Sealant Application and Joint Design
A rash of water intrusion problems on residential EIFS applications in Wilmington, NC received national attention in the mid 1990’s. The NAHB had determined that most of the water intrusion problems are due to either:
- the absence of sealant or
- improperly applied sealant.
One example of an improperly applied caulk sealant is a “finger wipe” film of caulk over the seam between the EIFS and a window or door. It is important to note that no water got through the EIFS fascia, it was joint, window and detail failure. Sealant joints are NOT a place to scrimp on EIFS design. Sealant performance is “crucial” to EIFS performance. The Wilmington situation is actual field proof of the necessity for proper caulk joints. The following is a concise summary of typical EIFS manufacturer policy regarding joint sealant application:
- Sealant and joint design is a very important step in EIFS installation.
- Sealant application is a function of the EIFS contractor. If the sealant application is performed by a separate contractor, the EIFS contractor is authorized to inspect the installation, and countersign the inspection checklist.
- All EIF systems will be held back a 3/8″ to 1/2″ (industry standard is 1/2″) from windows, doors and other system penetrations, allowing for a proper sealant isolation joint.
- All soft coat PB installations will be back wrapped where the sealant joint meets the EIFS. The sealant should be bonded to the Base Coat rather than the Finish Coat.
- All sealant joints will use a non-absorbing backer rod (closed cell).
- The sealant must be a quality single component or multi component sealant that is specifically recommended/approved by the applicable EIFS manufacturer.