to prevent a possible leak, or if it was big enough there will be no structutral integraty left in the beam.

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Chris