moisture barrier padding

Does moisture barrier padding work?

It doesn’t matter if it comes from the basement, dog urine, or a kicked-over cup of juice, moisture problems are a big headache. Since liquids absorb through all three layers of the floor (carpet, padding, and subfloor), it can be virtually impossible to remove all traces of an accident.

To “make your life easier”, retailers will likely try to sell you waterproof padding. Just as the name sounds, moisture barrier padding manufacturers claim that it creates a seal that prevents liquid from passing from the ground up through the carpet and the carpet down through the floor board. In theory, this keeps ground moisture from flooding your basement and prevents dog urine from seeping into the subfloor wood.

But is it really waterproof?

It definitely repels liquid. Your retailer may even demonstrate by pouring a large glass of water on top of a sample. But is repelling liquid what you really want? Not necessarily, you just want a pad that limits the damage of dog pee and basement flooding. Does the moisture barrier eliminate these problems? In some cases it does, but in many cases, it makes the problem worse. Read on to figure out when you might want to invest in moisture barrier padding and when it’s not worth your hard earned money.

Making the moisture problem worse

The biggest problem with a moisture barrier is it can make things worse. Picture this: for some reason, there is a crack in your moisture barrier right where a spill occurs. This spill seeps through the crack, and the fluid rests on the floor board. Now the liquids trapped under the padding because the barrier doesn’t allow it to evaporate back up. Pooled water in a dark space is a great habitat for mold growth. You may be thinking, “isn’t it pretty unlikely that a crack in the padding will occur right where I spill?”

Installation is more important than ever

Liquids have a way of finding any imperfection or break in the moisture barrier padding. This requires special installation that seals the gaps between segments of the pad and doesn’t involve staples. Instead, the padding has to be glued down, and then duct tape or other waterproof tape is used to seal the seams and edges near the wall. The installer has to know what they’re doing or this padding is doomed. Even when they do a great job, sometimes the liquid (especially when it’s near a wall) finds its way underneath the padding.

Basement moisture spells disaster

You might find a retailer who sells you moisture barrier padding to fix your basement moisture problem. But when you really think about it, moisture barrier padding doesn’t make sense in a basement. Basement moisture comes through the ground, and it’s going to whether or not you have a barrier in place. In fact, the moisture barrier could make things worse, much worse. The barrier will do its job to repel the moisture, but now the moisture is trapped between the concrete floor and the pad. The stale water acts like a petri dish for mold.

Animal accidents

Animal urine is one of the most common moisture problems facing homeowners, and it’s also one that moisture barrier padding can make much less problematic. Typically, urine absorbs through padding and into the floor board. Eliminating the bacteria and odor from urine that’s penetrated the padding requires pulling up the carpet and pad—not a cheap fix.
This is where moisture barrier padding comes in. If it’s installed correctly, the urine will pool on top of the padding, instead of penetrating it. Then, the fluid can be sucked up without seeping into the floorboard. Keep in mind, if you don’t get all of the urine up, it will be sitting on top of the padding and underneath your carpet, which can lead to a pool of bacteria. It’s worth investing in professional help to make sure as much of the urine as possible is removed.

New breathable moisture barrier pad

What if you could have a padding that acted as a barrier to spills and urine from soaking into the floor below, but was “breathable” in the direction of the subfloor to the carpet? Theoretically, this would eliminate all of the problems of moisture barrier padding (trapping moisture between the subfloor and padding) and would still have the benefit of stopping urine and spills from absorbing through the padding.

Today there is such a padding, but does it live up to its claims?

I don’t know that the padding has been officially tested by someone not paid by the company, but it’s currently made by Stainmaster, and they’re generally considered a reputable company in the carpet industry. I believe it propels moisture very well because we’ve already seen that in other moisture barrier pads. How well it breathes is the big question. I’d guess it does breathe more than normal moisture barrier but less than standard padding. This means the padding may be beneficial for pet owners or families, but is the benefit really worth the cost? There’s no perfect answer here. If you have a big problem with animal accidents or children spilling on the carpet, you may be the person to splurge on this technologically advanced pad.

Captain’s parting words!

For the majority of cases, moisture barrier padding gets the thumbs down. It comes with over-hyped marketing that can’t live up to its claims. In some cases, this special padding may even result in more damage than if you had a traditional pad. The people who may want to consider moisture barrier padding are pet owners and families with children who spill frequently, but it’s important that if you go this route, you don’t have a moisture problem in your home (it sounds weird typing this, but “moisture barrier padding” can make basement or other floor moisture and flooding problems worse). If you decide to buy moisture barrier padding, it’s worth looking at the breathable versions since they claim to solve the issues of other moisture barriers.

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Jorge J Vargas

I just moved in to a 1st floor studio apartment. Previous owner was there for 30 years. Pulled up the the carpet and there was very old 8 inch by 8 inch interlocking low end plywood flooring tiles. I pulled up that floor and am down to the concrete floor. Some of the wooden tiles look like they suffered some kind of water/liquid damage and the underside of the old carpet also looks like it has stains from some kind of water/liquid. Maybe water as there is baseboard heating and it looks like the pipe leaks. I am not sure… Read more »

Darcy Contomanolis


I have a new area rug 5 x 8 and thinking about geeting an 8 x 10 . My oldest dog sometimes has accidents. I would like some type of not very thick plastic that I could put underneath so it doesn’t go through to hardwood floors. Also than if I want I could either dis-guard or wipe off urine from the plastic. Thoughts??

Barb Hill

Hi I live on a concrete slab and have two dogs ho sometimes urinate on training pads but sometimes miss! I installed padding with the water proof cover. Then installed berber over it. The balance of the house has berber that is 19 years old but has regular padding on it. Why is it when I shampoo the new carpet the carpet cleaner does not soak up any liquid but when I do it on the old carpet it does? I first thought it was the carpet cleaner but when I saw water being sucked out of the old carpet… Read more »

Candace Scarlata

Do you know anything about the effectiveness of a waterproof backing that comes on the carpet? We have pets so want to protect our pad from possible urine smells, so we are debating between getting a pad with a moisture barrier or getting a normal pad paired with a carpet with a waterproof backing (specifically, Shaw’s titanium twist series called platinum series). Are there any drawbacks to having the barrier as part of the carpet rather than the pad?

Penny Conklin

We purchased the padding with the pet protector on it and we don’t have any pets any longer. What we have found after several years is that the waterproof barrier must be separating from the pad because after we vacuum the carpet there is a crinkling noise when we walk across the floor. After a few days it goes away until we vacuum again! Will not be buying that type of padding in our bedroom thus time around.


Hey Captain, I am replacing my carpet in the upstairs bedrooms. I do have pets and one of them is older and will urinate on the carpets. I am planning on kilzing the subfloor prior to the carpet install. Is this a good idea or do you have a better one? Do you have any suggestion on brand/ type of padding or carpet that I should consider? Where should I considering buying from, Home Depot, Lowes or another flooring distributors?