The NWCB Technical Services Team recently received the following question from one of our Contractor Members-
Can you send us options for typical corner details ? The AHJ is requesting documentation for the detail below
NWCB response-
There are several acceptable configurations for framed gypsum partition corners referenced in the 2021 IBC Table 2508.1, which directs us to GA-216, ASTM C840, and ASTM C754 for installation requirements.
ASTM C754 in particular includes multiple corner options, including the “slider corner” (Fig. 2) and “log corner” (Fig. 3). These are only two of many compliant variations.
ASTM C754 - Slider Corner (Fig. 2)
ASTM C754 - Log Corner (Fig 3)
National Gypsum’s Purple Book includes commonly used corner conditions in its SS-603 (“slider”) and SS-604 (“log”) details, which closely resemble what we typically see on commercial projects. These details are widely accepted by AHJs and comply with the industry installation standards referenced above.
NGC SS-603 – Slider Corner
NGC SS-604 – Log Corner
Both approaches are widely used in commercial construction and are in alignment with the standards referenced in the IBC. Based on these references, your installed corner detail is consistent with recognized industry practice for 2-hour partitions and should satisfy AHJ expectations.