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Alan Fletcher - Carpet Expert / Consumer Advocate - Retired after 30 years, do not sell or install carpet.



Carpet Specifications Explained



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Understanding Carpet Specifications is the ONLY sure-fire way for you to know if the carpet you select is able to tolerate your level of foot-traffic. 


Knowing a little bit about carpet specifications also helps you determine how long your new carpet will last and retain its like-new appearance.


Many homeowners select a grade of carpet not designed to meet their needs and goals. They make their choice based on cost rather than quality. It's hard to tell if one carpet is more durable than another just by looking at it or feeling how soft it is. 


All carpets look and feel great when new. The only way to tell the difference in quality is to understand carpet specifications.





Carpet Prices Are Going Up!


Padding and installation prices are going up significantly too. When you walk into a carpet store, the price you see posted on the carpet sample is for the carpet only. It does not include padding or installation. It also does not include any extra products or services your job might require. 


So if the carpet only price is $3.49 per square foot, your final cost could be closer to $5.00 per square foot (or more) after adding in the cost of padding and installation. 


"When you sacrifice quality you also reduce durability and the lifespan of your carpet."



Dean and Paula are a couple in their 30's with 2 young children and two large dogs. They thought they could replace their carpet in the living room and three bedrooms for about $2500. They needed about 900 square yards (100 sq yards) and they expected their new carpet would last at least 10 years. 


When they looked at carpet prices at the local box store, they were shocked to see what $2500 would afford. To make it work within their budget they ended up choosing a lower grade of carpet made from polyester. 


Then two years later they discovered their new carpet was wearing out way faster than they expected. It was matting down in all the main walkways and it wasn't looking like-new anymore.


Dean and Paula really needed to spend at least $4500 to get a grade of carpet designed to meet their needs, goals and lifestyle. The carpet they selected was not designed to tolerate their moderate level of foot traffic.




Carpet Durability Guide Chart


Carpet Durability Guide Chart If you want to make a wise carpet selection and be sure to get your full monies worth, you need to know what carpet grade or quality level of carpet you need to buy for your home. 


I created a simple test to help you determine your level of foot-traffic you have in your home. It just takes a minute or two to take my free Carpet Foot-Traffic Test


Then use my Carpet Durability Guide Chart to rate any carpet you are considering.








How to Find Carpet Specifications

Sometimes locating all the carpet specifications you need to help you make wise and informed carpet-buying choices can be difficult, if not nearly impossible, depending on where you shop for carpet. 


Some carpet manufacturers are reluctant to freely provide carpet specifications to their dealers and their customers. Some carpet retailers are also reluctant to provide carpet specifications to their customers. 



The Carpet "Specification" Label

On the back of almost every retail Carpet Sample there should be a manufacturer's label that shows the... 


This is must-have information that every homeowner needs to help determine how durable the carpet is, to help determine its value; and determine whether or not it would be a suitable choice to meet your needs, goals and lifestyle. 



Here is a Carpet Warranty Label


carpet sample specifications labelThere should also be other information shown on the warranty label.

  • Anti-stain treatments that may have been applied (Scotchgard)

  • Manufacturer's brand name (Shaw, Mohawk, Dream Weaver)

  • Carpet style name (e.g., Enchanted Evening II)

  • Color name or color number (Emerald Green or EG-124)




Carpet Wear Warranty Label

You should also find the warranty wear limits listed on the back of the carpet sample. Learn more about Carpet Warranties






Carpet Specifications Hard To Find?


1. What is Carpet Pile Height?

If you want your carpet to last longer, I recommend a Carpet Pile Height of less the 3/4". On stairs, I recommend a Carpet Pile Height of 1/2" or less and a Carpet Padding Thickness of 7/16" or less and a Pile Density Rating of at least 8-pounds. Learn more about How to choose the correct Carpet Padding


The Pile Height measurement is not always shown on the carpet sample, however all you need is a tape measure. Don't include the carpet backing, just measure the soft fibers from the backing up. 


Convert the measurement into a decimal for calculating purposes. Example= One half inch (1/2") is equal to (.5) decimal. See Conversion Chart Below.


I generally recommend a pile height of 3/4" (0.75) or less to help reduce the chance of matting and crushing of the pile over time. Why? A shorter Pile-Height makes for a much more durable carpet, it makes the carpet much easier to clean and makes the carpet more stain resistant and less prone to matting and crushing of the pile.


For example, we all know that Commercial Grade Carpets usually have a very short pile-height and have a dense pile. They can tolerate heavy foot traffic for decades and are easily cleaned time and time again. This is the recipe for success commonly used in offices, airports, casinos and banks all across America.





Looped Berber Carpet Styles

Looped Berber Carpet


Looped Berber styles are best when the loops are smaller and tightly packed together. Large loops tend to fall over and look worn out very quickly. 


Inexpensive looped Berber styles tend to have larger loops and are typically made from Olefin, which a durable fiber but hard to keep clean fiber (it tends to attract dirt). Better grades of looped Berber styles are typically made from Nylon and have smaller loops and are much more durable and easier to keep clean. 



Nylon Berber styles are often twice as costly as a Berber made from Olefin, however a Nylon Berber will easily last a lot longer and retain its like-new appearance much longer too. A good quality Nylon Looped Berber styles range from $35 to $60, not including pad and install.


All Berber styles require a special padding that is more dense and has a lower profile. For example, a 1/4" to 3/8" thickness and a density of at least 8 pounds. Rubber pad, synthetic fiber or wool felt pads are all good options for any application. Learn more about How to choose the correct Carpet Padding





2. What is Carpet Pile Density?

Pile Density is a mathematical calculation based on the fiber Face-Weight and Pile Height. Think of a heavily wooded forest. The more closely packed together the trees are, the more dense the forest is. The same goes for carpet. 


You want a carpet with the tufts packed tightly together. This helps the carpet resist matting and crushing of the pile and increases longevity. 


Pile Density is a major factor to consider when it comes to carpet durability too, almost as important as the type of Carpet Fiber you select. 



3. What is Carpet Face-Weight?

Face-weight is the actual weight of the fiber used to manufacture the carpet pile, but does not include the weight of the carpet backing. Fiber Face-weight is not the same as Total Carpet Weight, which includes the weight of the carpet backing and the fiber face-weight. 


Most carpets have a face-weight somewhere between 20 ounces and 100 ounces, but the average face-weight for a residential carpet is about 35 to 60 ounces. 


A higher face-weight does not automatically mean the carpet is a better grade; is a higher quality; is more durable; or is more costly.


Fortunately, these three carpet specs are mathematically related which is good news for you. 


If you can figure out one or two, out of the three specs, then you can easily figure out the other specifications using the formulas I reveal below! 


Don't worry about the number 36 or what it means, as it is a constant industry factor with all these calculations. 





4. What is Carpet Tuft Twist?

Carpet fibers, also called yarn, is either extruded or twisted to form a single strand or "filament", These filaments are similar in size to a human hair. 


A bunch of filaments are grouped together and twisted together to form Tufts. While these strands are twisted, heat is applied to "set" them permanently, hence the term "heat set" or "perm". 


This is very similar to the way women might use a curling iron to create and set curls into their hairstyles. The tighter the tufts are twisted together the longer the carpet is able to maintain its "like-new" appearance. 


Below are Tufts that are one-inch long. I have used two colors to show the number of twists. 



The Tuft Twist Rating is based on the number of twists per lineal inch of tuft.


This Tuft has 7 twists and is a sign of a well-made carpet. Frieze styles have tufts similar to this and cost about $35 per square yard and up, or $3.88 per square foot.




This Tuft has 4 twists and is not as good. This is a sign of a lower-grade carpet. Inexpensive Plush and Textured Plush styles often have tufts similar to this and range from $15 to $25 per square yard or $1.66 to $2.77 per square foot and up. More expensive styles have higher Tuft-Twist ratings.



Why is Tuft Twist So Important?

The Number of Tuft Twists is an important factor to making sure your carpet retains its like new appearance longer. 


Frieze styles tend to have a higher tuft twist (over 6 twists per lineal inch) and is why they are well-known for their durability and retaining a like-new appearance longer than most other styles. When you look at a potential carpet to buy you can look at the tuft and count the twists yourself. 


Looped Berber carpets have twisted tufts too, but it is very hard to count them with the naked eye. Most looped Berber styles will state the Tuft Twist Rating posted on the back of the carpet sample or shown on the manufacturer's spec sheet. (ask for it)



Matting and Pile Crush

Carpets with a lower Tuft Twist Rating (of 3 to 5), tend to untwist or “blossom” at the tuft tips more quickly, thus creating a worn out, frizzy looking or matted down appearance. 


Carpets rarely wear out from the loss of fiber, they just start to mat down; gradually lose the luster and shine; and just start to look bad or ugly. Once the tufts have blossomed and become matted down, the damage cannot be undone, reversed or repaired. 

Learn more Carpet Manufacturing Specifications Explained



  • The Tuft Twist Rating is based on the number of twists per lineal inch of the tuft. A tuft that is only a half inch long you would need to double the twist count to figure out what the twist rating is. Still, it's fairly easy to guess the number of twists with the naked eye. Compare with other known-specs carpet samples and view side by side. 

  • The Tuft Twist count usually range from 3.0 to 7.5. Lesser quality carpets will have a lower number of Tuft Twists.

  • The higher the Tuft Twist the longer your new carpet will retain its like-new appearance.

  • Carpet "Blossom" or blooming is a common carpet condition where the Tuft begins to un-twist and starts to look worn out, matted down and ugly! 

  • Some carpets with a lower Tuft twist rating may feature a higher pile density to try to compensate. This enhanced Pile Density will certainly help increase the carpet longevity and durability to some degree. Manufacturers of Polyester and PET Polyester carpets often use this strategy to lower costs and increase carpet durability with limited results. 

  • You will find that carpets made from PET Polyester and Polyester fibers are less expensive than a Nylon counterpart and yet feel softer and provide a higher pile density than Nylon. This is because Polyester is less inexpensive to manufacture. This is why they can afford to create a carpet that is more dense and less costly.





P.E.T and Polyester are very soft fibers and resist stains. 


However neither is very resilient. This means it is inherently prone to matting down and crushing of the pile, especially in heavy foot-traffic applications. 


Polyester is less costly to manufacture and profit margins are higher which makes some salespeople recommend it as a viable option for those with a limited budget.

P.E.T. is an abbreviation that has nothing to do with your pets, it stands for Polyethylene Terephthalate, a plastic used to manufacture 2-liter pop bottles.


If you want your carpet to last a long time and you have moderate to heavy foot traffic, the you might want to avoid carpet made from Polyester. 


I would also discourage you from buying PTT, Triexta or Sorona, aka Mohawk Smartstrand if your home has Moderate to heavy foot-traffic and you prefer longevity and durability over stain resistance. Nylon would be a more durable option.

  • Nylon is the most durable and most resilient synthetic fiber used to make carpet, second to none. It is more costly to manufacture and it is not quite as soft as a P.E.T or Polyester or the Smartstrand (aka PTT or Triexta) fiber. However Nylon will typically last years longer if properly cared for and will resist matting and crushing of the pile better than any other synthetic fiber.





Are New Carpet Warranties Any Good?

New Carpet Warranties are not very good. It's an eye opening experience to read a Carpet warranty, although it's not always easy to understand. 


There are so many limitations and exclusions, and it's obvious they go to great lengths to word it in such a way as to make it very difficult for anyone to substantiate a valid warranty claim. You must also follow their care and maintenance instructions and requirements to the letter or risk voiding the warranty altogether. 


Don't buy any carpet based solely on the carpet warranty limits alone. Make your selection based on carpet specifications and your needs, goals, lifestyle and finally your budget.



When it comes to Pile Height, Pile Density and Face-Weight... 


Not having all this information readily available to you might not be such a big problem if you can find or even closely guesstimate two out of three of the carpet specifications, then you can calculate the third using simple mathematics!

Below I explain in detail what you need to do, and how you can quickly and easily figure out for yourself all the carpet specifications you need to acquire, even if the carpet retailer or salesperson refuses to give you hardly any information at all!





Can I Calculate Carpet Specifications Myself?

YES! Let's assume you don't know what the Pile Density rating is of a carpet you are interested in buying, but you do know the Face-Weight and Pile Height:

  • Use Carpet Specification Rule #1 below...


If you don't know what the Face-Weight rating is of a carpet you are interested in buying, but you do know the Pile Height and Pile Density:

  • Use Carpet Specification Rule #2 below...


If you don't know what the Pile Height is of a carpet you are interested in buying, but you do know the Face-Weight and the Pile Density:

  • Use Carpet Rule Specification #3 below...


Assuming you don't know the Tuft-Twist Rating of a carpet you are interested in buying... 

  •  It is not difficult to guesstimate the number of Tuft-Twists of a carpet you are considering. Tuft-Twist is really quite simple. When you look at a carpet you can look closely at the tuft and easily count the number of twists yourself. You just need to know that it is based on the number of twists per lineal inch of tuft. 





Carpet Specification Rule # 1: 


Face-Weight is the weight of the fiber in ounces. (20 to 100)

Pile Height is a Fraction turned into a decimal (like .75 for 3/4"). 

(Convert your measurement in inches into a decimal using the Conversion Table below)


Formula: Face-Weight x 36 ÷ Pile Height = Pile Density
Example: (30 X 36 ÷ 0.50 = 2160)


In this example, what we know is that the face weight is 30 ounces and the pile height is 0.5 (one half inch). 

We can now use Rule #1 to determine the Pile Density Rating.



Carpet Specification Rule # 2: 


Formula: Density x Pile Height ÷ 36 = Face Weight
Example: (2160 X 0.50 ÷ 36 = 30)


In this example, what we know is that the Pile Density is 2160 and the pile height is 0.5 (one half inch). 

We can now use Rule #2 to determine the Face-Weight in ounces.


Carpet Specification Rule # 3: 


Formula: 36 ÷ Density x Face-weight = Pile Height

Example: (36 ÷ 2160 X 30 = 0.499998 (0.5)


In this example, what we know is that the Pile Density is 2160 and the Face Weight is 30 ounces.  

We can now use Rule #3 to determine the Pile Height in decimals. 

(Convert your measurement in inches into a decimal using the Conversion Table below)

Decimal to Inches (fraction) Conversion Table

0.0625     =     1/16" 
0.125       =     1/8"
0.1875     =     3/16"
0.25         =      1/4"
0.3125    =      5/16"
0.375       =     3/8"
0.4375     =     7/16"
0.5           =     1/2" 
0.5625     =     9/16"
0.625       =     5/8"
0.6875     =     11/16"
0.75         =      3/4"
0.8125     =     13/16"
0.875       =     7/8"

1.0           =     1" 

1.0625     =     1-1/16" 

1.125       =     1-1/8"


Carpet Specifications   Page 2    Page 3 



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