Drilled or notched studs raise two questions: Does the framing meet code as it stands, and if it doesn’t, what correction is acceptable?
Not every drilled or notched stud needs reinforcement. Some holes require doubled studs. Cuts outside the prescriptive limits need a correction supported by the applicable code or an approved design. Installing a metal plate or stud shoe does not, by itself, establish compliance.
This article explains the limits for conventional 2×4 and 2×6 wall studs, the difference between drilling and notching, and where approved stud shoes fit into the evaluation.
The code basis is 2021 IRC Section R602.6. The stud-drilling requirements discussed here are unchanged in the 2024 IRC.
Always verify the code edition and local amendments adopted for your project.
Start With the Wall and the Material Removed
Before selecting a repair, identify the condition:
- Is the stud in an exterior wall, an interior bearing partition, or an interior nonbearing partition?
- Is the opening a bored hole or a notch?
- What is the actual stud depth?
- How much wood was removed, and where?
An interior wall is not automatically nonbearing. A 2×6 wall is not automatically bearing. Also, exterior walls fall under the exterior-wall provisions even when they are nonbearing.
When the wall’s function is uncertain, review the framing plans and load path. See How to Read a Framing Plan for help identifying what the framing supports.
The examples below use conventional studs installed on edge: 3½ inches deep for a 2×4 and 5½ inches deep for a 2×6. They address holes bored through the stud’s 1½-inch thickness and notches cut into its depth.
Top plates, floor joists, rafters, and engineered framing products require their own evaluation.
Drilling and Notching Have Different Limits
2021 IRC Section R602.6 addresses both conditions, but the allowable percentages are different.
| Condition | Percentage of stud depth | 2×4 measuring 3½ inches deep | 2×6 measuring 5½ inches deep |
|---|---|---|---|
| Maximum notch depth in an exterior wall or bearing partition | 25% | ⅞ inch | 1⅜ inches |
| Maximum notch depth in an interior nonbearing partition | 40% | 1.40 inches | 2.20 inches |
| Maximum bored-hole diameter in an exterior wall or bearing partition without triggering doubling | 40% | 1.40 inches | 2.20 inches |
| Maximum bored-hole diameter in an exterior wall or bearing partition with the required doubling and successive-stud limitation | 60% | 2.10 inches | 3.30 inches |
| Maximum bored-hole diameter in an interior nonbearing partition | 60% | 2.10 inches | 3.30 inches |
These are the prescriptive limits without using the approved stud-shoe exception. Other hole-location requirements still apply.
Do not apply the 60% drilling allowance to a notch. Likewise, the provision permitting larger holes in doubled studs does not establish an equivalent allowance for deeper notches.
Example: A 1-Inch Notch in a 2×4
In an exterior wall or bearing partition, the notch limit is:
3.50 × 25% = 0.875 inch, or ⅞ inch.
A 1-inch notch exceeds that limit.
In an interior nonbearing partition, the limit is:
3.50 × 40% = 1.40 inches, or 1⅜ inches when rounded down to the nearest sixteenth.
The same 1-inch notch falls within that depth limit. The wall condition changes the answer.
What Drill-Bit Sizes Fit the Limits?
Percentages establish the requirement. Bit sizes help translate it into field use.
| Stud size | Hole limit without doubling in an exterior or bearing wall | Example bit within that limit | 60% hole limit | Example bit within that limit |
|---|---|---|---|---|
| 2×4, 3½ inches deep | 1.40 inches | 1⅜ inches | 2.10 inches | 2 inches |
| 2×6, 5½ inches deep | 2.20 inches | 2³⁄₁₆ inches | 3.30 inches | 3¼ inches |
The 60% column applies to interior nonbearing partitions or to exterior walls and bearing partitions where the required doubling and successive-stud limitation are satisfied.
These are example bit sizes, not sizes mandated by code. Evaluate the finished hole.
Do not round the maximum upward:
- A 2⅛-inch hole is 2.125 inches, exceeding 60% of a 3½-inch-deep stud.
- A 3⁵⁄₁₆-inch hole is 3.3125 inches, exceeding 60% of a 5½-inch-deep stud.
For the detailed 2×4 examples, see How Big a Hole Can You Drill in a 2×4 Stud?.
When Does Drilling Require Doubled Studs?
In an exterior wall or bearing partition, a hole over 40% of the stud depth triggers doubling under R602.6. The hole must remain within 60%, and no more than two successive doubled studs may be so bored.
For example, a standard 2×6 stud measures 5½ inches deep. A 3-inch hole is approximately 54.5% of that depth.
Because it exceeds 40%, the stud must be doubled in an exterior wall or bearing partition under this provision. The hole remains below the 60% maximum.
In an exterior wall or bearing partition, that hole requires doubling under the prescriptive provision. In an interior nonbearing partition, that diameter does not trigger doubling under this section.
Doubling does not make every hole acceptable. A hole above 60% remains outside this prescriptive allowance, even when the stud is doubled.
Hole Location Can Still Cause a Failure
R602.6 also requires:
- At least ⅝ inch from the edge of the hole to the edge of the stud.
- No bored hole in the same section as a cut or notch.
A centered 3-inch hole in a 5½-inch-deep stud leaves:
(5.50 − 3.00) ÷ 2 = 1.25 inches on each side.
That exceeds the ⅝-inch minimum. Move the hole toward one edge, however, and the clearance can become insufficient.
Diameter, doubling, and location are separate checks. Passing one does not establish compliance with the others.
Can a Stud Shoe Make an Oversized Hole or Notch Acceptable?
R602.6 includes this exception:
“Where approved, stud shoes are installed in accordance with the manufacturer’s instructions.”
That permits an approved stud-shoe solution. It does not establish one universal repair for every damaged stud.
For a specific example, Simpson Strong-Tie’s ICC-ES report ESR-2608, reissued February 2026, addresses its SS and HSS stud shoes under both the 2021 and 2024 IRC.
The report states that when the cut, notch, or drilled hole exceeds the code maximums, use of these shoes requires a submitted engineered design under the applicable provision. For the IRC, the report references R301.1.3.
The report also distinguishes the products:
| Product | Capacity identified in ESR-2608 |
|---|---|
| SS stud shoe | Compression |
| HSS stud shoe | Compression and tension/uplift |
Its tables provide model-specific fasteners and allowable loads. Product selection must account for those conditions; physical fit alone is insufficient.
See ICC-ES Evaluation Report ESR-2608 for the complete conditions.
Don’t Assume a Shoe Fits Every Pipe or Opening
Simpson’s HSS installation guide describes installation over pipes up to 2⅜ inches outside diameter and explains that the shoe is not a total replacement for removed material.
Do not assume that product addresses a 3-inch opening simply because the framing is 2×6. Its dimensions, installation requirements, and approved application must match the condition. Where an engineered design is required by the evaluation report, that design must also address the actual field condition.
When damage went beyond the prescriptive code limits, we required the proposed repair to be reviewed and approved by the design professional before accepting it at inspection.
A Nail Plate Does Not Establish Structural Repair
A protective nail plate and a structural stud shoe serve different purposes.
Simpson’s training material distinguishes structural repair from protection of piping and notes that some conditions may need both a stud shoe and a nail stop.
Seeing metal over a hole or notch is not enough to approve the framing. Identify the product and what it is intended to do.
This article addresses the structural stud evaluation. Requirements protecting wiring or piping from fasteners are a separate check.
How to Evaluate Drilled or Notched Studs Before Inspection
First determine whether the existing hole or notch meets R602.6. If it does, this section does not require a stud shoe merely because wood was removed.
If a bored hole triggers the doubling provision, check the diameter, doubling, successive-stud limitation, edge clearance, and notch location.
If the condition exceeds the prescriptive limits, identify the proposed correction and its supporting documentation. For an SS/HSS shoe evaluated under ESR-2608, that includes the report’s engineered-design condition where code maximums are exceeded, along with the applicable product and installation requirements.
The question is not simply whether someone added reinforcement. It is whether the completed condition satisfies the governing provision or the approved repair design.
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