Why is my carpet rippling and lumpy after it got cleaned?That is a great question! We don't always see this happen, but occasionally when we clean, the carpet starts to get large, previously unseen ripples and waves. If you are the average homeowner, those waves are not the thing you want to see in your carpet, especially right after spending a bunch of money on a cleaning that is supposed to enhance and protect your carpet. Rest assured, though, that this is not only normal, it is temporary.

In our parlance, this is called latex displacement. It is also known as expanding differentials or differential expansion. There are several things that can cause latex displacement, most of them dealing directly with the construction of the carpet.

Carpet is made up of 4 layers, which will be discussed in another blog post, but they are, basically: the face yarns (the carpet fibers you walk on); the primary backing, a layer of latex adhesive, and the secondary backing. The primary backing, secondary backing, and the face yarns are held together by the latex adhesive.

Why is my carpet rippling and lumpy after it got cleaned?
Carpet construction. Photo courtesy of Dow.com

The latex adhesive most manufacturers use a type of clay, often made out of marble dust. This helps to give the latex some bulk and to make it spread farther. Unfortunately, this clay also is very hygroscopic, meaning it absorbs water readily. When this clay absorbs moisture, it expands. If there is an excessive amount of water in the carpet or if the humidity is really high that day, this expansion will become readily noticeable, and can cause the carpet to wrinkle or buckle. Depending on the amount of clay in the latex, these buckles can actually become waves, and can be quite disconcerting.

As the adhesive dries, the clay will return to its normal state, and the carpet will lay flat again. An interesting thing about latex glues of this sort- when they are wet, the glue is much weaker, but after the glues dry out again, they actually are structurally more sound than they were before they got wet!

The type and make of the carpet can also affect this displacement. Not all fibers are equal when it comes to water absorption. Wool fibers will retain almost 100% of their weight in water, Nylon up to about 20%, and polyester and polypropylene fibers much, much less. This means that Nylon  and wool carpets take longer to dry, and are more likely to have water get into the backing of the carpet, and to the clay. Looped carpets may also take longer to dry, as water doesn't wick as easily from the fibers.

Why is my carpet rippling and lumpy after it got cleaned?Sometimes, though, the carpet does not return all the way back to its original state, or wrinkles start to appear inexplicably. Several things can cause this to happen, the most usual cause being improper installation. Per manufacturer guidelines, carpets need to be power stretched into place, and then "tacked down." The installer must also use a knee kicker to get the carpet into the proper place on the tack(less) strip, which will hold the carpet in place.

If the carpet is not properly stretched in, it will go back to its original, un-stretched state. As you might imagine, this creates uneven wrinkling in the carpet, because some areas of the carpet will be attached to the tack(less) strip, while others aren't.

The age of the carpet also plays into this condition- if the backings are starting to fail, or if the glue is starting to break down, the stability of the carpet is decreased, and the carpet will start to buckle. This can also be a factor in delamination of the carpet, where the primary and secondary backings become separated. One of the most frequent causes of delamination we find? office chairs with wheels. Putting a rug underneath the wheels of your chair can help eliminate this problem. Improper use of solvent spot removers (Goof-Off, Goo-Gone), or over-saturation (for example, pet accidents) of the carpet can also cause delamination.

Why is my carpet rippling and lumpy after it got cleaned?Around this time of year, we will also start to see more and more wrinkles appear in carpets that were laid over the winter. I always get a funny look when I ask what time of year the carpet was installed. I ask this because carpet is often laid out, measured, and cut in the driveway. It is the promptly brought into the house and stretched into place. During the warmer months, this is not a problem, but in the winter, when it is cold outside, the carpet backing will be very stiff and hard to really stretch into place. As the weather warms up, the carpet backing will relax more, and voila! bubbles start to appear in the carpet.

One last possible cause of carpet wrinkling, though the most unlikely, is manufacturer defect. If the glue was not mixed properly, spread properly, or cured properly, wrinkles can occur. If your carpet has been properly maintained, this could be covered under your manufacturer's warranty. refer to your manufacturer for more information.

So if your carpet reminds you of the Pacific Ocean on a calm day right after your zerorezification™, remember that unless there is a bigger underlying issue, your carpet is fine and will return to normal soon! Please don't hesitate to contact us if you have any other questions!