When it comes to drywall installation, screw length matters — not just for performance, but also for compliance with building codes and manufacturer specifications. Whether you’re installing standard 5/8-inch Type X drywall or specialty panels like QuietRock EZ Snap, one of the most common questions we hear is:
What screw length should I use for 5/8-inch drywall?
Let’s break it down clearly and cite the official sources.
GA-216: The Industry Standard for Drywall Installation
The Gypsum Association’s GA-216 is the ANSI-recognized standard titled “Application and Finishing of Gypsum Panel Products.” It provides detailed instructions on fastener type, spacing, and most importantly — minimum penetration requirements into wood framing.
GA-216 Section 4.6.1:
“Fasteners shall be of sufficient length to penetrate wood framing members not less than 5/8 inch (16 mm)for screws…”
— Gypsum Association GA-216-2021
This means that as long as your screw penetrates 5/8-inch into the wood stud, you’re meeting code. For 5/8″ drywall, a 1 1/4″ screw typically does the job:
- 1 1/4″ screw – 5/8″ drywall = 5/8″ penetration into the stud
So, unless you’re installing over something thick like furring channel or additional layers, 1 1/4″ screws are code-compliant and perfectly acceptable.
Does This Apply to QuietRock EZ Snap?
Yes. QuietRock EZ Snap also follows GA-216.
QuietRock’s product datasheets specify that their panels should be installed in accordance with GA-216 and ASTM C840, which reinforces the same 5/8″ screw penetration rule. That means:
- For single-layer installations over wood studs, 1 1/4″ screws are acceptable
- If there’s furring, hat channel, or other layers between the drywall and framing, you’ll need longer screws — but only to meet the same 5/8” penetration requirement
QuietRock EZ Snap Technical Data Sheet (Product No. 510 & 530):
“Install in accordance with GA-216 and ASTM C840.”
— QuietRock Product Information Sheet
When Should You Use 1 5/8-Inch Screws?
1 5/8″ drywall screws are not always required — but there are common situations where they are:
🔥 Two-Hour Fire-Rated Walls:
- These typically involve two layers of 5/8” drywall
- You’ll need longer screws to reach through both layers and still penetrate 5/8” into the stud
- For example:
- 5/8″ + 5/8″ = 1 1/4″ of board
- 1 5/8″ screw – 1 1/4″ = 3/8″ penetration (not enough)
- In these cases, use 1 7/8″ to 2″ screws to meet code
Refer to UL Design U305, GA File W305, or GA-600 for specific fire-rated assemblies.
📐 Installations with RC Channel (Resilient Channel):
- If you’re mounting 5/8” drywall to resilient channel, you’ll typically use 1 5/8” screws
- These attach through the drywall and channel but only penetrate the channel — not the stud
- The key is matching screw type and length to system specs (RC is a specialty install)
What About Shimmed Studs?
Sometimes individual studs are shimmed slightly to correct framing irregularities. In these cases:
- If shims are thin (1/16″ to 1/8″), 1 1/4” screws still meet the 5/8” penetration rule.
- If thicker materials are used (e.g., full furring strips), then longer screws are needed, but only in those areas.
There’s no requirement to use longer screws across the entire wall just because a few studs are shimmed. Compliance is determined screw by screw, based on actual depth into framing.
Final Answer: What Screws for 5/8” Drywall?
| Installation Type | Screw Length |
|---|---|
| Standard 5/8” drywall to wood studs | 1 1/4” |
| QuietRock EZ Snap 5/8” to wood studs | 1 1/4” |
| 5/8” drywall + resilient channel | 1 5/8” (or per system) |
| 2 layers of 5/8” drywall (fire-rated) | 1 7/8” – 2” |
| Studs with significant furring/shims | Adjust as needed to maintain 5/8” penetration |
Need an Experienced Drywall Installer in San Diego?
At SGP Drywall, we understand the technical details that make or break your project — from fire-rated systems to acoustic drywall like QuietRock. We follow GA-216, ASTM C840, and manufacturer specs on every job.
👉 Visit sdrywallpro.com/drywall-installation to learn more or request a quote.
