Chapter 2 Understanding The Problem What Causes Most Of The Problems With Stucco? EIFS was originally intended to seal and insulate the exterior of the home from the elements. Problems occur when poorly installed or missing caulking and flashing allow water to leak into the space behind the system. Since the systems were designed to keep moisture out, moisture that does penetrate the system has no way to escape and remains trapped within the wall. Many stucco systems have never been caulked and are missing important flashings that can prevent the majority of moisture from penetrating the system. Windows have proven to be a major source of moisture penetration in stucco homes due to gaps or cracks in their construction. Double hung windows are typically the worst type of window for allowing moisture into the wall cavity. It is important to remember that even a little moisture can present a substantial risk since it can sometimes take many months for the moisture to dissipate from a stucco system. Typically, moisture will continue to penetrate the stucco before the existing moisture has had enough time to dry out. This causes the support wood to be exposed to moisture on a continuous basis, which eventually will cause the wood to rot. Hardcoat stucco does not seal the home as thoroughly as EIFS, and some of the moisture that penetrates the system is able to evaporate through the hardcoat stucco itself. However, hardcoat stucco will tend to have almost identical problems to EIFS. Flashing locations and windows can allow moisture to enter the wall cavity thereby damaging the structural wood. When moisture regularly penetrates the hardcoat stucco, the wood structure behind the stucco often remains wet on a continuous basis. The constant presence of this moisture causes the wood to eventually rot. Are Stucco Homes The Only Homes With Moisture Problems? No. It is important to remember that moisture problems found in stucco homes are often present in homes clad with brick, wood, vinyl and other claddings. Because it is more difficult to test these types of homes for moisture, it is incorrectly assumed that these homes don t have the potential for moisture problems. Moisture does more damage to all homes in the United States than fire, termites, flooding and other types of damage combined. All homes should be inspected to assure that the proper protection from moisture is in place. 9
The items listed on the following pages are problems that have been common to stucco applied to residential woodframed dwellings throughout the United States. Almost all homes with stucco will experience problems with at least one of the following areas, and homes with other types of cladding often experience similar problems: Around The Perimeter Of The Window or Door Areas around windows and doors where the stucco terminates against the window trim or molding should be sealed with a proper caulk joint to prevent moisture penetration. MoistureFree requires an effective caulk joint, but does not require a backer rod joint, which is typically specified by the manufacturer during the original installation of the system. About 10% of the leaks associated with windows and doors are caused by improper sealant joints around the exterior of the window or door. Within The Construction Of The Window or Door Approximately 90% of the leaks associated with windows and doors are caused by leaks within the construction of the window or door unit. The arrows above are pointing to the sash tracks of the window. This area is likely to allow water to pass through the window if not properly sealed. MoistureFree requires that all construction elements of windows and doors be properly sealed. Sash Jamb Sill Sash Track Miter Joint Wood damage and open crack at miter joint The Miter Joints of Windows and Doors The miter joint is the intersection of the sill and the jamb of the window. If this area of the window is not properly sealed, water can pass directly into the wall cavity behind the stucco system. This type of leak can occur on all types of windows and homes including brick, wood and other sidings. Behind The Sash Track at the Miter Joint A sash track is found on double and single hung windows with sashes that move up and down. The area behind the sash track is typically not sealed or treated for moisture. MoistureFree requires that the bottom 6 behind the sash track be sealed properly. This photo shows wood rot behind a sash track that is not sealed. Water that gets to this area will go directly into the wall cavity. 10
The Most Common Problems With Stucco Windows (cont.) Damage to window casing and molding Wood Rot In Windows Wood windows that are already severely damaged by rot cannot be effectively repaired using just caulking. The damaged wood must be repaired or the window must be replaced. Once the wood damage is repaired, a proper caulk joint can be installed. If the window is going to be replaced, make sure that proper flashing is in place before the window is re-installed. See Section 4.4 for flashing details. Damage To Top Of Window Or Door Much of the damage that occurs at the top of windows and doors is caused by leaks in other windows above the damaged window or leaks from another source, such as a missing kickout flashing. Many windows were installed without head flashings which help protect the top of the window. MoistureFree does not require the retrofitting of head flashings unless it appears that such a flashing would solve a particular moisture problem. Glazing failure location High moisture area Sliding Glass and French Doors Miter joints, thresholds, glazing and other elements of the door s construction should be investigated to assure that no moisture is penetrating into the wall cavity be- Custom Oversized Windows Areas below some oversized custom windows may experience moisture problems. This is typically caused by a failure of the glazing caulk which seals the glass to the window molding. If these windows leak, they can damage the support header directly below the window. Caulking of the window or installation of a window pan will typically solve the problem. 11 Miter joint at the threshold and jamb Thresholds joints and screw hole leaks
The Most Common Problems With Stucco Caulking Missing Caulk Joint Effective Caulk Joints All breaches in the stucco systems must be properly sealed. MoistureFree requires that the caulk joint appear to be functioning properly, uses proper caulking material and is of a design specified in the MoistureFree Repair Standards and Options. Failing Caulk Joints Any breach in the stucco system that is not properly sealed must be modified to comply with the standards established in the MoistureFree Repair Standards and Options. Like the photo above, many areas around windows and doors have no caulk joint at all. Failing Caulk Joints All joints in the exterior of the home should be properly sealed. The joint shown above is within the construction of a door, but can allow moisture to penetrate into the wall below. Improper Use Of Caulk As Wood Filler Caulking is not intended to be used as a wood filler and will quickly fail once the caulking cures. The wavy areas in the picture above show where the wood rot was filled with caulk and then painted to hide the damage. 12
The Most Common Problems With Stucco Kickout Flashings Proper Kickout Flashing (required) Proper Roof Termination (recommended, not required) Roof/Wall Intersections Missing Kickout Flashing The area marked with an x indicates a missing flashing called a kickout. When this flashing is missing, water that runs along the edge of the roof can penetrate behind the system and go directly into the wall behind the stucco system. Since this area is often exposed to high volumes of water when it rains, it is critical that a kickout flashing be installed. About 65% of the moisture-related structural damage that affects stucco homes occurs at missing kickout locations. Properly Installed Kickout Flashing The photo above shows a properly installed kickout flashing. Water that runs along the edge of the roof will reach the kickout flashing and be directed away from the wall and into the gutter or off the edge of the roof. This photo also shows that the stucco system is raised off the roof by 2. This is a proper termination of the stucco system which allows the free flow of the water along the edge of the roof. This detail is recommended, but is not required by MoistureFree to qualify for warranty coverage. Improper Kickout Flashings Exterior Mount Improperly installed kickout flashings will not protect the wall and may make the moisture problems worse. The photo above shows a piece of flashing mounted to the exterior of the wall which does not stop moisture from entering the wall cavity. A proper kickout flashing must be installed behind the step flashing and stucco system. MoistureFree requires properly installed and constructed kickout flashings. Improper Kickout Flashings Improper Seal The kickout shown above does not allow for proper water flow away from the wall. Also, the backside of the kickout is not sealed and has a hole which could allow water to enter into the wall. A properly installed kickout requires a skilled installer who is familiar with the important details necessary to make the flashing perform properly. 13
The Most Common Problems With Stucco Deck Flashings Minimum Required Deck Flashing Deck Joist Flashings Missing (recommended, not required) Deck Flashings Missing Attached decks which are not properly flashed can allow moisture to penetrate into the wall below the deck. There is also a structural failure risk if proper flashings are not in place to protect the framing of the deck to the framing of the house. MoistureFree requires that deck flashing be present and that it provide protection for both the cladding and the structural wood of the deck. Minimum Required Deck Flashing MoistureFree requires that some minimal deck flashing must be present to qualify for warranty standards. The flashing shown above was tested and was providing adequate protection of the wall and framing wood. However, properly installed flashing would also run behind the support joist of the deck and exit below the deck joist band. Also, deck flashing should have at least 1/2 high end dams which prevent water from entering the wall at the side termination of the flashing. Top View of Proper Flashing Proper flashing should be visible from the top of the deck between the deck boards if the deck boards are running perpendicular to the house. Deck boards that run parallel to the house may hide the flashing from the top. Flashing should be viewable from beneath the deck. Proper Flashing Deck Joist Band The deck joist band supports the weight of the deck and is attached directly to the joist band of the house. Proper flashing should exit from under the deck joist band. Also, it is important to verify that the deck joist band is properly attached to the home and that no rotting of the wood is visible around the attachment bolts. 14
The Most Common Problems With Stucco Chimneys Chimney Caps A proper chimney cap should overlap the entire top of the chimney to prevent water from leaking into any openings at the top of the chimney. MoistureFree requires that a functional chimney cap be installed on the home. Missing kickout location on both sides of the chimney chase. Missing Kickouts When a roof slopes towards a chimney and terminates in the middle of the chimney chase, a kickout flashing is required. These areas should be thoroughly inspected for moisture below the kickout location and at the bottom of the chimney chase where moisture may collect. Chimney Cricket The sloped detail on the back side of the chimney shown above is called a cricket. A cricket is designed to help direct water away from the chimney in order to reduce the chance of leaks occurring from the impact of the water running off the roof. MoistureFree may require a cricket if there appears to be a problem at this location. Missing Chimney Cap and Improper Use of Stucco This chimney is missing a chimney cap and has stucco incorrectly used to seal the top of the chimney. A proper chimney cap would be required on this home in order to qualify for warranty coverage. 15
The Most Common Problems With Stucco Porches and Stoops Missing Sealant And Flashing Proper Porch Termination With Flashing Porch Missing Proper Sealant Joint or Flashing Many porches and stoops are built after the home is completed. Settling and movement often causes gaps to occur between the attachment and the home. A proper sealant joint or flashing should be installed to prevent water from draining between the house and the porch. Also, EIFS which is trapped between the home and the porch may need to be removed in order to prevent pest infestation. Proper Termination and Flashing Proper sealing and flashing of the porch or stoop areas will prevent water from damaging the framing wood of the home. In areas that freeze regularly, proper flashing prevents moisture from freezing and expanding behind the porch which can damage the porch and the stucco system. The Most Common Problems With Stucco Flat Accents Properly Caulked Flat Accent Flat Accents Must Be Properly Sloped or Sealed Accents which protrude from the surface of the stucco must be sloped to allow for drainage or sealed to prevent leaks. The photo above shows a flat accent which is caulked along the edge of the window sill. This type of caulk joint will typically prevent moisture from leaking behind the system. Properly Sloped Accents Properly Sloped Accents Accents should be sloped to allow for proper drainage. However, retrofitting proper slopes is very expensive and is often not necessary to prevent moisture intrusion. Most flat accents can be protected by simply sealing or caulking the top side of the accent. 16
The Most Common Problems With Stucco Columns Proper Flashing Should Be Present Improperly Flashed Column If a support or accent column is not properly flashed to prevent moisture entering through the top of the column, then moisture will pool at the bottom of the column can cause wood rot inside the column. If the bottom of the column is tightly sealed, this can make the problem worse. This photo shows a column cut open to reveal extreme wood rot inside. Improper Flashing At Column Head Columns wrapped with EIFS should be properly flashed on top and at intersections with other framing. Columns that are used for structural support should be checked carefully for moisture and damage. The Most Common Problems With Stucco Hose Bibbs Open Cracks Around Bibb Properly Sealed Bibb Hose Bibb Leaks Hose bibbs should be secured to prevent excessive movement when used and caulked to prevent leaking. Leaking hoses can cause high volumes of moisture to enter at these locations. Properly Sealed Hose Bibb Caulking around the hose bibb will stop most leaks provided that the caulking doesn t fail when the faucet is used. 17
The Most Common Problems With Stucco Utility Connections Utility Connection Breaches Electrical, gas, cable, telephone and other breaches in the system should be properly sealed to prevent moisture and pest problems. Proper Utility Caulking Any breaches made in the system should be sealed to prevent moisture and pests from entering the home or the stucco system. The Most Common Problems With Stucco Exhaust Vents Properly Sealed Vent Improperly Sealed Vent Vents for clothes dryers or HVAC systems should be sealed. Properly Sealed Vent Caulking around all vents is required. 18
The Most Common Problems With Stucco EIFS Below The Ground Proper termination of the EIFS to prevent pest problems. Termite Band This area has had the EIFS removed below the ground and cut up 6. Improper Termination EIFS should never be continued under the soil and should be properly terminated at least 6 to 8 above grade. This photo shows where the EIFS is not properly terminated which can allow termites and ants to enter the home through the insulation element of the EIFS. A proper above grade termination will eliminate this problem. Proper Termination-Termite Band The foam insulation component of the EIFS is cut away and the base and finish coat is applied back to the foundation. MoistureFree strongly recommends that a termite band be installed, but does not require it for warranty protection. However, most pest control companies will require a termite band in order to qualify for a termite bond. Dead Valley Locations Dead Valley Locations A dead valley is a location on the roof where no slope is provided to allow for water drainage. If these areas are not properly flashed, water can penetrate the wall and enter the home. This photo shows a properly installed 10 high dead valley flashing which should adequately protect the wall. Automatic Sprinkler Overspray Automatic sprinkler systems should be checked regularly to ensure that no water is spraying on the home. Sprinkler overspray can substantially increase the likelihood of a moisture problem. 19
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