It is easy to assume that canvas is already waterproof, after all, it is a very durable material.
Alas, as someone who has been camping in unexpectedly wet conditions, I can say that while canvas does have some natural water resistance, it is most certainly not waterproof.
If you have been wondering do canvas tents need waterproofing, I can assure you they do!
Canvas has natural waterproofing properties but it is not fully waterproof. If you would like to waterproof your canvas tent, you will need to treat it with a special waterproofing spray. There are different types available but the best ones are either silicone or fluoropolymer-based.
It’s not just a question of your canvas tent just getting wet. As the water seeps through the tough fabric, some will be trapped and it will begin attracting mildew.
That will then give rise to that familiar musty smell that comes with mildew and you’ll be sorry you didn’t take the time to waterproof your canvas tent.
The Waterproof Qualities of Cotton (Canvas)
Traditionally manufacturers waterproofed their canvas material using cotton, which has natural waterproofing qualities.
Cotton fibers swell up when they get wet which makes the material denser and less penetrable.
The problem is that unless you thoroughly dry the material out soon after getting wet, some of the moisture will be trapped in amongst the fibers and it will start to attract mildew.
It will then start smelling musty like a lot of old tents do.
Modern Material
In modern times, canvas does not refer to one specific material but rather a range of fabrics that manufacturers then coat with either vinyl-coated or acrylic-based material.
The resulting canvas has a much tighter weave than ordinary cotton canvas and is more water-resistant.
How To Season Your Tent
You may or may not be familiar with the term seasoning’. It is a waterproofing process that you use to seal up any small pinholes in the fabric of your new tent.
Basically, you soak and dry your tent several times. This will cause the materials fibers to expand and seal up any little microscopic holes that you can’t necessarily see with your naked eye but that will attract moisture and mildew if left untreated.
The easiest way to do this is to erect the tent and spray it down with a hose. Alternatively, you can put it in a large bathtub and leave it soaking for a while before getting it out and hanging it across your laundry line. Don’t tumble dry, however, unless the manufacturer’s guidelines specifically permit doing so.
This basic waterproofing process should be sufficient for a while but in time, as your tent starts to age, you may start noticing little leaks from small pinholes in the fabric.
That’s when you need to start applying a silicone-based waterproofing product if you haven’t already done so.
How To Waterproof Your Tent
Even if you season your tent when you first get it, it is still advisable to waterproof your canvas tent however durable you think it may be.
As your tent ages, the fibers start getting that little bit looser, tiny pinholes start appearing and the material loses most of its natural waterproofing properties. That’s when you are going to want to apply a waterproofing product.
What you don’t want to do is use a product that is going to permanently seal up all the fibers. That might sound like a good thing but actually, if the fabric loses its breathability, you’ll get a build-up of condensation whenever you are in the tent.
The trick is to use a sealant that waterproofs without permanently sealing the fibers so that there is still some ventilation.
There are several ways of achieving this but one of the easiest ways is to use what is known as a canvas preservative. You can pick it up in most camping and home improvement stores or online.
What Do You Use To Waterproof Canvas?
When deciding which product to buy in order to waterproof your tent you need to consider the size of your tent.
If your tent is on the larger side you can buy concentrated canvas preservative that can then be either sprayed on or, alternatively, rolled on. Here are a few examples of products I have used myself in the past:
- Atsko Silicone Water-Guard
- Kiwi Camp Dry Heavy Duty Water Repellent
- Obenauf’s Odorless Waterproofing Spray
If your tent is on the smaller side you can just purchase a small spray can which should be sufficient for most small tents designed for just one or two people.
How to Apply The Waterproofing Product
Ideally, you want to follow these steps on a warm sunny day when it’s not too windy. If the wind is too high, you’ll have trouble spraying the canvas waterproofing spray on evenly.
Just follow these five simple steps:
- If your tent is looking a little weathered and perhaps smelling of mildew, get a bucket of soapy water and give it a good scrub using a firm brush then erect it somewhere in your yard.
- If it’s already in pretty good condition just put it straight up.
- Spray the whole tent as evenly as possible. You want to make sure you get the spray everywhere including all the little folds and especially down the seamlines.
- Next, take a little paintbrush and work the application in around any hard-to-reach areas that the spray might not have sufficiently coated.
- Leave the tent to dry before making a second application and leave to dry again. If you are not fully satisfied, you can make a third application but two coats are usually sufficient.
After the tent has dried out, spray it down with water and you should notice that the water starts forming into little beads. That’s because your tent is now waterproof and the water can’t penetrate the surface!
Final Thoughts
I hope this post has helped you understand why, even though your tent probably has some natural waterproofing, you will still need to waterproof it as it starts to age.
Waterproof your tent properly and you won’t have to worry about the smell of mildew each time you go camping but more importantly it will last you for a very long time!
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