Congratulations! You’ve Found the SureSeal Solution!

The perfect solution for your sealing application! SureSeal brand sealant seals like a closed cell foam, but expands and contracts like an open cell foam. It won’t take a significant compression set. It’s a snap to apply, and it stays in place without staples or fasteners, even in cold, damp weather. It’s not messy to use like caulk. There is virtually no cleanup! Just throw away the paper backing. It has a shelf life measured in years, not months. It’s economical. But most of all, it’s EASY and it WORKS!

SureSeal has been around for over 25 years, but only recently has word begun to really get out about its amazing sealing properties. Laboratory and real world testing has shown that it will STOP air infiltration through a joint even under pressures equivalent to 100+ mph winds. It will also STOP water migration through a joint even under pressures equivalent to submersion in over 6 feet of water.

About Us

Denarco, Inc., the maker of SureSeal, was founded over 25 years ago as a response to the growing recognition that control of air infiltration in a structure was the most important means to improve energy efficiency. We are a family owned company, founded by Dennis Harr and passed on to his son Andrew in 2013. Although Dennis is no longer with us, his vision lives on as Denarco expands into new markets with its signature SureSeal foam tape.

Denarco is committed to the concept of sustainability…not as a buzzword, but as a philosophy that informs every decision we make. Our product improves the sustainability of our planet’s energy resources. It also improves the sustainability of the cash in your wallet. As a family company, we run Denarco in a way that ensures we will be around for the long haul…through partnerships with our customers, working together to find better solutions to existing problems.

Who Can Use Sureseal


The ultimate responsibility for the energy efficiency of a structure rests with you. Click here to find out the technical specs, lab tests, and research that prove that SureSeal is the right solution for your project.

Contractors / Builders

You’re already using SOMETHING to seal the structures you build. If you’re a drywall contractor, insulation contractor, or general contractor, click here to find out the best uses for SureSeal, and why it’s the right choice for you.


Interested in bringing better sealing solutions to your network of contractors?  Click here to find out more about becoming a SureSeal distributor.


Air Tight Drywall

Low-density, closed-cell foams such as PVC and ethyl foam take an absolute “compression set.” Once compressed, they remain fully, or almost fully, compressed. If a joint opens up over time, the seal is lost. And closed-cell materials can only be compressed about 50 percent before cell walls begin to rupture… Read more

Sill Seal

If you’ve made it to this page, it’s because you know something’s not right with most sill seal products. While most products are relatively easy to use and provide an adequate capillary break, the SEAL part of the equation is severely lacking. … Read More

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Our Advantages

Being energy-conscious isn’t just about producing clean energy, it’s about making our residences as energy-efficient as possible. SureSeal reduces air infiltration and lowers heating and cooling bills. Click below for additional info on air sealing your home.

Our competitors can’t hold a candle to us! SureSeal outperforms every alternative sealant. Click below to see why we’re superior to caulk, butyl, open- or closed-cell foam, and spray foam.