How Multi-Fit Chimney Caps Can Serve 96% of Your Retail Customers

From left to right: a small, medium, and large Duro-Shield cap made by HY-C against a white background

Chimney flues come in all shapes and sizes. Almost too many, actually — from a 5” x 9” flue to a 30” x 30” flue and everything in between, there are over two dozen sizes of flue pipes in chimneys across America (and that’s not even counting round flues).

If you’re a retailer, it can feel like an impossible task to carry the right chimney caps to serve your customers. You can only guess what cap size they’ll need, and chimney caps are far too bulky to stock all (or even some) of the available sizes on your already-limited retail shelf space.

At HY-C, we’ve been manufacturing chimney caps for over 75 years, and we’re very familiar with this problem. We’ve heard about it from dozens of our sales partners. That’s why we invented the Duro-Shield chimney cap family, a line of just 3 multi-fit chimney caps that cover over 96% of chimney flues.

How can that possibly work? How much shelf space do these caps take up? And why does HY-C still manufacture other caps if these three fit almost every flue? What’s the catch?

In this guide, we’ll answer those questions and more. By the time you’re finished here, you’ll understand the range of chimney flue sizes that exist and how the Duro-Shields were designed to fit them. You’ll also understand how much shelf space Duro-Shields take up (relative to standard chimney caps) and the potential cons of carrying them in your store.

A Quick Guide to Chimney Cap Sizes

A stainless steel HY-C chimney cap installed on a chimney flue against a white background

Chimney caps are designed to cover one of two chimney flue configurations:

  • Single-flue chimneys (with only one flue pipe protruding from the chimney
  • Multi-flue chimneys (with two or more flue pipes protruding from the chimney)

At HY-C, over 96% of the chimney caps we manufacture are single-flue caps. The other 3% are made for multi-flue chimneys. As a retailer, it’s virtually guaranteed that your customers will come into your store shopping for a single-flue chimney cap.

So, with that in mind, what single-flue cap sizes are there?

Well, we make our caps to fit specific flue pipe sizes. Flues are measured by their length and width, and chimney caps are measured similarly. Here’s a list of all the flue sizes we make caps for, and how many of each cap size we make (as a percentage of the total caps we manufacture):

Flue Tile SizesPercentage of TotalFlue Tile SizesPercentage
13″ x 13″31.84%13″ x 17″0.10%
9″ x 9″31.37%5″ x 9″0.10%
9″ x 13″27.21%17″ x 21″0.08%
13″ x 18″5.30%30″ x 30″0.07%
9″ x 18″1.01%17″ x 17″0.06%
18″ x 18″0.71%8″ x 17″0.04%
13″ x 20″0.42%21″ x 21″0.04%
12″ x 16″0.36%9″ x 21″0.04%
12″ x 12″0.30%10″ x 17″0.03%
15″ x 15″0.28%13″ x 21″0.02%
20″ x 20″0.18%8″ x 20″0.02%
11″ x 11″0.17%8″ x 13″> 0.01%
16″ x 16″0.13%24″ x 24″> 0.01%
13″ x 16″0.12%16″ x 20″> 0.01%

As you can tell, some cap sizes are more common than others. For instance, 13” x 13” and 9” x 9” chimney caps combine to account for over 63% of all the caps we manufacture. By contrast, we don’t make many 8” x 13”, 24” x 24”, or 16” x 20” caps.

What’s more interesting to retailers, though, is that of the 28 flue sizes listed in this table, our three Duro-Shield multi-fit caps cover 23 of them.

Duro-Shield Multi-Fit Chimney Caps

All the components of a HY-C Duro-Shield chimney cap, including the hood, the mesh, the attachment braces, and the hardware laid out on a white background

So, how are multi-fit chimney caps so versatile when it comes to size?

Unlike more traditional chimney caps that come with their base, hood, and mesh screens all welded together, Duro-Shield multi-fit caps are packaged knocked-down. They come with a hood, four pieces of metal mesh, four mounting brackets, and hardware, and they need to be assembled by the installer.

While it does require a little more work, the fact that multi-fit caps require assembly is exactly what makes them so versatile: you can assemble yours to fit almost any flue tile size you need.

Our Duro-Shield caps come in three sizes — small, medium, and large — each with a slightly bigger hood and longer mesh screens to fit bigger flues. Here’s that same chart from above, but this time, with the multi-fit chimney cap size applicable to each flue tile size:

Flue TileMulti-Fit Cap SizeFlue TileMulti-Fit Cap Size
13″ x 13″Medium13″ x 17″Medium
9″ x 9″Small5″ x 9″Small
9″ x 13″Small17″ x 21″n/a
13″ x 18″Medium30″ x 30″n/a
9″ x 18″Medium17″ x 17″Large
18″ x 18″Large8″ x 17″Small or Medium
13″ x 20″Large21″ x 21″n/a
12″ x 16″Medium9″ x 21″Medium
12″ x 12″Small or Medium10″ x 17″Medium
15″ x 15″Medium13″ x 21″Large
20″ x 20″n/a8″ x 20″Medium
11″ x 11″Small8″ x 13″Small
16″ x 16″Medium24″ x 24″n/a
13″ x 16″Medium16″ x 20″Large

There’s a multi-fit chimney cap available for 99.63% of the single-flue chimney caps we manufacture. Even with multi-flue caps thrown in, 96.7% of the chimney caps we make can be covered by one of the three multi-fit caps instead.

Shelf Space

Chimney caps take up a lot of space. There’s just no getting around it. They take up space in warehouses, on trucks, and on retail shelves. But they don’t all necessarily take up the same amount of space.

A Duro-Shield chimney cap in its box next to a 9" x 9" Draft King black galvanized chimney cap in its box, both sitting on a carpeted floor against a white wall with a red mop guard

On the left is a Duro-Shield multi-fit chimney cap in its packaging. On the right is a standard 9” x 9” chimney cap in its packaging.

The 9” x 9” cap’s box measures 9” x 15.25” x 15.25”. That’s about 2,100 cubic inches, or 1.20 cubic feet.

The Duro-Shield, while admittedly in a less eye-catching box, measures about 2.25” x 20” x 21”. That’s around 945 cubic inches, or just 0.55 cubic feet.

To put that in perspective, a 4-foot retail shelf can fit about 21 Duro-Shield caps stacked vertically, side to side. The same shelf can accommodate around ten 9” x 9” caps (two stacked rows, each containing 5 caps) — less than half the amount of caps as the Duro-Shield.

What’s the Catch?

At this point, you may be thinking, “So you’re telling me there are three economical, space-saving chimney cap SKUs I can stock that will serve virtually every customer who walks in my store. That sounds too good to be true. What aren’t you telling me?”

And that’s a fair point. After all, multi-fit chimney caps aren’t without their caveats.

First of all, all of these Duro-Shield multi-fit caps are made of aluminum, arguably the weakest chimney cap material. One of the primary duties of a chimney cap is to keep out animals, and most common critters can chew right through the mesh of an aluminum cap. The cap will act as a deterrent, but nuisance wildlife may figure out how to bypass it after a while.

Aluminum caps like these without a tight, tailor-made fit may be more susceptible to falling off due to wind and weather. Don’t get us wrong, they do fit securely. But in a head-to-head battle with a more traditional cap, the multi-fit cap would likely be the first to become dislodged over the course of regular, seasonal use.

A Duro-Shield multi-fit chimney cap installed on a round chimney flue against a white background

It’s also important to note that these caps are only available in one color: untreated aluminum (which appears silver). Traditional caps offer a few more options to fit the aesthetics of your customers’ homes, like black galvanized steel or even copper.

Finally, Duro-Shield multi-fit caps need to be assembled after they’re purchased (while other caps come pre-built). Again, this is what allows them to fit multiple flue tile sizes in the first place, but the assembly may prove difficult for some customers.

Ultimately, these caveats are just that — caveats. Things to be aware of. You know your customers best, and you know what kind of products they prefer. And if they prefer a simple, no-frills, one-size-fits-most solution that’s easy to use, they can’t go wrong with a multi-fit cap.

Should You Stock Multi-Fit Chimney Caps?

Though it may not seem like it at first, the subject of chimney caps is a lofty one. And as a retail buyer, you’re asked to know as much about them as possible so that you can make the right decisions as to what to stock in your store.

So, are multi-fit chimney caps right for you and your business?

If you run a big box retail store and you have the shelf space to dedicate to more robust, traditional chimney caps, that may be the better way to go. They tend to last longer, and customers will appreciate the versatility of your offering.

But if you’re tight on space and you’re looking for a cost-effective solution that works for just about anyone who walks in your store, that’s exactly what multi-fit chimney caps are made for. When every inch of space counts, these caps maximize your dollars per square inch.

To find out how to get multi-fit caps on your store shelves, get in touch with one of our account managers. They’ll work with you from your initial consultation all the way through to placing a purchasing order (and beyond!) to make sure you get exactly what you need on your shelves for your customers.

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