What type of fasteners are not allowed for decorative trim on EIFS?

When it comes to the installation of decorative trim on Exterior Insulation and Finish Systems (EIFS), the use of fasteners is critical to ensuring the integrity and longevity of the system. Face nails are considered inappropriate for this application because they can compromise the waterproofing and insulation properties of EIFS. These nails can create penetrations in the system that allow moisture to enter, which can lead to deterioration or damage to the underlying structure.

The installation guidelines for EIFS specifically recommend against face nails as they do not provide a secure, moisture-resistant attachment for the trim. Instead, other fastening methods that do not penetrate the system directly are preferred, ensuring that the aesthetic elements are securely attached without risking the performance of the EIFS.

In this context, the other options may be alternatives that are acceptable under different conditions or applications, but specifically, face nails are not suitable for decorative trim on EIFS due to moisture concerns and potential damage to the system's integrity. Therefore, the choice that identifies face nails as not being allowed is correct.