“Over Air Barrier” Electrical Light Mounting Block

Over Air Barrier Electrical Light Mounting Block – Eliminate the Hole, Eliminate the Risk

What’s the best way to stop moisture intrusion behind exterior lights and plugs? Simple: eliminate the hole altogether.

Traditionally, exterior electrical boxes are mounted by cutting a large opening through the sheathing to fasten them to a stud. However, this process creates a major vulnerability in the air/moisture barrier—violating NBC standards and putting your home at risk. Professionals have tried to seal these gaps with spray foam, flashing tape, and other products, but these methods are costly, labor-intensive, and often installed improperly.

The Smarter, Cleaner Solution

The Over Air Barrier (OAB) Electrical Light Mounting Block solves this problem at its source. Instead of cutting a large opening, the box mounts entirely outside the air/moisture barrier. The only required penetration is a 3/4” hole for the wire, which can be easily sealed with caulking—no spray foam or tape needed.

This design ensures a better seal, faster installation, and fewer long-term issues related to moisture or code violations.

More Placement Flexibility

Unlike traditional in-wall boxes that must be mounted to a stud, the OAB box attaches directly to the sheathing. This gives you greater flexibility in light fixture or outlet placement, allowing for precise positioning without compromising the integrity of your wall system.

Features and Benefits:

• Keeps the electrical box outside the air/moisture barrier

• Requires only a 3/4” wire hole, fully sealable with caulk

• Saves time, money, and reduces installation errors

• Installs directly to sheathing—no stud required

• Ideal for exterior lights and plugs

• TL tested to CSA/UL for wet locations

• Optional Rain Screen Spacer available for added airflow

• Meets NBC standards and reduces future risk

Product Specifications:

• Overall Dimensions: 7 1/2” x 8 1/2”

• Base Dimensions: 5 1/2” x 6 1/2”

• Compatible Sheathing Depths: 5/8”, 3/4”, 1”, and 1¼” (1.59cm to 3.18cm)

• Electrical Base: CSA/UL equivalent to 18 cubic inches

• Quantity: 12 per carton

• Available with Rain Screen Spacer

At HandrailCovers.com, we design smarter siding accessories that save time, prevent problems, and deliver professional-grade results. Over Air Barrier Mounting Blocks are the cleanest, most code-compliant way to mount exterior plugs and lights.

Additionally, the “THIRD WAVE” accessories are designed to accommodate various thickness depths, including 5/8”, ¾”, 1”, and 1¼” (1.59 cm to 3.18 cm). These accessories offer even more customization options, making them a versatile choice for a variety of projects.

Add to cart now and make moisture intrusion a problem of the past.