We learned a little about canvas while researching wall tents. After we started camping in a wall tent, we’ve leaned a little more.
If you are also considering buying a wall tent, here is some information about choosing the type of canvas for your wall tent. You can also read our wall tent buying guide that discusses features beyond the different types of canvas.
What is Canvas Fabric?
Canvas is is a heavy, woven fabric that was traditionally made from cotton, but is now also made from man-made fibers like polyester.
Canvas is also called Duck, not because water rolls off canvas like a duck’s back, but from the Dutch word “doek”. Canvas has been used for sails, tarps, tents, backpacks and heavy clothing for centuries.
For a wall tent, look for Army duck (also called cotton duck or shelter duck; example/source for duck material). Army duck is a double fill (warp & fill; lengthwise & crosswise) canvas, which means the threads are doubled by twisting two threads into a a thicker, stronger single thread and this heavier thread is used in both weave directions, making a stronger and tighter weave canvas.
Army duck only means it was made to meet U.S. Army specifications. In the past, army tents were as heavy as 17 oz, but as the joke goes, the tents were so heavy, it took an Army to set them up.
Heavier canvas is not always better and the quality of the tent is determined by the weave and by the water, fire resistant and/or anti-mildew treatments.
Fire resistant canvas will burn as long as flame touches the canvas, but will not burn if external flame is removed. Fire retardant does not prevent sparks from smoke stack from burning “pin holes” in the canvas.
Waterproofing can be a dry silicon treatment or a paraffin treatment, either way, today’s double fill canvas with waterproofing does not leak or seep like canvas used to. New water proofing can be sprayed on canvas when needed.
Anti-mildew treatments are important to keep the cotton canvas from mildew damage after it has been wet. Mold and mildew should have a difficult time growing on polyester canvas unless it is dirty and wet. All of these treatments are important and will help the canvas last longer. No matter what type treatment canvas has, it must always be completely dried before storage.
Another source says the 12.0 oz. double fill canvas has breaking strength of 389 lbs (warp direction) and 241 lbs (fill direction). The breaking strength of the 10.1 oz. double fill and 10.1 oz. double fill marine treated canvas was 216 and 202 lbs respectively (warp) and 153 and 140 lbs respectively (fill).
So, if true that means the strength of 12.0 oz canvas is higher than the 10.1 oz canvas by an average (warp & fill) of 41% while the increase in weight is only 16%. At first thought, this seems to defy normal engineering and physical properties where the increase in weight should be higher than the increase in strength, but hard data is hard to argue against.
So consider 10.1 oz canvas for lighter weight and 12.0 oz. canvas for long term semi-permanent camps. In our case, since we have only camped near the truck, weight is not so important and since we only use the tent about two weeks during the summer and another two weeks in the fall, the 10.1 oz. canvas shows little wear, I don’t think the tent will wear our in our lifetime, as long as we make sure it is clean and dry before storing it. So, In our case, the 10.1 oz. is sufficient, so we saved a little weight and a little money.
Make sure you know how much your canvas is expected to shrink. Some canvas claims to have already been pre-shrunk. I was told to expect 3% shrinkage for one of our wall tents, but some canvas can evidently shrink up to 10%. When I cut the EMT poles for the internal frame for our tent, I planned for the full 3% shrinkage, because I didn’t want to have to re-cut poles every time I set the tent up.
But our tent has not shrunk more than about 1%, so the tent still sags on the frame. Three percent may not sound like much, but it adds up to just over 5 inches for the 14 foot length. I wish I had planned on about half the shrinkage at first even if I had to re-cut the poles later.
Canvas made from polyester should not shrink much.
Other Fabrics for Wall Tent
There are many other fabrics used to make tents today and some wall tents are also made from man-made fabrics.
Polyester Based Canvas – Our newest wall tent was made by Elk Mountain Tents of Nampa, Idaho – the 10 oz. canvas is lightweight (13 x 16 foot tent weighs about 60 lbs) and durable, less susceptible to mold and mildew and less likely to absorb water like cotton. The polyester fabric also doesn’t shrink.
X-Treme Tent Cloth – used in Cabelas’ Alaknak Tents – a 250-denier polyester oxford cloth which is lightweight, very strong, durable and resists exposure to UV rays. We also looked at the Alaknak Tent at Cabelas’, but decided against it after seeing the tent setup and examining the synthetic material. If you read some of the reviews, it is obvious that the material can not breathe, so condensation is a big issue. To compensate for the condensation, the newer tents have so many vent holes that according to some, the tent is hard to keep warm. I was also concerned about snow building up on the complex shaped Alaknak roof and that sparks from the stove would burn many pin holes in the fabric.
Relite is another polyester-based fabric used for lighter weight wall tents. Some tents are “blended” with Relite and canvas, where the roof is made from canvas, but has Relite side walls, end wall and door. These tents are advertised as 40% lighter than the same tent made of canvas.
But I have read reviews claiming Relite starts to show a lot of wear within a few years. So it might be an option when reduced weight is absolutely necessary, but don’t count on it lasting 20+ years like good canvas.