SpecSeal® EP Powershield™ electrical box inserts are one-component intumescent pads designed for fire protection in electrical switch and outlet boxes. These easy-install inserts expand 24 times their original size when exposed to flames, maintaining fire-resistance ratings in wall assemblies where electrical boxes compromise structural integrity.

Key Features & Benefits

24x expansion ratio – rapid intumescent growth seals fire and smoke passages
No tools required – simple adhesive installation with no mess or residue
2-hour fire rating – UL certified to UL263 (ASTM E119, NFPA 251) standards
STC 64 acoustic rating – superior sound transmission control
Water resistant – no soluble or hygroscopic ingredients for long-term reliability
Non-conductive – safe for installation inside energized electrical boxes
Low profile design – 1/8″ thickness maximizes usable box interior space
Retrofit capability – installs in existing walls without box removal

Applications & Code Requirements

Required Applications

Box spacing – when horizontal separation between boxes is less than 24″ (610mm)
Large boxes – when individual box size exceeds 16 in² (103 cm²)
Opening density – when total openings exceed 100 in² per 100 ft² of wall area
Fire-rated assemblies – maintains wall assembly fire ratings per UL Category CLIV

Installation Types

New construction – install before or after wallboard installation
Retrofit projects – upgrade existing boxes to meet current fire codes
Commercial buildings – office, healthcare, educational facility compliance
Residential construction – multi-family and high-rise fire protection

Product Models & Specifications

Bulk Packaging Options

EP44-Bulk – 600 units for large projects
EP45-Bulk – 450 units for commercial installations

Physical Properties

Color – Red for easy identification during inspection
Expansion temperature – Begins at 350°F (177°C)
Expansion range – 350°F to greater than 1,000°F (538°C)
Service temperature – Less than 130°F (54°C) continuous
Shelf life – Unlimited with proper storage

Performance Standards & Testing

Fire Resistance Testing

UL263 certification – meets ASTM E119 and NFPA 251 standards
Category CLIV – Wall Opening Protective Material classification
2-hour rating – proven performance in gypsum wallboard assemblies
Back-to-back installation – tested with reduced spacing on steel studs

Acoustic Performance

STC 64 rating – superior sound transmission control per ASTM E90-04
Construction compatibility – maintains or improves wall acoustic properties
Low profile – minimal impact on box interior space utilization

Installation Advantages

Traditional vs. SpecSeal® EP Powershield™ System