Unique Core Bore Seal

Core Bore Firestop System

Product Sizes

Unique Core Bore Seal. Bottom view.

Core Bore Seal Firestop System

Top View


The UNIQUE Core Bore Firestop System is a revolutionary way to cover, firestop, water and smoke-seal abandoned (empty) core holes in fire-rated concrete slabs and walls. Drop it in the top side of the hole and forget it. And it is completely removable!


Core Bore Firestop System

Use our UNIQUE Core Bore Firestop System to cover and firestop empty core holes in concrete slabs or walls during construction and post-construction. These core holes are often abandoned when firestop sleeves or conduits in a concrete firewall or fire-rated barrier are removed. Empty holes can be dangerous because in case of a fire, the firewall will fail to protect the occupants as expected.

New Sizes! Now available in 1.5″, 2.0″, 2.5″, 3.0″, 3.5″, 4.0″, 4.5″, 5.0″, and 5.5″ to better fit your core hole’s diameter. Because the Core Bore Firestop System must fit inside the core hole, these system sizes are based on the core hole’s minimum diameter. Be sure to specify the core bore seal minimum diameter when ordering.

Easy to Install with NO TOOLS! For questions about choosing the correct size, installation or anything else, call our friendly expert Customer Service Support at 251-960-5018.

Our heavy-duty Core Bore Firestop System saves installation time and money while meeting all building codes. It is made of high-grade plate steel and a firestop muffin (plug). It comes with everything needed to install it except the firestop caulk. The Core Bore Seal is inserted into the hole and a bead of caulk under the top plate will smoke seal the Core Bore to the slab or wall. Our Core Bore Firestop System provides 100% firestop and smoke protection. The top plate can be covered by carpet. System may be easily removed when the core hole is again needed and does not require access to the floor below.

Guaranteed AHJ acceptance. Your System is approved when the Inspector says it is! Now we offer two ways to submit your request form to the AHJ:

  1. Download the original AHJ Request Form for pre-approval of your firestopping system. Use it for submission to the Inspector so he/she may pre-approve your proposed System.
  2. Use our convenient new form to email your proposed firestopping system specs to your AHJ- (Authority Having Jurisdiction)- for preapproval. See the new form on the ‘Inspector Preapproval’ tab.

Order Unique Firestop Caulk here. It’s the perfect general-purpose firestopping sealant for all your firestop installation needs.

UL Classified with STI intumescent plugs.

Installation Procedure

Select proper size Core Bore Seal by measuring the diameter of the empty core to be firestopped and sealed. Core Bore Seals come in 1/2 inch diameter increments for concrete slabs measuring between 3″ and 12″ thick. If you have any questions about proper sizing, please call our friendly expert Customer Service Support at 251-960-5018.

Clean the top edge of the core hole with a clean damp cloth to remove all dirt and debris so a good seal can be made.

Apply a 3/8 to 1/2 inch bead of intumescent fire stop caulk to the floor/wall where the Core Bore Seal will make contact.

Be sure the STOP sign is up and carefully place the Core Bore Seal in the core hole. The nut holds the system together and is not removed.  NO TOOLS REQUIRED. Step on it. Wipe away excess caulk. ALL DONE!


Access the SDS for the fire-rated plug (made by STI) here:

Certificate of Compliance

Access the Certificate of Compliance for this product. Plug is made by STI:

Certificate of Conformance

Access the Certificate of Conformance for this product.Plug is made by STI:

Product Data Sheet

Access the Product Data Sheet for the Intumescent Plug (made by STI):

Engineering Judgement


Inspector Preapproval

Use this convenient form to send your proposed firestopping system specs to your AHJ- (Authority Having Jurisdiction)- for preapproval. Your System is approved when the Inspector says it is! Note that you will use one AHJ form for each UNIQUE firestop product you specify.