Firestop Putty


For more than 25 years, STI has been creating solutions to help the construction industry provide better firestopping technology. Discount Low Voltage carries a huge selection of firestop putty tubes, sausages, pails and outlet boxes, so you can find exactly the product you need for your job. You will discover a wide range of sizes to let you tackle anything from a small retrofit to major new construction.

By expanding when exposed to high temperatures or flames, these products can prevent the spread of deadly toxic gases, smoke and fire. Easy to apply, often without tools, these products are a must for safer occupancy.


From small to medium openings through common constructions to single or multiple power, voice and data cables and trays as well as single-gang and multi-gang metallic boxes, these products can promote fire safety in a variety of environments. Choose from firestop putty sticks in a wide range of sizes. We also have intumescent and endothermic sealants in sausages and sticks.

For bigger jobs, check out our intumescent and endothermic sealants in 2-gallon, 4.5-gallon or 5-gallon pails. Our putty pads and electrical box inserts make it fast and simple to boost fire safety in electrical boxes with no tools required and fast, easy installation.

Check out our selection of other firestop supplies 
In stock items ship same day if ordered by 2 PM PT.


Many of these products require no tools for installation, making them quick, easy and inexpensive to work with. A big range of sizes is available, allowing you to select the size that’s appropriate for your job and buy no more than you need. Qualifying orders are eligible for free shipping, and orders shipped outside California pay no sales tax.


Check out our brief videos on the individual product pages. They will give you valuable information about the uses and benefits of each product. Spec sheets are available on the products’ pages to give you complete technical information.

If you have questions about what’s right for your job, call us toll-free during normal business hours or send us an email. We’ll help you find the right stuff.