How To Flash Around Openings In ICF Walls With Synthetic Stucco (EIFS) Exterior Finish
My question is this: For ICF construction using wood bucks for window and door openings, what are the best techniques to flash around window and door openings, assuming that EIFS or Stucco will be the exterior finish, to prevent or minimize the potential for leakage around openings, especially in areas subject to high winds, driving rain, etc?
I have looked at the design details for many different ICF’s and can’t say that I have seen a detail for flashing around openings that looks like it will do the job of protecting against moisture intrusion. One company shows cutting an angled kerf in the foam over the top of openings. This looks like it might work if a metal flashing is used that can be bent to fit in the kerf. Window and door manufacturers have done a good job of providing details on flashing their products during installation. Most of the details I have seen, however, are specifically designed for stick-built construction.
What should be done for ICF projects with EIFS and Stucco if the “peel n stick” type flashing products are the preferred choice. What techniques are used to insure adherance of the EIFS or Stucco to these flashing products? Stucco lath, other? How far above the openings should the flashing be installed? What if the walls are parapet walls and there are no roof overhangs to protect the upper walls over openings?
Thanks
Replies
The EIFS manufacturer should have a PDF available for details like that.
Attached is one from Dryvit - I found it for my BIL when he was looking at EIFS.
ICF:EIFS and Direct Applied Coatings
Kiowa,
You're asking good questions that indicate an appreciation for the detatils associated with direct applied coatings over ICF. In short, it's not easy.
First off, the previous reply included an attached document from Dryvit (which does have details for ICF systems). However, the attachement is for a residential application of typical EIFS and not for ICF. The attachment you want is DS193 (attached). Have a look at detail DS193 0.0.08, Wood Buck Window.
Dryvit also has a Liquid Trowel Applied membrane equivalent in testing standards to peel and stick membranes. The beauty of the product is that it is compatible with all components that your are dealing with: Wood, Expanded Polystyrene, Concrete and even the Dryvit Basecoats. This product is called "Aquaflash" (also attached as file DS 494). Aquaflash can be applied to the rough openings prior to the windowmechanical unit being installed.
The coatings used directly over the ICF are not compatible with wood. Therefore, you will notice an EPS profile being used to bridge the exposed section of the wood buck. This allows the coatings to meet with the window unit for continuity. There are many more details where integration detailing is crucial. Make sure you go through all the scenarios with your chosen applicator. A very important detail is roof flashing where the roof intersects a wall elevation. The same EPS profile technique should be employed to acheive a "positive overlapping of materials". In other words, the coatings need to overlap flashing (flashing should not be caulked to the face of coatings). I have used a 6" strip of AquaFlash to bridge onto the flashing from the ICF foam to make it waterproof before applying the EPS profile. In facct I use the AquaFlash at all integrations to waterproof before going with coatings or EPS profiles.
Good Luck!
Thanks
Appreciate the details.