ZumbrunnenWe visited an apartment construction site in the Northeast in April of 2010 and found various fiber cement siding installation problems. Most of the readily apparent problems observed were related to rippling and uneven lapping of planks. For example, at 2:00 pm, the afternoon shadows cast rippled shadows on the lapped siding.  The problems on this particular wall were evident. However, in the morning, this same wall is in the shade and the problems cannot be seen as easily. These issues are showing up around the entire work site and can be observed at various times of the day.

In the Owner/Architect/Contractor meeting, we notified the team of our concerns and passed around digital photographs of the worst problems. The contractor initially was defensive, but subsequently agreed to follow up with the architect and the manufacturer’s representative; they are committed to doing an exemplary job on this project.

After the meeting, the owner reported to us that there are serious fiber cement siding deterioration problems at one of their other Northeast properties.  The problems typically occur near grade and around nails; apparently the panels are pulling nails out due to constant thermal expansion and contraction action.

Research on the Internet reveals “the many styles of fiber cement panels have slightly differing attachment techniques specified by the manufacturer.  Fiber cement siding is often blind nailed, the nails are actually hidden by the overlapping lap siding plank.”

The architect on this project complained that manufacturer’s instructions were difficult to keep up with due to ongoing changes in the products and the evolution of installation techniques.  We checked this manufacturer’s website and found that the fiber cement siding lap siding instructions were last updated in April of 2009.

A January 2010 technical support bulletin concerned with expansion characteristics of fiber cement panels provided the thermal expansion characteristics of the manufacturer’s various products and the following statements:

“It is the responsibility of the Licensed Design Professional, when using our components as part of the assembly to:

* Adhere to all the installation requirements listed in the relevant product installation instructions.

* Design a wall assembly that actively manages moisture considering both interior and exterior environments of the building, particularly in buildings that have a high risk of wind-driven rain penetration, that are artificially heated or cooled, or (that) contain indoor pools/spas.

* Understand the interaction between system components.

Please be advised the manufacturer provides a limited transferable product warranty covering the product only. The manufacturer is not responsible for system design or installation.”

These statements at first appear reasonable.  However, upon further reflection, they suggest to us the possibility of an increasing number of complaints associated with this type of product.  In our experience, project specifications and design drawings do not provide installation details; they direct the installer to adhere to the manufacturer’s instructions.   This is appropriate, even though products may appear similar, they often have unique or changing installation requirements.  Unfortunately, it is also our experience that contractors frequently fail to check for the appropriate installation requirements. Therefore, to ensure proper installation, the owner’s representative should verify that the contractor is following the correct version of the manufacturer’s requirements by contacting the manufacturer and determining which instructions are appropriate for the materials purchase for the project.  A review of construction documents, including shop drawings and material submittals, prior to construction should be conducted to ensure compliance.

There is a lot of praise on the Internet for fiber cement panel systems; we believe it is a superior product when properly stored, installed, and maintained, provided there are not inherent problems in manufacturing by the supplier.  Judging from the growing number of complaints noted on the Internet, and those we have witnessed, installers are not always properly storing the material on the shipping pallet as required by the manufacturer, nor are they following all of the manufacturer’s installation requirements.   Additional problems can occur when subsequent contractors, such as the grading and landscape contractors, allow backfill or landscape to come in contact with the siding.  Architects may not provide adequate framing for nailing of the siding.  Owners may not properly maintain all related component’s of the building.

Beware, there are contractors who claim to be experts, but no one is an expert unless they know and adhere to the details. Should your installation go wrong, do not hesitate to call in the manufacturer’s representative to help identify and resolve the problems.  The manufacturers that we have dealt with stop short of acknowledging any flaw in the design of their product, but will be willing to point out installation shortcomings.  We also need to remember that their warranty only applies to failed product that has been properly stored, installed, and maintained.

As an update, the first representative from the manufacturer visited the site in April of 2010.  We will return to the site near the end of April, and on our next posting, will review his findings and next steps.

zumBrunnen, Inc.
Atlanta, GA

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