Critical Specifications for Carpet Durability
What could be more exciting than learning about carpet specifications?
Okay, fair enough. But stick with me. If you plan on buying carpet, this is important.
And don’t worry, I’m not going to educate you on how carpet is threaded into the backing. You can find that on another website. No useless details here. This is only the information that impacts how long your carpet will last.
In other words, this report only covers what matter to you as a carpet shopper.
Solving the durability puzzle
Let’s start by making an important clarification…
This article is about the specifications that impact your carpet durability. There are important parts of the durability puzzle that are not specifications. Those can be found on other Carpet Captain pages like this one comparing carpet fiber types and this one on padding.
So the next question is… What specifications are important to carpet durability? Here’s a list…
- Face weight
- Total weight
- Density rating
- Wear rating
- PAR rating
- Twist level
I’ll cover the pros and cons of each specification. You’ll learn how certain specs can be used against you. And I’ll give you ranges that indicate poor, acceptable, and best durability.
Let’s start with the most common carpet specification.
Face weight is the most common specification you’ll find to determine a carpet’s durability. Face weight is the weight (in ounces) per square yard of carpet. This is a good but not perfect measure of “how much” carpet you have.
What do I mean by “how much” carpet you have? Face weight measures how much the fiber/yarn of the carpet weighs. Think of it like weighing t-shirts that are all the same size. The more they weight, the thicker and more durable the t-shirt is going to be. The only difference being durability matters much more in carpet. People aren’t walking on your t-shirts all day.
Earlier I said face weight is a good but not perfect measurement. That’s because it can be misleading.
It doesn’t take into account how “tall” the carpet is. The height of the carpet fibers will increase the face weight, but it doesn’t improve the durability (if anything, it leads to carpet breaking down sooner).
Here’s an example…
Let’s say you’re looking at two carpets. One is named ‘The Durable Carpet’ and one is called ‘The Misleading Carpet.’ You look at the face weight of each. ‘The Misleading Carpet’ has a 40 oz face weight, and ‘The Durable Carpet’ has a 35oz face weight. ‘The Misleading Carpet’ is the more durable carpet right?
And I think you can see where I’m going with this. You look into it more and ‘The Misleading Carpet’ fibers are twice as tall as ‘The Durable Carpet.’ That artificially inflated the face weight of ‘The Misleading Carpet.’ It turns out, ‘The Durable Carpet’ is the denser, more durable carpet. It just had a lower face weight because its strands are shorter.
So let’s get to the ultimate question…
What face weight carpet should I buy?
You want at least a 35 ounce face weight carpet for maximum durability. Depending on other features of your carpet, a lower or higher face weight may be required. Factors that may affect the minimum face weight needed are how often the room is used, the carpet’s twist level, and the carpet’s density.
Guidelines for face weight:
|Durability||Carpet Years||Face Weight|
|Poor||Less than 7||Less than 30 oz|
|Acceptable||7 to 12||30 to 40 oz|
|Best||12+||Over 40 oz|
A carpet’s total weight is the face weight + weight of the backing. Backing is heavy compared to the carpet fiber, so total weights are much higher than face weights. The weight of the back also doesn’t mean much as far as durability. Yes, a heavier backing may be better made, but it’s not accurate enough to judge a carpet.
What total weight carpet should I buy?
Trick question. Total weight is too misleading to give you recommended values.
Captain’s math lesson:
[density rating] = [face weight] *36 / [pile height in inches]
Don’t worry, there won’t be a quiz. The equation isn’t important, but breaking it down reveals a couple important takeaways about density rating. The most important takeaway is density rating eliminates the flaw of face weight: the longer/higher pile the carpet, the lower the density rating.
The second takeaway is density rating is a much higher number than face weight, so face weight and density rating can’t be compared directly. If you want to go through the work, you can convert face weight to density by multiplying the face weight by 36 and then dividing by the pile height. You should be able to find the pile height in the carpet information. If you can’t find it, you can measure it yourself (base of the carpet to the top of the carpet fiber).
What density carpet do I need?
You want a carpet density with a density of 2,900+ for good durability, and I’d be cautious with anything less than 2,500 in moderate traffic rooms. Density is the best specification to determine durability. But remember that there are other factors that impact durability. Depending on these other factors and how much traffic your carpet will get, the density rating you need can vary.
Here are ranges for carpet density:
|Durability||Carpet Years||Density Rating|
|Poor||Less than 7||Less than 2,100|
|Acceptable||7 to 12||2,100 to 3,100|
|Best||12+||Greater than 3,100|
Wear rating/Durability rating
Wear rating is a subjective measure of how long the carpet will last. It’s determined by the carpet manufacturer, and it’s usually a 1-5 rating system. Since the rating is created by the same company selling the carpet, it’s in your best interest to not put too much stock in it.
The problem with the rating is the manufacturer can give a bias toward anything they want to sell. If they have a “new and improved” stain protection that gives them added profits, they’ll likely give carpets with the new stain protection the best grade whether it works well or not.
The most important reason to throw this rating out the window is you can make a better “wear rating” of your own. Your knowledge from this page and our carpet buying guide gives you the best picture of how well a carpet will hold up.
PAR rating is somewhat of a mystery, but I included here because I get questions on it. Most internet sources say it is a rating created by the carpet manufacturer Shaw. I reached out to Shaw, and they stated PAR is not a rating they use. I contacted Mohawk (the only carpets I have seen use a PAR rating), and they were able to give me an explanation. They didn’t go into specifics but said it based on an industry standard test using a mechanical drum (basically beating the carpet with a machine to see how much it wears). I put this is the same category as “density rating” (see above). It gives you some useful information, but there are better ways to determine how durable your carpet is.
Twist level is the number of twists in one-inch strand of carpet. Higher twists result in a more durable carpet. Lower twists can lead to the carpet unraveling. This can make a carpet look old fast.
As an analogy, think of braided hair. Twist the braid once or twice, and it’s going to be loose and fall apart. If it’s tightly twisted, it will hold together throughout the day (I have a feeling I somehow blew my cover that I don’t know much about braiding hair in this last paragraph, but hopefully the analogy still made sense).
Many shoppers overlook twist level. It may not be as important as the density rating, but it still can have a major impact on how long your carpet lasts. No matter how high a carpet’s face weight, it will look terrible in a few years if it has a poor twist level.
You should find the twist level listed in the carpet information. If it isn’t listed, you can calculate it. Here’s how:
Twist level = [# of twists] / [inches of carpet]
Here’s how to use this equation… Start by counting the number of twists in a strand of the carpet. Let’s say you count 3 twists. Next, measure the height of the strand of carpet. Let’s say it measures to be half an inch. Your equation is 3 divided by 0.5, which equals a twist level of 6.
How many twists do I need in my carpet?
Look for carpet with a twist level of 5 or more. The higher the twist level, the better. Four or fewer twists can lead to poor performance. Sometimes the twist level won’t be listed. If it’s a frieze carpet, you can assume it has a high twist level. If it’s not frieze, you can try to calculate the twist level (see the equation above).
Captain’s parting words!
That covers the important specifications for carpet durability. If I had to pick only two of these to go by, I’d choose the density rating and twist level. If you can’t find or calculate the density rating, face weight is a good alternative.
Wear ratings/durability ratings are too biased to use in your final decisions. Their only value is helping with what carpets are not durable. This won’t help you decide what carpet to buy, but it can help you quickly eliminate less durable carpets. In an example for high-traffic rooms, you could decide you won’t consider carpets with a wear rating of 3 or less.
As for total weight, ignore it. It’s a misleading measurement.
So where do you find these specifications?
Any important specification should be easily available in the in-store carpet materials. The keyword is should. Some carpet shoppers tell me the store information wasn’t helpful. If they don’t want to give it to you, you can calculate some of the measurements yourself or consider a different store.
You have a right to know how well made your multi-thousand dollar flooring investment is. You’re on the right path. Make sure to you cover the rest of the important details in our complete guide on how to buy carpet.