I have a Snowtrekker 9 x 11.5 shortwall. I got it last year and used it a couple times in the backyard (with my 9 year old). Looking to take a two or three night "trip" with it in late Feb or early Mar. My question is, do I need to invest in a fly for it? I'm not so worried about snow, but if it rains, how well does the fabric do on its own (sans fly)? What are the schools of thought on flys for canvas tents?

I too have a Snowtrekker tent and have spent many a day and night in it under rainy conditions. I've never had an issue.

The fly, according to Snowtrekker Tents, is intended for those instances where there may be a large accumulation of snow while you are away from the campsite........snow will not build up on the fly like it would on the canvas tent. Example---a hunting trip in the Rockies, where you are away from camp hunting all day during a heavy snow storm.

Unless you intend to use the tent under those type of circumstances, the fly would probably not be needed.

Always plan on using the fly if the forecast calls for significant rain or snow. Otherwise, you can get by without it.

I don't think you will need it. A fly for canvas tents is for a long time camp, possibly a month. I own both a Snowtrekker as well as an old-timey Wildwood Canvas tent and have never had a problem. Both have seen quite a bit of time in the outdoors. The Wildwood in particular has been through severe rain and hail and didn't leak at all. When I am drying my Snowtrekker tent, I have to make sure that the melting water that has pooled up on the fabric is brushed off to prevent water stains. The canvas has such a tight weave that water will bead up on it and run off.

Canvas is a great fabric. When it gets wet, the threads of it soak up the wetness and expand, thus making the fabric more watertight, with one caveat; if possible, don't touch the sides of the canvas during a rainstorm. It is possible it could wick through.

If you still feel unsure of it, you can do like I did the first couple times I took my canvas tents out. I brought a tarp that was big enough to drape over the tent if needed. Never had to use it, but it was great piece of mind.

I have several canvas tents, including a snowtrekker. A fly is not necessary for a snowtrekker as the roof has enough slope to shed snow, provided the tent is not left unattended for an extended period, or there isn't a heavy, wet snowfall. So if you don't leave the tent unattended for an extended time. Tents with flatter roof, like most wall tents, should have a fly to help shed snow. One other side benefit of a fly is helps hold heat in, so you burn less wood.

I have ben rained and snowed on for long periods in the tent. It is not water proof, but I've never regretted ot having a fly. If it gets to bad I always have my tarp I guess.