Types of Stucco Installations
Hard Coat System Components
- A Moisture Barrier is required on top of moisture sensitive substrates
- Three coats or layers with a total thickness of 3/4 of an inch or more
- Scratch Coat, Brown Coat, and Finish Coat
- Metal Accessories - Casing Beads, Stops or Grounds.
- Corner beads and Control Joints or Expansion Joints at 144 square feet
- Flashings are required as a part of weatherproofing the system
Hard Coat Stucco (HCS), in one form or another, has been in use for centuries. Many ancient civilizations had their own formula for making this exterior plaster product. Hard Coat Stucco has a long history in America that is well accepted and defined in Model Building Codes.
EIFS(Exterior Insulation and Finish System) Components
- A weather resistant layer is applied
- EPS (Expanded Polystyrene) insulation properly attached to substrate
- EPS properly prepared to receive basecoat.
- Polymer Based basecoat applied to EPS.
- Fiberglass mesh immediately embedded into fresh basecoat.
- Finish Coat properly applied to cured basecoat.
- Edges must be properly back-wrapped to protect the EPS and minimize damage.
- Details have developed over the past 30 years by the manufacturers.
EIFS is a non-load bearing exterior wall system, therefore the system's primary function is to provide a weather barrier, thermal insulation, and an attractive exterior cladding. When properly installed and maintained, the system will provide many years of beauty and function
Moisture Intrusion can Occur Anywhere Stucco Meets a Dissimilar Material
Things to look for
- Peeling paint, evidence of water damage on the interior wall, staining on the exterior
- Check for caulking around windows, doors, utility penetrations
- Stucco manufacturers recommend a specific sealant for their products
Flashing
- Flashings at appropriate places direct water away from the house
- Missing, improper or unsealed flashings where roof lines terminate into an EIFS or Hard Coat stucco wall will allow roof run-off to be dumped directly behind the stucco
- Water must be directed away from windows, decks, gutters, etc.
Caulking
- Penetrations in the EIFS or Hard Coat stucco at decks, hose bibs, dryer vents, light fixtures, satellite dishes, etc., must be properly sealed with the appropriate sealant
- All joints where EIFS or Hard Coat stucco meets a dissimilar material must be sealed with the appropriate sealant
- Existing sealants should be adhered, soft and flexible
Installation Issues
- Foam insulation should be at least 3 inches above soft grade and two inches above hard surfaces. This prevents wicking of moisture and eliminates a termite path into the structure.
- The foam substrate should be properly back-wrapped in order to provide for proper protection of the exterior system.
- EIFS used on non-vertical surfaces such as trim and decorative accents should have a sloping surface to prevent standing water.
- The use of fiber in hard coat stucco mixtures will help prevent cracks in the stucco and moisture intrusion.