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How to waterproof a bell tent

The complete Guide To Waterproofing a Bell Tent

We all know how wet and sticky a camping trip can get when it rains. So, get ready for some traditional tips and tricks for a perfect nights rest out in the wilds. Lets start with a visual guide of the most common technique.

How to Waterproof a Bell Tent

Cotton canvas is a naturally waterproof material in the same way that traditional wooden boats are waterproof, the planks swell and plug the gaps between them, the cotton fibers act in the same way. Both need to be seasoned and wet to become 100% waterproof. It is not advised to apply a waterproofing product to a new bell tent as it may interfere with this process.

Once a bell tent has been left out in the rain or had a hose left on it once or twice, the material should be watertight and will remain so for a while. If you notice leaks at the seams or your tent is starting to wear out, this is the perfect time to apply a traditional fabric dressing or wax.

  1. Pitch your tent and make sure the tent is 100% dry.
  2. Remove dust and dirt with a hard bristle brush.
  3. Apply Ultra Durable Canvas Waterproofing with a brush or paint roller. The cotton needs to be soaked evenly.
  4. You can also apply the canvas waterproofing with a rag or paint it on with a brush.
  5. Let your tent cure in place for 12 hours. Make sure to keep it dry until it’s completely cured.

Bell Tent History

Paraffin Oil/Wax – Paraffin and bees wax has been used for centuries on canvas material to re-waterproof it. This is very similar to re-waxing a wax proof coat. The process entails melting the wax with paraffin or white spirit and applying to the bell tent with a brush. This traditional method needs to be repeated every 6 months or so to remain waterproof and will not protect against UV deterioration and staining. Modern canvas waterproofing blends will only require minor spot applications for years of UV repellent and waterproof performance.

Your bell tent should always be re-waterproofed after washing as detergents will strip away the wax/silicone waterproofing. Click here to read about how to clean your bell tent.

When Should I Re-Proof my Bell Tent?

Is your bell tent showing signs of mildew, mold or beginning to let some water through? It may be time to re-waterproof your bell tent. We usually recommend re-waterproofing your bell tent after 8 – 24 weeks of continuous use. How quickly you reach this stage will depend on a number of factors, the climate, humidity, shade, sun, and use of the bell tent. I.e. is the tent is being used for casual use a weekend here and a week there it could take a few year to reach this point. If on the other hand the tent is pitched permanently or semi permanently you will have to do this every 8 -24 weeks.

The canvas is waterproof, you can tell by the ‘beading’ of water droplets on the outside of the tent. When the water stops that beading (and the tent takes longer to dry out) it’s time to re-proof your canvas.

The most likely place water can penetrate the material is in the seams. If you are experiencing moisture build up around the stitching of your canvas bell tent the likelihood is you’re due a waterproofing! Grab some Fabric Weatherproofer for the task! and check out our article about Waxing Canvas for more detailed info.

What is the Best Tent Material

When looked after properly, canvas bell tents can last significantly longer than tents using more modern materials. This is partly down to the canvas being much more resistant to UV than pure polyester or nylon, which deteriorate when left exposed to the sun for long periods. This is less of an issue in backpacking tents which are pitched in the evening and packed early in the morning. But it’s definitely a factor to consider if you’re looking for a big base camp tent to leave pitched for several days at a time.

Cotton or polycotton canvas already has greater longevity thanks to its UV resistance. But dense weave, heavy-duty canvas is also much more likely to withstand your usual campsite sharps and debris, and polycotton has the added benefit of enhanced tear-resistance.

Because bell tent manufacturers usually prioritize durability over weight, bell tents tend to use much harder-wearing materials and a more durable construction throughout. For example, our Roundhouse uses a sturdy steel pole, big wooden toggles and a heavy-duty 400D Oxford PU floor. It also uses a seamed construction which isn’t dependent on seam taping to stay waterproof. Adhesives in seam taping can get broken down by water over time through a process called ‘hydrolysis’.

How are Canvas Tents Waterproof?

It’s easy to believe that a plasticky nylon flysheet will keep you dry in the mother of all rain storms, but with canvas it’s a little more confusing. How on earth does a sheet of cotton or polycotton keep you dry in the wet?

Well, it’s partly to do with the weave. Canvas uses an exceptionally dense weave of fibers which leaves very few spaces for water droplets to squeeze through. When you pitch a canvas sheet taut and at an angle, the surface tension of the fabric cause water droplets to run straight off rather than soak in.

But there are still gaps in the weave? Yep, but here’s the really clever part. When cotton gets damp, the fibers start to absorb moisture and swell. This swelling closes off any remaining spaces in the canvas, seals up any holes made by the stitching, and ensures that you stay nice and dry while the rain drums down outside.

How To Clean Mold and Mildew on my Bell Tent

How To:

  • Moisten the cotton.
  • Dissolve 1 unit of Moldstop cleaner into 10 units of water.
  • Apply the solution to the wet canvas and let the canvas absorb it for about 30 minutes. Prolong the absorption time if necessary.
  • Rinse the canvas with plenty of water.
  • Let your tent dry properly.

Use Hawk Tools Fabric Moldstop to protect the cotton against fungi, algae, filthy water, etc. A perfect impregnating agent to make cotton tents waterproof is fabric weatherproofer. It is an environment-friendly product, non-toxic and bio-degradable.

Hawk Tools Canvas Waterproofer includes powerful mold and mildew protection for years of clean camping. Never fear storing a damp bell tent again!

AATCC 30 Mold Test



Mold Samples

Prevent Mold on My Bell Tent

Mildew is caused by moisture. It is therefore sure to form on the canvas of your tent if you store the tent wet. Moreover, mold stains often appear on canvas tents if they are no longer waterproof, for they then lack of an important protective layer which would otherwise keep off moisture and mold. To avoid mold and mildew, wipe down the interior and exterior of the tent with clean water before you leave it to dry and store it in a dry, well-ventilated area. Also, reproof the tent in time to ensure it stays mold resistant and waterproof. For more tips & tricks, check out the list below:

How To:

  • Do not roll up or store a wet tent. When you are left with no other option than to store it wet, be sure to remove any mud or dirt from the groundsheet and bottom strip and pitch your tent again within 2 days, allowing it to properly air-dry.
  • Dry off the tent and clean it before you store the tent in a dry, well ventilated space.
  • Ventilate the tent, especially when you do not use it. That way, you drive out moisture, preventing mold to affect the canvas.
  • Do not hang your tent to dry, as mold could form in the folds. Instead, set up the tent outdoors or in your garage and open the doors and windows to ensure that it is being well ventilated. If possible, pitch the tent in the sun, for sunlight may help you in your fight against mold and mildew.
  • Clean and reproof the tent periodically in order to ensure it stays waterproof.
  • We advise you to store the tent in a cotton bag which breathes and does not contain surfactants. A plastic bag may impede ventilation and transfer plasticizers to the canvas.
  • Do not store rings, guy ropes and groundsheet together with your tent, but keep them in a separate bag.
  • Make sure the tent is pitched perfectly, so water can easily glide off the canvas.
  • Avoid touching the tent when it is raining.
  • Be careful with creams, lotions, suntan oil, etc. Greasy hands may affect the tents waterproof performance adversely.
  • Ventilate the tent well when cooking, for condensation may cause mold to appear on the canvas.
  • Do not do the dishes in the tent, for dish water is one of the main enemies of the canvas.
  • Do not hang a kitchen rag over a bar in the tent, as the soap residues may affect the canvas.
  • Do not clean the groundsheet with water which contains soap. Use a dry piece of cloth and a sponge to clean it.
  • Re-impregnate your tent after 12 to 25 weeks of use to protect your tent against solar radiation and extend its life span.

Don't Use Toxic Waterproofing Sprays!

Waterproofing products – There are many different synthetic waterproofing products such as Fabsil available on the market that promise to seal and protect your canvas against the wet weather. These can usually be sprayed or painted on but do contain carcinogens and thinners. Additionally, most require constant maintenance and will not last more than a season.

Silicone spray – Silicone is convenient but the accelerants are toxic to the environment and prevent the canvas from breathing. It can be sprayed on easily and is best applied when the bell tent is up and in dry weather. A popular example is Scotchgard.

Ultra Durable Canvas Waterproofer – We strongly suggest using Canvas Waterproofer to treat your bell tent. It is the most durable weatherproofing agent available and sports UV protection. As a bonus, it’s natural and does not contain PFC’s and is PFAS free.

To Apply

  • Plug in the 12V power cord and wait until the waterproofer is liquid.
  • Use a paint roller or brush to apply the waterproofer to your bell tent in even strokes.
  • Application on a hot, sunny day will accelerate the absorption process.
  • Wait 12 hours for the dressing to cure and scrub off excess wax with a bristle brush.

the right gear

Canvas waterproofer tools gif

Grab yourself a standard paint roller, heat gun, news paper and proper PPE.


Canvas waterproofer read instructions gif

Please read all instructions before use.

Plug it in

Place the can on a non heat-sensitive surface and plug it in.

Hot! No Touch

Canvas Waterproofer Hot Surface

The can will be come hot. Do Not Touch


Canvas Waterproofer Roll On

Once completely liquid, dip the paint roller directly into the can of Canvas Waterproofer and Roll-on in even strokes.

Heat Gun

Canvas Waterproofer Heat Gun

Use a heat gun to re-flow the waterproofer and even out the appearance.