When we bought our wall tent, we also bought an angle kit for an internal frame. To save money on shipping, I bought 1 inch EMT tubing at the local building supply and cut the poles myself. The Angle kit consists of 3 and 4-way connectors that are welded from 1¼ inch (inside) galvanized steel tubing that hold the 1 inch (inside) EMT tube frame together.
I was told to plan for 3% shrinkage, so I cut the tubing accordingly, but after four years, our tent has shrunk only about 1%, so the tent hangs very loose on the frame.
If you don’t plan for shrinkage, the tent may not fit over the frame and you would have to re-cut poles before you could set the tent up. Now, I wish I had planned on 1% shrinkage instead of 3%. It’s not a big deal to cut another inch of each poles after a couple of years if necessary.
How Many Rafters Does your Wall Tent Need?
The first consideration for your internal frame of your wall tent, is how many rafters do you want or need?
Our 14 foot tent has four rafters, making the spacing between rafters four feet eight inch spacing between rafters. For a 14 foot long tent, four rafters is marginal for structural support.
Three rafters (7 foot spacing) are probably too weak to support the tent in all but the kindest/gentlest conditions like setting up in the back yard for a slumber party. If the tent will be left for days at a time where snow could build up, it would collapse with four rafters.
So reducing the number of rafters reduces the cost and the weight, but in most cases, anyone using the internal frame isn’t planning to be far from the truck. Most people packing a wall tent by horse or 4-wheeler leave the internal frame at home. While more rafters increases the cost and the weight, it also increases the amount of snow the tent can support. Table 1 shows the spacing in inches between rafters (pre- shrunk) for 12, 14, 16, 20 and 24 foot tents with various numbers of rafters.
Very few people will need more than 7-10 rafters, but I can envision setting up a large wall tent in a semi-permanent situation like a summer camp or scout camp, so I have included up to 17 rafter sections so rafter spacing is reduced to 18 inches for a 24 foot tent.
Table 1. Spacing (Inches) Between Rafters for Internal Wall Tent Frames.
|Rafters||12 Ft.||14 Ft.||16 Ft.||20 Ft.||24 Ft.|
Think of the rafter spacing and strength this way:
- 60 -72 inches - backyard use only
- 48-60 inches - light duty, short term use in fairly good weather
- 36-48 inches – can support a few inches of light snow
- 24-36 inches – can support a foot of light snow
- 18-24 inches – for semi permanent base camp
Keep in mind, heavy snow can collapse any tent if not cleared off regularly.
How Many 3 and 4-way Angles Do your need for your Wall Tent?
This is simple, especially since all end rafters need three, 3-way angles for a total of six. On both ends, a 3-way angle is needed for the peak and one on each side where the roof meets the wall. Every wall tent needs 6, 3-way angles. Table 2. shows the number of 3 and 4-Way Angles needed for various number of rafter sections.
All interior rafter sections need three, 4-way angles. So as shown in Table 2, if using three rafter section, that is two end rafters and only one internal rafter, so only 3, 4-way angles. If seven total rafter sections, that is five internal rafters, so 15, 4-way angles are needed.
Table 2. Number of Angle Pieces and Rafter Sections needed for Various numbers of Rafters for Internal Wall Tent Frames.
|Total||Angle Pieces||Number of Sections|
If you are considering getting a wall tent, also consider an internal frame. It sure makes it easy to set up camp when camping near the trail head. When using a wall tent instead of a camping trailer, it is much easier to get to those remote trail heads on bad roads. Obviously, if packing the wall tent into a roadless area with horses, the internal frame would be left behind.
If you are planning to buy an angle kit, I hope this post helps makes it easier for you to decide on how many rafters you need and also don’t plan on too much shrinkage in the beginning.