Canvas is a wonderful material to make tents from for many reasons, primarily its breathability! However, it behaves in different ways to more common nylon awnings, so it requires special, tender-loving care.
One of the special features of canvas is that you’ve got to weather it to make it fully waterproof. Here we will try and explain how it works (as simply as possible) so you can avoid any nasty surprises when it might appear like your tent is leaking on first use.
Canvas tents usually come pre-treated with chemicals to make them resistant to water. This makes water bead on the surface of the canvas and run off, keeping it from getting through. So, when you first pitch and put a hose on a new canvas tent, you will notice water beads off very easily – this might make it seem like the tent is fully waterproof already.
Don’t be fooled! There is only so much water this coating can deal with before it starts to soak into the canvas. So, if rain is continuous, or very fine, or if strong winds are battering into the canvas – water will start to get through and be absorbed by the canvas fabric. It will be even more so if you find yourself in all these conditions at the same time!
Don’t let water getting through this chemical coating put you off… it’s actually good news for a new canvas tent as it kicks-off what’s known as the “weathering” process! This is what makes the tent fully waterproof.
Basically, what happens is that the fibres of the canvas absorb water and expand when they get wet and then contract when they dry out. As the canvas dries, it shrinks very slightly to knit the weave together and close up any tiny holes in the fabric. It also closes any needle holes where the canvas has been stitched (as these are usually wider holes, they take a little longer; this is why tents often take longer to weather on the seams).
Sometimes the tent will take a few wetting and drying cycles before water stops getting in completely, but every time this cycle happens the tent will get better and better until its totally waterproof.
The key thing is to remember that on your first glawning adventure: don’t panic if your tent seems to be leaking — it’s all part of the process! Lighting the fire and putting a few towels on the floor will usually help to manage the problem, which will totally disappear over time. On a new tent, water might drip along the seams where the tent has been stitched or a fine mist might come through the main panels of the canvas. The problem can be made worse if conditions are particularly bad: in fine, persistent rain, and strong winds. As the floor of the tent is PVC and water can’t get through it at all, water may collect in pools on top of the groundsheet, but under your matting, giving the appearance that it’s coming through from below when it’s not, so don’t worry. Also remember that this doesn’t usually happen for most people, only people who are unlucky that their first time out with the glawning is in bad conditions for an un-weathered tent.
This might sound like a bit of a bother but don’t fret. The good news is that the weathering process can be accelerated at home by pitching the tent in your garden and letting it get completely soaked by the rain & then let it completely dry. You can repeat this process 2 or 3 times to ensure that the job is done. Ideal conditions for weathering would be really heavy rainfall one day followed by a day of hot sunshine. We don’t live in an ideal world, as hard as we try, so if you’re really worried and want to get this weathering process going you can try to use a hose to soak your tent — but remember to keep going until you’re happy your glawning is actually soaking before letting it dry.