Putty Pads & Electrical Box Protection
Electrical boxes are the most common membrane penetration in fire-rated walls — and code limits how many you can have, how close together, and how they must be protected. These products restore the wall rating: moldable fire-rated putty pads wrap the outside of the box, putty sticks pack irregular openings, and the Metacaulk-exclusive Box Guard and Cover Guard protect from inside the box or behind the cover plate.
Putty pads are the fastest, most familiar method: peel, wrap the box, done — self-adhesive, intumescent, and available in 6×7, 7×7 and 9×9 sizes. Box Guard friction-fits inside the box cavity with no wall-side access needed, and Cover Guard installs invisibly behind the cover plate — ideal for retrofit and finished walls where opening the wall is not an option.
All are UL Classified for use in rated gypsum assemblies. Firestop-USA stocks full cases at distributor pricing with same-day shipping — and if an inspector has flagged boxes on your job, call us and we will match the fix to the citation.
Which one do I need?
Putty Pads & Electrical Box Protection — the lineup
Metacaulk® Fire-Rated Putty Pads & SticksMoldable, non-curing, single component fire-resistant material.View product, specs & TDS →
Metacaulk® Box GuardSingle component, highly intumescent graphite-based insert for inside electrical boxes.View product, specs & TDS →
Metacaulk® Cover GuardSingle component, highly intumescent graphite-based gasket for electrical box cover plates.View product, specs & TDS →Putty Pads & Electrical Box Protection — frequently asked
When are putty pads required on electrical boxes?
Generally when boxes exceed 16 sq in per 100 sq ft of wall, when boxes on opposite sides of a rated wall are within 24 inches horizontally, or whenever the wall listing requires it. Putty pads (or listed box inserts like Box Guard) restore the rating and let you reduce that separation.
What is the difference between Box Guard, Cover Guard and putty pads?
Putty pads wrap the OUTSIDE of the box (needs an open wall). Box Guard is a friction-fit intumescent insert placed INSIDE the box cavity. Cover Guard installs behind the cover plate — invisible and perfect for finished walls. Box Guard and Cover Guard are Metacaulk exclusives with no Hilti/3M/STI equivalent.
Are these UL Classified?
Yes — Metacaulk putty pads, putty sticks, Box Guard and Cover Guard are UL Classified for membrane-penetration protection in fire-rated gypsum wall assemblies. We supply the UL listings for your submittal free.
Need the right UL system?
Send your penetration schedule or a photo — we match the UL Classified system, provide submittal documentation free, and ship same-day from New Jersey at distributor pricing.
More firestop categories: Firestop Sealants · Pipe Collars, Wrap Strips & Sleeves · Cast-In Devices & Cable Pathways · Pillows, Mortar & Composite Sheet · Cable Coating, Foam & Accessories · Hilti / 3M / STI cross-reference