How Long Will a LakeMat or MuckMat Lake Bottom Blanket Last?

I often get the question, “How long will a LakeMat (or MuckMat) last?”

I usually answer, “We guarantee them for three years, but they’ll likely outlive us.” That’s a very conservative answer, so today I’m going whole hog and give you the low down.

If you believe in science, our Mat material will last at least until the beginning of the next ice age. If you don’t believe in science, and think the Earth is only about 8,000 years old, then our Mats will probably last until the Second Coming!

Our mats are made of non-woven polypropylene. According to, it takes 20,000 years for polypropylene to fully decompose in a landfill, (or similar conditions) meaning no sunlight is reaching in.

On the other hand, in a liquid natural gas fire, burning at 1,832 degrees it will last 5 seconds or less…

Let’s shoot for somewhere in the middle, shall we?

Assuming your lake bottom isn’t on fire, the only real enemy of polypropylene is ultra violet (UV) light, the same rays that give you a sunburn. Now if you remember science class, you learned UV light is at the short end of the spectrum and so it breaks up quickly when it hits something, like sediment floating in your lake water. It just doesn’t penetrate very far.

That’s why if you spend all day swimming at the lake, your shoulders get fried but your feet and legs are unaffected, (assuming you weren’t stupid enough to lay out on the shore for a few hours). The deeper you go in water, the less UV light penetrates.

I assume you have a good amount of sediment in your lake, otherwise you wouldn’t be interested in a LakeMat or MuckMat. That sediment is like sun screen for your Mat, protecting it much the same as if it were buried underground in a landfill.

(Note: when asked if I use sunscreen, I reply, Yes, I call it, ‘Stay in the Shade!’)

So how long will a LakeMat or MuckMat last? The steel weights should be fully oxidized (rusted away) in 300 to 600 years, depending on how much oxygen it gets underwater. The polypropylene fabric would last about 20,000 years with no sunlight, so let’s be cautious and use only 10 percent of that number…the fabric will last about 2,000 years.

Yes, there are bacteria that are reported to be evolving to eat polypropylene and other plastics. I’m guessin’ this process is going to take awhile…

Now, consider we’re about 11,000 years into an “inter-glacial” period that lasts at most for about 12,000 years. After that, we’ll have another ice age that lasts between 40,000 and 100,000 years. Your cottage is going to be covered with a sheet of ice about a half-mile high for a long, long time. You won’t care about lake weeds or muck.

According to my “cyphering” that puts the material in your LakeMat or MuckMat lasting into the beginning of the next ice age…or, “Well after the cows come home.”

Okay, I admit my math may be faulty, so let’s say I’m off by another 90 percent, and the material only lasts 200 years…and then just to be safe, reduce it another 90 percent, so your LakeMat or MuckMat only lasts 20 years.

Whether your lake bottom blanket lasts 20 years, or 20,000 years, it’s going to last you a good long time.