Hot Tub Cover Cleaning

A hot tub cover is an important investment for any spa owner. It is your first line of defense for keeping your water sanitized and saves you money by maintaining heat and preventing water evaporation. As a hot tub owner, you know how important it is to keep the water properly balanced in order to keep all of the hot tub equipment in proper working order. However, care for the hot tub cover is often overlooked. In this post, we’ll discuss how to do a proper hot tub cover cleaning as well as give you some tips on how to increase the life of your cover.

About Covers

Spa cover material is a backed fabric, the outermost layer being made of a polyvinyl chloride. During the manufacturing process, that material is given a topcoat with compounds called a plasticizer alongside softening agents that keep it soft and pliable.

The most damaging elements to a hot tub cover are UV rays and mildew. It’s important to maintain that plasticized topcoat in order to keep it looking and performing like new. Cleaning the cover every 1-3 months will keep it moisturized and looking nice for years. You can even rejuvenate an older cover with a thorough cleaning.

It’s important to know which products to use and which ones to avoid. Otherwise, you’re better not using anything rather than use something that’s going to harm your cover.

To clean your cover, here are a few items you’ll need:

The cracking and fading that covers experience is often as much due to the use of damaging products as it is to the harsh UV rays of the sun. Vinyl is very similar to leather in that it requires a gentle cleanser. Don’t use anything that has harsh, abrasive ingredients that will strip off the clear coating on the vinyl.

Here is a list of ingredients you should avoid at all costs in your cleaning products:

  • Alcohol
  • Bleach
  • Detergent
  • Dish soap
  • Oil
  • Petroleum Distillates

If a vinyl protectant has the word “FLAMMABLE” on it, it very likely contains petroleum distillates. While they look appealing when first applied, the shiny finish actually accelerates sun damage by magnifying the rays on the vinyl material. Avoid products like car waxes or anything that leaves behind a greasy or waxy finish.


You can clean your cover in a few simple steps. This should be done anywhere from every 1-3 months:

    1. Remove the cover (careful not to drag along the ground) and wet it with a garden hose to loosen dirt and make wiping down down much easier.
    2. After the water runs off, apply a non-abrasive cleaner to the cloth/sponge and wipe down from side to side.
    3. Rinse the cloth/sponge regularly between swipes and reapply the product to really clean off the gunk.
    4. Clean along the skirting of the hot tub cover, on top of and underneath. Pay special attention to any place that has folds and creases.

Tough Spots

For stuff that may be a little harder to remove (caked on dirt, dried bird droppings, etc.), generously spray on the cleaner, let it soak for 1-3 minutes, wipe off, and repeat as necessary.


If your tub is under trees, you may get tree sap and pitch. This can be removed by rubbing on some margarine or olive oil to the area to break it down. Once it’s removed, clean the area thoroughly. You don’t want to leave any oil behind.

Moss and mildew are likely to grow on an untended spa cover. If you live somewhere humid, you might get moss growing in the zipper and along the stitching where there is heavy creasing. Clean it with your non-abrasive product and use the rough side of a sponge to clean it off. It should lift off within minutes. Pay special attention to these areas during routine cleanings.

If you’ve had areas affected by moss or mildew, it is extra important to use a liberal amount of protectant in the area to coat the surface and prevent it from growing back. The 303 Aerospace Protectant is great for this job.


A lot of hot tub odor problems can come from the cover, particularly if you get mildew growing inside of the cover jacket. You can fix this in a few easy steps (if the problem isn’t too far gone).

    1. Unzip the cover and take out the foam cores
    2. Clean inside the jacket with the cleaner and a soft nylon brush
    3. Clean the core’s plastic vapor barrier CAREFULLY so as not to Puncture the protective covering.
    4. Spray everything down with a hose
    5. Towel dry all the surfaces and allow to air-dry. Additionally, you should choose a day to clean your cover when there isn’t going to be inclement weather.
    6. Letting the jacket dry in the sun for a few hours is a good way to rid it of any residual mildew. Don’t let it sit outside for more than an hour or two to prevent damage to the vinyl. The foam core shouldn’t be left in the sun for much time, either.
    7. Once it has all dried, insert the core back into the jacket. If your foam core doesn’t dry out and is heavy and waterlogged or rotting, it needs to be replaced.

Prolong Cover Life

  • Don’t over chlorinate your water. This can result in puffy and cracking leather.
  • Keep your water balanced. Poor water chemistry can cause vinyl puffiness, stitching disintegration, and bleaching of the underside.
  • Leave the cover off when shocking your hot tub.
  • Remove your cover with a cover lift to reduce stress along the seams, using the handles to gently raise and lower your cover.
  • Don’t lift the cover by the skirting.
  • Don’t drag the cover over the ground, especially concrete.
  • Invest in a solar blanket to keep evaporation from a minimum so that water and atomized chemicals aren’t’ accumulating inside the cover.
  • Secure the cover with latches when not in use to prevent wind damage.
  • Don’t rest anything sharp or heavy on the cover to prevent warping and punctures.
  • Put up a safety fence if you have a problem with animals clawing or chewing on the cover.
  • Don’t set anything glass on the cover that will generate excessive heat by magnifying the sunlight. This heat can melt the core and won’t be covered under warranty.
  • If you get small punctures or tears, use a clear vinyl patch to fix it.
  • If you live somewhere you get a lot of snowfall, make sure to clear off the snow accumulation on your cover. Snow can be deceptively heavy and most cover warranties don’t cover snow or weight-related damage.
  • Some of the cheap or older foam cores don’t taper and rain water might puddle in the middle, further exacerbating the problem. If you get a puddle, unzip the covering, remove the core and flip it over. Sometimes this corrects the problem. If it’s too warped, you will need to replace it.

Core Care

  • The core inserts that go inside the vinyl covering are made of polystyrene which can be marred or broken. Never allow children to jump or play on your cover which can result in breakage. Shoes can also harm the vinyl.
  • The core is typically sheathed in a clear plastic to keep water from soaking into the foam and becoming heavy. Condensation and rainwater seepage between the outer vinyl and clear liner of the foam is normal. Spa covers should have holes in their undersides to let water drain.
  • If you have a great amount of water inside the liner, there’s likely a puncture in the vapor barrier or a break in the seam. Both are easy to fix. A heavily saturated foam core, however, is a problem that is only remedied by replacing it altogether.
  • If you think the liner contains water, open the vinyl cover zipper and remove the foam core. Look for pictures, tears, or openings around the seal. Even a small hole can turn into a lot of water accumulation.
  • Find the hole and drain the water to prevent the foam from getting soaked and heavy. If you can’t get the water out via the entry hole, it can be drained by cutting a slit in the plastic sheeting near the corner. Set the core on an edge (careful not to get it dirty) and let the water flow out of the slit. Getting most of the water out is great.
  • Liner holes can be fixed with a tear-aid kit or small bit of vinyl repair sheeting.
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Harold Wright
July 11, 2015

How do you suggest I clean a zipper all clogged with moss. I need to unzip it to remove/recover/replace the foam. I cannot budge the zipper.
Thanks for any suggestions.

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