DUC-BLOC™ REGISTER SEALING PRODUCTS

Duc-Blocs™ were developed from years of experience performing duct leakage tests. They were perfected while training hundreds of other folks how to perform duct leakage tests.

If you are sealing registers the old fashioned way, up on a ladder with masking tape, just wait until you try Duc-Blocs!

Duc-Blocs are hand built with pride right here in our wood shop in Elk Grove, CA.  We use renewable, recyclable, engineered wood products, such as laminated plywood bottoms and finger-joint rails.  As with any wood product, there may be some minor imperfections.  We like to think of those as “character”.  Even so, Duc-Blocs work great and give you a very professional look.  Some folks have even painted their company logos on them.  Great idea!

Watch The Videos

Part 1 of 3 – Introducing Duc-Bloc (2:22)

Part 2 of 3 – Duc-Bloc Features (2:42)

Part 3 of 3 – How to Use Duc-Blocs (2:54)

Complete Sets Available In Two Sizes 

Duc-Blocs sets come in two sizes:  Basic and Deluxe


The Basic Set includes 10 small pans, 2 large pans and 1 small return pan.

That’s enough to seal 12 supply registers, which is adequate for most residential systems.

The Deluxe Set includes everything in the Basic Set and comes with an additional 6 small pans and 6 regular poles.

  • The small pans are 12” x 18” and easily fit over an extra large 8×14 register.
  • The large pans are 18” x 24” and fit over 14”x14” registers, or larger.

Both sets come with enough poles so that there is 1 pole for each pan, plus 2 poles for the return pan.

They can even be used on high sidewall registers as long as the pole can get about a 45 degree angle and can be braced up against something.

Zip-wall poles can be set on top of beds, low walls, stairs and other obstacles that would certainly make using a ladder difficult.  They also come with rubber non-skid plates that allow you to brace the poles on top of even the most delicate furniture surfaces.

Advantages over the Competition

The main advantage of Duc-Blocs over other register sealing devices on the market is that Duc-Blocs  are braced against the floor and push up against the ceiling, rather than pulling on the register.  Some registers are only held on by a couple screws going into sheet rock.  That’s not much to support the weight and pull of the device, plus the 25 pascals of pressure being exerted on it.

The Return Pan

Most Duc-Bloc sets comes with a small return pan.  This simple little pan was actually an accidental discovery.  It was originally just a cover that sat on top of the stack so that you could put a strap around it.  Now it is one of the most popular items in the kit.  It easily supports the weight of the connector flange and duct so you can tape around it.  Also, be sure to check out the large return pan, below, that seals around register grilles up to 20"x30" with no tape.  Be sure to watch the video.

The photo to the right shows a house that had two returns located in the wall about ten feet above a stair landing. The Duc-Bloc return pan and two Zip-Wall poles held the flex duct like a champ.  This would have been extremely difficult to do without Duc-Blocs.

A Note About Shipping Costs

Shipping is crazy expensive due to the size of the items we sell (except the book, of course).  If we charged the full cost of packaging and shipping, most people would abort the sale at the checkout.  We only use UPS Ground and we only charge a nominal flat fee to help cover the cost of packaging and shipping.  If you can arrange to pick up your item in Elk Grove, just let us know and we will gladly refund the shipping fee back to you.  If you have any questions about shipping costs, please do not hesitate to contact us.