Moisture Intrusion Analysis

1. Visual inspection of the structure

The general condition of the construction of the structure's wall cladding will be determined.

The object is to identify and note any problem areas or details that vary from EIFS Industry Member Association (EIMA), EIFS, stucco and manufactured stone veneer (MSV) manufacturer’s guidelines for inclusion in the report.

Deficiencies and departures from standards and guidelines listed below are noted in the report, as well as referencing any pertinent published standards. It can be very helpful to determine both the manufacturer of the cladding system (Dryvit, Sto, Parex, BMI, LaHabra, etc.), and the name of the applicator sub-contractor. Specifications for installation do vary slightly among manufacturers.

Visual only inspection should not be substituted for, or identified as, a Moisture Intrusion Inspection.

Terminations: EIFS EPS foam should be backwrapped, and in barrier (non-drainable) systems, have an expansion type joint where EIFS terminates above a driveway, patio, sidewalk, etc. No such joint is used with moisture drainage systems. All claddings should terminate with adequate clearance above softscape, as well as hardscape. This mainly serves two purposes; it prevents wicking action of moisture into the wall and eliminates a termite path into the structure.  

Roof termination: Should be held off of roof a minimum of two (2) inches and, if EIFS, backwrapped.

Below grade termination: All claddings should terminate above grade, not at or below grade. In EIFS, the foam substrate should be backwrapped and sealed to the foundation approximately 6-8 inches above grade.

Backwrapping: This procedure is unique to EIFS. Termination points of the foam should be backwrapped or should stop at a vinyl termination accessory, in order to provide for proper protection of the foam. Backwrapping also provides for improved attachment of the substrate to the sheathing. There is no backwrapping in stucco.

Backer Rod/Sealant: Windows - Expansion Joints - Grade Terminations: The usage of backer rod and sealant is necessary for the proper construction of isolation and expansion joints.

Expansion Joints: Dissimilar Materials - Floor Bands - Areas of Anticipated Building Movement: Expansion-joints should be used where barrier type EIFS terminates, or meets a dissimilar material with all types of EIFS, stucco and MSV. The typical expansion joint is a flexible, watertight joint utilizing, backer rod and sealant. Expansion joints at the floor bands are usually 3/4 inch in width; typical joint at windows and doors is 1/2 inch. All claddings should include an expansion joint where a building expansion joint exists.

Stucco Control Joints: Not used in EIF systems, monolithic stucco panels should not exceed certain square footages without incorporating control joints to mitigate cracking.

Horizontal Surfaces: Trim Bands/Quoins: There should be no horizontal (flat) surfaces. All surfaces should slope away from the structure at a minimum degree. Best practices avoid the use of stucco and MSV on horizontal surfaces. If used horizontally, special waterproofing procedures should be followed.

Flashing: Flashing should be utilized to properly direct water away from the structure. Doors, windows and deck attachments are the most typical areas where flashing is used. Although flashing has been required for several years, many builders felt that flashing on stucco-type exteriors was not necessary. Flashing points, especially anywhere a roof and exterior wall intersect (where the wall continues past the lower roof-edge and gutter), are common areas for excessive moisture intrusion.

Penetrations: All penetrations should be properly sealed. In addition to pipe penetrations, fasteners, cables or any object that passes through wall-claddings should be sealed.

Damaged Areas: Damaged areas will be noted in the report. Areas that are cracked or damaged should be repaired. In EIFS and hybrid one-coat stucco systems, if the insulation board is not damaged, cladding over the foam board can be reapplied. If there is damage to the insulation board, remove and replace the damaged section of insulation board, and reapply the cladding.

2. Non-Invasive Moisture Detection

The EIFS-clad structure should initially be scanned with a Tramex Wet Wall Detector or equivalent. Non-invasive moisture meters cannot be used on stucco-clad structures. The idea is to scan, or test, areas where moisture is obvious, but also those areas that might not be so obvious, including, but not limited to:

Corners, outside and inside, both faces-minimum every 2 ft.

Around and below doors and windows.

At the band, each floor level, every 3 ft.

At flashing points - sidewall and gutter return areas.

Around all wall penetrations.

It should be emphasized that the scanners available at this time do not provide adequate information for rendering a conclusive Moisture Intrusion Inspection Report.

The technology is limited to providing a basic indication of a possible elevated level of moisture in the area indicated. The areas where the scanner indicates an elevated level of moisture should then be probed using a reliable moisture meter with insulated probes of adequate length.

The use of a non-invasive scanner is not mandatory.

3. Invasive Moisture Testing

Finding a high moisture reading in a sheathing substrate or framing is fairly straightforward. Locating them all, pinpointing their origin, determining the extent of damage and deciding on an effective and cost efficient solution is more intensive. Thus, moisture testing is more complex than it seems. Just about anyone can buy a moisture meter, find a damp area in a wall and tell you to strip off the entire wall, but is that the right call?

Replacing the siding will not solve the problem unless the source of leaking is stopped. If leaks are due to missing flashing and caulking, you can find water problems in any structure, no matter what the siding.

In EIFS-clad buildings, as with most other sidings, water usually enters the wall around penetrations (windows, doors, decks, roof/wall junctures), which are not properly flashed or sealed (caulked). Leaking windows themselves are often the source of water intrusion.

On occasion, a crack, hole or split in the cladding will allow enough water in to cause serious problems. These openings can usually be found at floor lines, at corners of window and door openings, or in aesthetic reveals and control joints.

Sometimes a horizontal or vertical crack will appear in the middle of the wall. The cause and extent of this problem can vary from simple to severe.

The inspector should prepare test probe area(s) as needed by drilling or puncturing the cladding. Holes are made in a pair of two holes (~1/8” diameter 1” apart) in each test location. A typical window will be tested at or below the sill at left and right corners; the center sill will be tested only if either end point provides a high reading, if it is a large window or if there are visual indications of potential moisture intrusion.

After testing, the holes will be filled with a paintable sealant labeled in compliance with ASTM-C920, or of a specific type recommended by the EIFS or cladding manufacturer. Permission for performing the invasive testing must be in writing from the owner in advance.

All sealant must fully cure before having paint applied by others.

4. Reporting

High readings, along with the specific location of the readings, will be noted in the report. This is necessary so that in the future, the readings can be referenced for a follow up test if appropriate. A reference for future testing should be indicated in the report. Time frame should be approximately 6-18 months following initial testing.

The report should indicate the following concerning the readings for wood based products. There is a corresponding range of moisture content for exterior gypsum sheathing:

10 to 15% - Moisture is present in the wall, but is within acceptable range.

16 to 19% - Moisture is present in the wall within an intermediate, but acceptable range.

20 to 29% - The source of the water intrusion should be identified when possible. Appropriate corrective action should be taken to stop the entrance of the water. In many cases, a particular detail may be corrected, or additional sealant installed as a satisfactory corrective measure.

30%+ - This is considered the fiber saturation point of wood; the level at which decay begins to rapidly occur. The cladding at these areas may have to be removed to determine the presence and extent of deterioration or corrosion. Any damaged areas should be repaired or replaced, as necessary.

Areas of 20% moisture content and above will be clearly identified in the report.

Other Types of Inspections

We also provide Air Barrier application inspection and testing.

As with all special inspections, the lowest price is rarely the least expensive in the long term.


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