Question? Just ask us!
Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair
InspectAPedia ® Home
EXTERIORS of buildings
ADHESIVES, EXTERIOR CONSTRUCTION
AGE of a BUILDING - how to determine
ALGAE, FUNGUS, LICHENS, MOSS
ARCHITECTURE & BUILDING COMPONENT ID
ATTIC CONDENSATION CAUSE & CURE
BARK SIDE UP on DECKS & STEPS
BASEMENT WALKOUTS & COVERS
BEST CONSTRUCTION PRACTICES GUIDE
BRICK VENEER WALL LOOSE, BULGED
BRICK WALL DRAINAGE WEEP HOLES
BOOKSTORE - EXTERIORS
CAULK GUN TYPES, CHOICES
CAULKS & SEALANTS, EXTERIOR
CHIMNEY INSPECTION DIAGNOSIS REPAIR
COLUMNS & POSTS, DEFECTS
CONNECTORS, FASTENERS, TIES
DECK & PORCH CONSTRUCTION
DECK COLLAPSE Case Study
DECK FINISHES COATINGS PRESERVATIVES
DECK FLASHING LEAKS, ROT Case Study
DEFINITIONS of ENGINEERED WOOD OSB LVL etc
DRYWELLS, FRENCH DRAINS for FLAT SITES
EARTHQUAKE DAMAGED FOUNDATIONS
EIFS & STUCCO EXTERIORS
ENGINEERED WOOD Products
EXTERIOR WALL SIDING TRIM & FINISHES
FIBERGLASS INSULATION MOLD
FLASHING, ASPHALT SHINGLE VALLEYS
FLASHING, CHIMNEY Mistakes & Leaks
FLASHING, CLAY TILE ROOFS
FLASHING MEMBRANES PEEL & STICK
FLASHING for METAL ROOFS
FLASHING ROOF WALL DETAILS
FLASHING ROOF-WALL SNAFU
FLASHING SIDING DETAILS
FLASHING WALL DETAILS
FLASHING WINDOW DETAILS
FLASHING WOOD ROOF DETAILS
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FOOTING & FOUNDATION DRAINS
FOUNDATION CRACKS & DAMAGE GUIDE
GALVANIC SCALE & METAL CORROSION
GLUES ADHESIVES, EXTERIOR CONSTRUCTION
GRADING, DRAINAGE & SITE WORK
GUTTERS & DOWNSPOUTS
HEAT TAPES & CABLES for ROOF ICE DAMS
HOUSE PARTS, DEFINITIONS
HOUSEWRAP / SHEATHING WRAP
HOUSEWRAP INSTALLATION DETAILS
HOUSEWRAP PRODUCT CHOICES
HOUSEWRAP at SILLS, SOLES, TOP PLATES
HUMIDITY LEVEL TARGET
ROOF ICE DAM LEAKS
INDOOR AIR QUALITY & HOUSE TIGHTNESS
INSECT INFESTATION / DAMAGE
LEAD POISONING HAZARDS GUIDE
LEAD TEST KIT for HOME USE
LEED GREEN BUILDING CERTIFICATION
LOG HOME GUIDE
MOISTURE CONTROL in BUILDINGS
MOISTURE PROBLEMS: CAUSE & CURE
MOLD DETECTION & INSPECTION GUIDE
MVOCs & MOLDY MUSTY ODORS
ODORS GASES SMELLS, DIAGNOSIS & CURE
PAINT & STAIN GUIDE, EXTERIOR
PAINT FALURE, DIAGNOSIS, CURE, PREVENTION
PAINT FAILURE DICTIONARY
PAINT SURFACE PREPARATION
PORCHES & Sunrooms
PORCH CONSTRUCTION & SCREENING
RAILINGS, DECK & PORCH
RETAINING WALL DESIGNS, TYPES, DAMAGE
RETAINING WALL GUARD RAILINGS
ROOF ARCHITECTURAL STYLES - PHOTO GUIDE
ROOF CLEANING RECOMMENDATIONS
ROOF COLOR RECOMMENDATIONS
ROOF DORMER TYPES - PHOTO GUIDE
ROOFING DIAGNOSIS INSPECTION & REPAIR
ROT RESISTANT LUMBER
ROT, TIMBER FRAME
ROT, TIMBER ASSESSMENT
SEARS KIT HOUSES
SEPTIC & CESSPOOL SAFETY
SHEATHING, GYPSUM BOARD
SHEATHING, FOIL FACED - VENTS
SIDING TYPES, INSTALLATION, DEFECTS
SINKHOLES, WARNING SIGNS
SOUND CONTROL in buildings
STAINS on & in BUILDINGS, CAUSES & CURES
STAINS on CONCRETE
STAIN DIAGNOSIS on BUILDING EXTERIORS
STAIN DIAGNOSIS on BUILDING INTERIORS
STAINS & FINISHES, INTERIOR
STAINS on INDOOR SURFASCES, PHOTO GUIDE
STAINS & Thermal Tracking
STAIN DIAGNOSIS on ROOFS
STAINS on STONE, DIAGNOSE & CURE
STAIRS, RAILINGS, LANDINGS, RAMPS
STONE SURFACE CLEANING METHODS
STRESS SKIN INSULATED PANELS
STRUCTURAL DAMAGE PROBING
STUCCO WAll FAILURES DUE TO WEATHER
STUCCO WALL METHODS & INSTALLATION
STUCCO OVER FOAM INSULATION
STUCCO PAINT FAILURES
SURFACE GRADING, SITE DRAINAGE
TEST KITS for DUST, MOLD, PARTICLE TESTS
THERMAL EXPANSION CRACKS in BRICK
THERMAL EXPANSION of MATERIALS
THERMAL IMAGING, THERMOGRAPHY
THERMAL IMAGING MOLD SCANS
THERMAL MASS in BUILDINGS
TRIM, EXTERIOR CHOICES, INSTALLATION
TRIM, INTERIOR INSTALLATION
TRAPPED MOLD BETWEEN WOOD SURFACES
TRUSS UPLIFT, ROOF
TRUSSES, FLOOR & ROOF
VAPOR BARRIERS & CONDENSATION in BUILDINGS
VENTILATION in BUILDINGS
VINYL CHLORIDE HEALTH INFO
VINYL SIDING or WINDOW PLASTIC ODORS
VOCs VOLATILE ORGANIC COMPOUNDS
WALL SIDING TRIM & FINISHES
WALL FINISHES INTERIOR
WALL CONSTRUCTION BARRIER vs CAVITY
WATER BARRIERS, EXTERIOR BUILDING
WATER ENTRY in BUILDINGS
WIND ENERGY SYSTEMS
WIND TURBINES & LIGHTNING
WINDOWS & DOORS
WINTERIZE A BUILDING
WOOD-OIL COMBINATION HEATERS
WOOD STOVE OPERATION & SAFETY
ZONE VALVES, HEATING
EIFS Drainage systems:
This article discusses in-wall drainage systems introduced to avoid moisture and mold problems in EIFS synthetic stucco wall systems, and the role of weather and moisture in stucco wall installation, durability, and painting success.
This article series discusses best practices construction details for building exteriors, including stucco exteriors, exterior caulks and sealants, and choices and application of exterior finishes on buildings.
Green links show where you are. © Copyright 2015 InspectApedia.com, All Rights Reserved.
Continuing from from Best Practices Guide to Residential Construction we discuss the introduction of drainage systems intended to reduce or avoid these EIFS difficulties.
In response to these problems, most EIFS manufacturers have introduced new “drainage” or “water-managed” systems, which require the same type of waterproof drainage plane found behind traditional stucco systems (see Figure 1-30)
[Click to enlarge any image]
As with traditional stucco, layered building paper or plastic housewrap protects the framing and sheathing, and all exterior openings and penetrations are flashed to conduct any water to the outside of the sheathing wrap.
Since window leakage was the single biggest contributor to EIFS failures, pan flashing is recommended at windows.
Rather than gluing the EPS foam to the sheathing, the new drainage EIFS typically use mechanical fasteners and are designed with a capillary break between the back of the EPS and the sheathing wrap to promote drainage.
Some EIFS contractors use special corrugated or wrinkled sheathing papers to create the drainage space, while others have vertical grooves cut into the back face of the foam insulation.
In all cases, the drainage plane leads to a perforated weep flashing at the foundation to drain away any trapped water.
The backup drainage layer, however, should not provide an excuse for sloppy workmanship on the exterior skin. The new kinds of EIFS should still be made as waterproof as possible, since any water that leaks past the skin may be slow to dry out. EIFS consultant Russell Kenney, who has worked with these systems for nearly 20 years, recommends exceeding the minimum specs required by EIFS manufacturers.
On the other hand, our EIFS damage photograph (left) shows how water or moisture traps can form in an EIFS wall even in a building interior, leading to substantial damage. (Photograph courtesy of home inspector John Rudy).
Kenney recommends a higher-density EPS foam with only 2% water absorption by volume instead of the 4% allowed by ASTM C584. In addition, Kenney recommends a heavier 6-ounce reinforcing mesh versus the typical 3-ounce cloth, as well as special high-impact mesh in high-traffic areas.
He also recommends a 3/32-inch base coat applied in two layers, with the first layer used to partially embed the fiberglass reinforcing and the second layer to fully cover and protect it.
These steps will significantly improve the impact resistance of EIFS, but it is still less durable than traditional stucco or thin-coat stucco.
See details about the cause, diagnosis, cure, or prevention of paint failures on stucco exterior walls, found at STUCCO PAINT FAILURES.
As with the original barrier EIFS, all penetrations require a high-quality elastomeric sealant. The sealant needs to be applied to the base coat since the finish coat tends to soften when wet, providing a poor substrate for sealant. For the caulk joints to last, they must be wide enough to tolerate the anticipated movement, typically 3/8 to 1/2-inch, and backed up by backer rod (see “Joint Design,” page 37 in Best Practices Guide to Residential Construction).
While control joints are generally not needed along the length of the wall—unless it exceeds 75 feet and is in direct sun—they are required between floors on multistory buildings. Silicone sealant is recommended at all joints for its longevity and flexibility in cold temperatures.
In theory at least, drainage EIFS should function the same as any other exterior cladding systems. Any water that manages to penetrate the outer skin should be stopped by the drainage layer and safely drained away. However, given the low permeability of polymer-based coatings and the tendency of EPS foam to soak up and hold water, EIFS are best avoided in residential projects unless high-quality workmanship and regular maintenance of sealants can be assured.
-- Adapted with permission from Best Practices Guide to Residential Construction.
Continue reading at STUCCO OVER FOAM INSULATION or select a topic from the More Reading links shown below.
Suggested citation for this web page
Green link shows where you are in this article series
Frequently Asked Questions (FAQs)
No FAQs have been posted for this page. Try the search box below or CONTACT US by email if you cannot find the answer you need at InspectApedia.
Questions & answers or comments about the requirement & methods for installing wall drainage systems behind synthetic stucco wall coverings.
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
Search the InspectApedia website
HTML Comment Box is loading comments...
Technical Reviewers & References