If you are looking for a pet door, there are some very important elements to consider...

For one, considering your dog is going to open the dog door with their face, you owe it to your pet to choose a doggy door that has a flexible flap!

However, the problem with flexible flaps is that they shrink in the cold. This unfortunately means that when it's coldest and you need your dog door to seal at its best, it will actually seal at its worse.

This is what separates the Endura Flap from the rest.

The Endura Flap was designed specifically to address this issue. The solution to having a truly 4­-season, flexible pet door was to incorporate a unique, patented system of magnets that cover all the edges of the pet door. Essentially, the Endura flap starts undersized, but then grows with magnets around its accordion-like bellows to seal regardless of how cold it is outside.

What makes a great pet door?

It's The Flap!

Yes, the design of the frame matters and the interaction between the flap and the frame matters. But if you haven't got a great flap to put in that frame, you can't possibly have a great pet door.

Patio Pacific has specialized in the design of dog doors and cat doors for over 35 years. During that time, they have handled every pet door design imaginable. While many of these have been excellent in one respect or another, none has ever combined all the best features into one product.

Check out our entire line of Patio Pacific and Endura Flap Products.

To be considered perfect, a pet door must (click on links to learn more):

No Pet Door On The Market Has Ever Met This Standard Until Now...

By the way, you may have noticed the green badge on all of the Endura Flap pet door images. That's the Fancy Publications Editors' Choice Award for Innovation and Creativity. No other pet door on the market today has received that award!



Flexibility is Vital for Pet Door Safety

The first design requirement of the Endura Dog Door Flap was that it be flexible.

Though the chance of injury, especially pinching, is small in a rigid flap pet door, it is nevertheless real. Over our 40 years in business, Patio Pacific has encountered injury in all types of rigid flap pet doors. Some of these injuries have been serious.

The Endura Flap™ is soft, flexible and safe.

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Detail of Bellows Showing Magnet Strips Down the Side

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Dual Pane Insulated with Heat Transfer Barriers


Insulation is not as important as a good seal. For example, the best insulating windows available aren't much help if you leave them open 1/2"!

After achieving a good seal, however, insulation is very important. A single-walled flap is not satisfactory for the same reason that single-pane glass is not: It just doesn't insulate very well. While single-pane glass is completely replaced these days by dual-pane glass, most pet doors sold on the market today provide no more than a 1/ 8" thickness of vinyl between the living area of the home and the outside weather.

The Endura Flap™ consists of a sealed unit that is slightly thicker than a dual-pane glass unit and provides comparable insulation qualities.

Heat Transfer Barriers

Heat transfer across an air space in a sealed unit is caused by air currents moving within the space. These currents are caused by the continuous heating and cooling of the air inside the unit.

The Endura Flap™ is divided by horizontal barriers which serve to reduce the effect of these air currents.

A trade Off - Patio Pacific could have filled the flap interior with insulation for better insulation performance. However, it wasn't done for the same reason that dual pane windows aren't filled with insulation: It's better if you to see through.

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UV Retardant Prevents Cracking and Wrinkling in the Sun

UV Resistance

The suns rays are very harsh and will produce a yellowing effect on vinyl flaps. Some of these flaps are heavily tinted to prevent this yellowing from showing.

Besides yellowing, vinyl is weakened by prolonged exposure to ultra-violet.

The Endura Flap™ material is specially treated with a powerful UV retardant

And it's Not made from vinyl.

In intense test chamber exposure equivalent to 2 years of Florida sunlight, no yellowing or degradation of the Endura Flap material occurred.

At the same time the Endura material was tested, vinyl flap samples from every leading pet door manufacturer were also tested. In each case, there was significant yellowing, crackling and degradation of the material.

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Regular Vinyl Flaps

Anyone who has used a pet door for any length of time has seen that the cost of replacing the flaps can exceed the original cost of the door.

This sad fact is because most pet door flaps in use today consist of a sheet of vinyl fastened rigidly across the top of the frame with screws. As the pet goes through the flap it flexes. Worse, the pet must press upward against that flexed area to get full use of the space.

First the flap will 'potato chip' and begin leaking badly. Eventually, the repeated flexing causes the vinyl to crack and tear in just the same way that repeated flexing of a coat hanger will cause it to break.



The Endura Flap™ Pivots!

If the Endura Flap™ material had to flex, it would fail in time also.

But it doesn't flex!

And that simple design difference allows the Endura flap to be flexible and extremely durable at the same time.

The Endura Flap™ is warranted against failure, except for chewing damage, for 15 years.

By the way, since this illustration was designed, the test machine went over 3 million trials. Same result.

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Vinyl Flaps Perform Poorly and Eventually Fail in the Cold

Every winter vinyl flaps that will become stiff in the cold.

Usually they just don't retain enough flexibility to close properly. Sometimes, they get so stiff they break off as the dog attempts to go through!

There are low temperature vinyls available that retain more flexibility in cold weather. However, they are softer and less durable and will need replacement more often. And they still can't stand really low temperatures!

The Endura Flap™

The Endura Flap™ is not made from vinyl at all.

It is manufactured from a polyolefin-based polymer which remains flexible to -40f!

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Flap Variable Magnet Strength Feature

Great! You've installed your new pet door in the back door. Installation looks good; you were careful to get the step-over height right for your dog. You used a level so everything's straight.

Then the wind picks up a little and the flap blows open! You're freezing, the thermostat has the heater on full blast and you're watching dollar bills fly out that #$%%$# pet door.

Or perhaps after days of patient training you find that your little dog just can't seem to manage to push the flap. Other small dogs have done just fine with that same pet door but, for some reason, yours can't manage it.

Generally, the magnet strength of a pet door flap is what it is and if it's not what you need, well, too bad.

There is a solution

The Endura Flap was designed from the beginning to allow for a high degree of variability in magnet strength at the threshold where it matters the most. Endura Flaps ship with 1 or 2 magnet pairs depending upon size. However, they will accommodate up to 3, 4 or 5 magnet pairs if needed for wind resistance. Further, there is an optional threshold which, by using a thinner head space, increases the magnet strength of the magnets in place by approximately 50%.

Among pet doors intended for residential use, none but the Endura Flap line has been designed with this Variable Magnet Strength feature.

Here's a Video with Just One Idea About How to Exploit This Feature

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Low Aspect Ratios are Bad!

Low Aspect Ratio - A Pervasive Problem

Most pet owners are properly concerned that the pet door opening be an appropriate fit for the dog not only when he's a young, agile guy but when he's toward the end of his life and less agile, possibly arthritic or injured in some way. Understandably, this question can be a hard one to answer.

Many pet door manufacturers have no clue themselves!

They will commonly say something like "cats to 15 lbs" or "dogs to 150 lbs". This is nonsense and the worst kind of disservice to the potential customer trying to make a good decision. It is self-evident, for example, that a standard poodle, tall and slim, will best use a very different pet door from the bulkier and much shorter lab. Every dimension matters: The height and width of the flap and also, just as importantly, the "step-over" dimension.

Here's a method that will lead you to a correct answer

Put the top of the flap opening at your dogs withers (top of his shoulders). Having the top of the flap an inch or so above the withers won't matter much to the dog but will extend the otherwise short life of the typical vinyl flap you're probably working with.

With the top of the flap in the proper position, the bottom should be as low to the floor as you can get it! No "step-over" dimension is too short. Lower is always better.

Any rise dimension taller than 30% of your pets height for most dogs, and less for particularly short-legged or deep-chested dogs, is going to be too high to start with and way too high when he's older, less agile and possibly arthritic or injured.

Then call him through an open doorway set at just the proper width in your judgement (it is somewhat subjective and it's your call) and measure that width. That is the absolute minimum width of the flap you should buy.

If you do this a few times with a few different dogs here's what you'll find

First, the minimum width will turn out to be much more narrow than your "guess-timate". This is an optical illusion that we're all prone to and which results in the sale of bigger than necessary dog doors all the time. The dog or cat just isn't as wide as you think he is (unless you're one of the very few I've met over the years that really can eye-ball an accurate width for a pet. Some people have perfect pitch also. But I don't and you, dear reader, probably don't either. Measure the doorway!)

Next you'll find that when you go shopping for a flap that's at least that width, the height of the flap is going to be much less than you'd like.

Why is this?

Most pet doors for sale today have a relatively low 'aspect ratio'. That is to say, they are not very tall for their width. For example, my 75 lb lab stands 22" at the withers and needs a minimum of a 9 1/2" width. The very commonly found 10:" x 15" sized flap is not very satisfactory because if I mount the top of the opening at 22" (her withers), then the bottom will be 7" off the floor (22"-15").

She's fine with that today at age 11, but she's nearing the end of her life and I want her to enjoy her dog door for as long as possible. The flap she actually has now is the Endura Flap at 10" wide by 19" tall and the rise dimension is 3". Much, much better!

The above example represents the situation most commonly found. Dogs are much more often tall and slim rather than short and wide. But most pet doors (not all) are more appropriate for the short-wide type.

Security Concerns

There's frequently another, less obvious problem with these low aspect ratio flaps and that is security. Especially for dogs around 20-60 lbs--which is a lot of dogs--there is a security issue. A great many dog owners will look a typical 8" x 11" flap and say "width is ok but I need more height". Then they look at a the next size up--frequently 10" x 15"--and see that the height is now ok but the additional width that they don't need has made the pet door large enough for a person to crawl through!!

The Endura Flap #8 is 8" wide by 15" tall. Not wide enough for most people to climb through but tall enough for many dogs that are too tall for the typical 'medium' size.

Pet Door Mounting Height

Aspect Ratio Problems Continued

When you mount a pet door, the top of the flap should be at least as high as the top of the dogs shoulder (the 'withers'). It doesn't do a lot to make it much taller than that (unless you have a typical vinyl flap where more height will prolong the life of the flap).

So a higher aspect ratio flap really means that the bottom of the pet door can be lower to the ground!

This height above the ground dimension is called "step-over" and lower is better other things being equal.

Of course, if you do need more width, you get it by getting a larger size. Chances are, though, if you need a wider door, you'll want an even taller one as well and that's what you get with the Endura Flap™.

Another High Aspect Ratio Benefit

A taller flap is easier to share. It also makes the pet door more accessible to the smaller pet that's sharing with the big guy.

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Wind Resistance and Training

Adjustable Magnets On Both Edges and at Threshold

The worst performance a pet door can have is when it blows open in the wind. Then it's really leaking a lot of air!

The Endura Flap™ pet door has been proven in a wind tunnel to resist blowing open in winds in excess of 50 mph! In the same comparison testing, two of the largest selling pet doors on the market blew open at approximately 20 mph. (One was in the high 'teens', the other in the low 20's).

Nearly all customers have been satisfied with Endura Flap™ wind resistance "out of the box". However, magnet kits are available to further increase wind resistance. Each size will accept up to two additional magnet pairs across the bottom of the flap which increases the magnet strength in that area by 50% to 300% depending upon the size of the flap.

Some users would like the flap to be easier to push open while training. The Endura Flap™ design allows for temporary elimination of magnets on the sides as well as across the bottom.

When these magnets are removed, the Endura Flap™ is extremely easy to push and the floating threshold remains in the low position.

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Flap Clarity

Ideally, the flap should be clear and colorless.

The material used in the Endura Flap™ has many advantages over vinyl but is not quite as clear as vinyl can be.

It is clear enough for safety and good aesthetics, however

Here's a tip When you see those heavily tinted, vinyl flaps in the pet shop: Not only do they look bad; the tinting is so you won't notice the UV yellowing that will begin with exposure to the sun.

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Endura Flap™ is Environmentally Friendly

The Endura Flap™ uses a polyolefin-based polymer (similar to material used in food storage containers) which is a non-toxic material that is recyclable and safe for the environment.

Vinyl (also known as PVC)

Vinyl (also known as PVC) is the most popular material used for flaps in the US today. Every flexible flap pet door currently available in PetSmart, PetCo or any other mass merchandiser is made of vinyl.

Here are some links that will make it clear why PVC was not used for the flaps:

PVC and the Environment

The Dangers of PVC

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Endura Flap™ Assembly Cross Section Bottom and Top

Endura Flaps™ are Superbly Engineered

Our design engineer, in examining a competitor's considerably more expensive product, remarked that it was 'under engineered'.

Choose any pet door on the market today and compare it side-by-side with a pet door based upon the Endura Flap™ Assembly and his meaning will immediately become clear.

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Prevent Air Leakage

This 'leaker' is available in most pet supply stores nationwide!

A closer look.

What kind of performance can you expect from your new pet door?

That's going to depend primarily on the flap in the pet door you buy.

The examples to the right show a very popular 'large' size flap that has been used by two dogs--one about 75 lbs and one about 60--for a period of around 3 years.

The edges of the flap are severely 'potato chipping' and, consequently, let in large amounts of outside air. Here in San Luis Obispo, California, that doesn't matter too much and replacing the flap hasn't been a high priority. (Obviously, cleaning the flap hasn't been either!).

What if you happen to be in a less climate-friendly area?

Some manufacturers include fuzzy weather-strip down the sides of the frame which is an improvement. Unfortunately, the fuzz still passes air freely.

Some will also include an occasional magnet on the side which helps also.

However, our new Endura Flap™ (patented, pat. pending) pet doors are very best solution to this problem:

  • Continuous magnetic contact top to bottom.
  • Unique 'bellows' on both flap edges permit temperature change expansion and contraction without breaking the seal.
  • Pivot rod allows the flap to swing without flexing so the flap material doesn't flex and fail.
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Endura Flap™ Pet Doors Are 100% Designed, Engineered and Manufactured in the US

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