The Ultimate Guide to Waterproofing a Canvas Tent

We may receive commissions when you buy through links on our site.

Every self-respecting camper owns a tent. There is something special about camping in the wild and sleeping in a tent. But usually, we take the tents for granted and forget that they need some love too.

We will soon reach that moment in our life when we will need to wash and waterproof our canvas tent. Of course, that said, all seem secure operations. In reality, there is a need for attention because the camping tent is paradoxical as resistant as fragile. Especially to the corrosive action of specific products, they tend to lose integrity.

Further down, you will find out why it is essential to perform these operations and how to waterproof a canvas tent. Moreover, we will also share some tips to avoid such issues.

How Do Manufacturers Waterproof Canvas Tents?

Some induce the web of chemicals. The problem with this method is that the effects fade quickly. Others use membranes, waterproof films applied to fabrics to protect them from the rain. The latter method is often more reliable and durable and therefore preferred.

How Is The Waterproofness Of A Tent Measured?

The waterproofing of a fabric is measured by placing it under a water tube (water column). The minimum water height at which the first drops of water pass through the fabric represents its impermeability.

The waterproofing of your canvas tent is indicated by the Schmerber index, most often in mm. The higher it is, the more waterproof your tent is. A 3000 mm column of water protects canvas in the event of heavy rain; a 5000 m column protects from heavy rain. But this index is not enough to judge the resistance of your tent to rain; you also need to check the waterproofness of the ground and the quality of the seams.

Even the best tent decreases in quality through use. It is for this reason that you must take precautions before, during and after your stay in your tent. Avoid, for example, using a stove inside, just a clumsy thing for a hot pan to touch and damage a wall. Also, keep your tent away from bushes and animals that may tear it apart. If you ever scratch the canvas, repair it as quickly as possible. Never fold up your tent if it is still wet, and if you are forced to do so by the weather, don’t forget to dry it as quickly as possible.

Index of waterproofing: What are the measures?

This water height corresponds to pressure and is measured in mm. For example, 1000 mm represents 1m of water. Waterproofing can also be measured in the Schmerber index. This unit of measurement corresponds to the number of mm of water height. For example 1000 Schmerber = 1000 mm.

In most cases, we can say that the higher this number, the more waterproof the fabric. But this is not true for all subjects.

For a polyester tent, our measures range from 800mm to 5000mm.

For a cotton tent, our measures range from 250mm to 800mm because cotton is more resistant and more breathable. There is no coating. The fabric will naturally be more waterproof. Often the measurements are linked to the Grammage of the cotton canvas. The higher the Grammage, the more waterproof it will be. We consider an over quality beyond resistance at 250mm.

waterproofing a canvas tent

Why is it important to waterproof canvas tents?

Making a tent waterproof allows you to avoid the entry of water during possible rains, therefore, also to prevent. As a result, the sheets are saved from being damaged, and therefore the product is no longer usable.

For this operation, there are two schools of thought: one that indicates the use of chemicals and another that urges instead to use tents. Both solutions can be successful, although there are always pros and cons to consider.

The advantage of using, for example, a chemical product such as spray, is that it can always be carried with you without taking up so much space in the bag (unlike the use of a tent, which instead requires a special compartment)t.

Nonetheless, professionals’ most popular method is the latter. It merely consists of positioning and attaching a waterproof sheet to the posts, which can cover the entire surface of the tent.

The principles of waterproofing canvas tents:

There are mainly two principles for waterproofing the canvas tent:

  • The piece of fabric is impregnated with a waterproofing agent: this is the case with Polycotton
  • The piece of fabric receives a coating: this is the case of polyester (most tents today)

So How to Waterproof a Canvas Tent yourself?

You have been impatiently waiting for your camping holiday for months, and once you arrive, it turns out that your tent leaks at the first rain shower. Maybe a little bit of water runs down a seam or onto the canvas. This is very annoying because you assume you have a  waterproof tent. Fortunately, in most cases, a leaking tent can be repaired quickly. We’ll explain how to do it.

In most cases, you should deal with one of the following leaks:

  • A leaky seam in a polyester tent
  • A leaky seam in a cotton tent
  • A leaking canvas in a polyester or cotton tent

1. A leaky seam in a polyester tent

Do you have a polyester tent, and does water flow into the tent through the seams during a rain shower? Fortunately, it’s not that bad. When making polyester tents, the seams are coated on the inside. In principle, this means that all the holes created by the wire are closed so that nothing can infiltrate. Sometimes a part is not coated so well, which causes a water leak inside.

A leaky seam in a polyester tent is very easy to repair with a sealant. It is a product (water-based) with which you can quickly seal seams sewn on synthetic fabrics. With this product, you can coat the seams inside the tent yourself. A seam sealer dries quickly, and you are completely dry again the next rain shower!

Tip: Put a bottle of sealant in your tent bag, to be sure you don’t end up with a leaky tent during your vacation.

2. A leaky seam in a cotton tent

Do you have a cotton tent, and you see water seeping through the seams? So you probably have a new tent, and it’s out for the first time during a rain shower. The threads of a cotton tent expand when they are first wet. Once dilated, the seam holes close, and you will no longer leak the next downpour. If you want to avoid this, you can, for example, wet your tent in the garden with a sprinkler before going on vacation.

Have you owned the tent for a while, and it is not the first time that it has been outside during a downpour? So it is good to check if the seam is still intact. You can check this by rubbing the seam with your finger. Are you removing the wire by rubbing? So consult an expert. If the seam is still intact, you can apply 123 or Ultramar sealer to the seam to seal it (this can be done indoors or outdoors).

3. A leaking canvas in a polyester or cotton tent

Polyester: A leaking canvas (with no visible holes) is slightly more challenging to repair than a leaking seam. If the canvas of a polyester tent is leaking, you can do almost nothing. The canvas is worn, and the tent will probably have reached the end of its life.

Cotton: With cotton, the impregnation layer on the tent can be worn out. You notice it most quickly with the wire. In this case, it is easier to avoid leaks than to wait for the leaks. You avoid a leaking cotton canvas by permeating the tent regularly.

Later in this article, we will discuss how and when to waterproof the canvas tent.

How to Waterproof Canvas Tent with Sprayhood & tent Protector?

Thanks to the specially designed impregnation product, you can waterproof the canvas tent without extra work. There are many products available on the market. You can use them following the procedure mentioned below:

  • Make sure your awning is clean.
  • Spray particular Sprayhood & Tent Protector widely and evenly on the dry tent fabric. Use a plant sprayer, paintbrush, brush, or spray can.
  • Spray the interior too! By permeating the interior, mold and weather spots are less likely to adhere to the tent fabric.
  • Immediately remove the impregnating product from windows, caravan, etc. Use a damp cloth.
  • Let the tent dry thoroughly. Repeat the treatment if necessary.

Impacts Of Washing On Waterproofing: When To Wash It And Why?

It may seem strange, but the canvas tent must also be washed to protect its waterproofness. Especially before waterproofing, it is more important to wash the tent. A clean canvas lasts even longer. That is why good practice is to wash it every time you use it, avoiding that any dust or dirt deposited can destroy the surface.

If you use it little, the washing frequency can be lowered even once a year. It is done to be sure and prevent the entry of any water to give the green light to the formation of humidity and, therefore, in cases worse, of annoying molds.

With these little tricks, it will last longer, and you will not find any kind of health problems, even after an entire outdoor season.

Two simple steps to clean it: To make washing more effective, it is advisable to divide it into two distinct moments. If you have been on vacation for some time, before returning and closing it, take a moment to remove the bulk.

  • Disassemble it and with a damp cloth and vinegar clean the metal parts. Then go to the interior, taking care to eliminate the dust, crumbs, insects, leaves, and everything that may have entered.

Once you have made sure that it is clean inside, it’s time for the outside, which is the most delicate. In this case, you risk breaking or puncturing the fabric and destroy the waterproofness. With a light bristle brush, give it a pass, paying particular attention to persistent dirt. In the meantime, continue to disassemble each part until it folds, leaving it as clean as possible.

  • The second moment is when you finally get home, and the time has come to do the actual washing. Put the tent back in the garden or ample space to go over the brush again. Make sure to remove any coarser dirt, and then switch to water and soap.

The latter is essential because it must be diluted in the bucket of water in which you will have to dip a cloth. With this, you will pass the tent’s internal and external walls and then rinse with a pump and leave to dry in the open air.

Store the Canvas Tent to Preserve the Waterproofness

To protect the waterproofness cleaning may not be enough: here is a shortlist of things to do to keep your canvas tent at its best.

  • Never store the tent if it is wet or damp.

Even if you have just cleaned and washed it, never store your camping tent if it is wet or even just wet. The reason is simple: the areas moist develop mold, which finds you the following year and will force you to detergent intensive treatments or changing the tent’s waterproofness.

  • Fold the sheets in always different ways.

The fact of folding the tent and put it away for several months involves always wear, even slight, of the areas of bending. To avoid wearing out too much in the same places, the ideal is always to fold it in different ways.

  • Waterproofs the fabric

You can apply layer-produced waterproofing specific to the tissue to protect the camping tent from any external agents – water, humidity, mold, dirt, etc.

  • Save yourself the nasty surprises.

Have you checked that there are no tears or holes before folding and storing the tent? Did you do a hinge check? And the seams? So many small details that perhaps don’t seem important to you, but when it is time to leave for new exploration, I assure you that they will make a difference.

To keep your canvas tent at its best, remember to check the status of:

  • Fabrics in general: If there are holes or torn areas, repair immediately. Then procure a kit of repair emergency for the next outputs in a tent.
  • Hinges: If they stumble or get stuck, fix them with a little soap, without ever tugging them.
  • Stitching: Do they hold? Are they well waterproofed? If you notice that something is wrong, reinforce it or waterproof it with a specific product, like this one.

If you have found this article helpful to waterproof your canvas tent, please do share it with your friends.