A load bearing hem for the apex of pyramid tents
Introduction
In many of my posts, I have banged-on about an apex hem for holding up my DIY pyramid tents in many magical ways. However, I have never adequately described the particulars of the simple design and the sewing and sealing the hem and stitches with RTV silicone rubber.
Over time, I have also realized that the DIY technique is equally applicable for the modification of a pre-made (new or second-hand) pyramid tent that may be a cheap and quick option. This could be applicable for those who have the combined misfortunes of being; money-poor, time-poor, have no sewing machine or you’r a ‘crap sewer’ like me.
Before we get on with DIY practicalities, I will mention that I started the technique as a sneaky way of having a tent stove flue pipe also act as the tent pole to save weight. The ever-improving heat output of the stove ended up melting the tent pole. As Basil said in Falwtytowers: “…. that particular avenue of pleasure has been closed off”.
However, a sweet legacy of this failure was a magic DIY load-bearing apex hem that is so simple and versatile that it will be hard to beat and has been a feature of my tents ever since.
This post is about the detail of the attachment of the hem to a new tent or retrofitting to an existing DIY pyramid tent and it can be done with only hand sewing if needs-must with rudimentary sewing skills.
Method
Preparing the load-bearing hem for a DIY pyramid tent
A FOUR-LAYERED HEM
Normally, I make the DIY hem after sewing the tent canopy panels together. However, I think it makes more sense to describe the hem first and then the preparation for its attachment. They are both so interdependent, but a ‘stuff-up’ of the hem is much easier to fix than a ‘stuff-up’ of the canopy.
For strength, I like to make a hem with four load-bearing layers in it. Two layers attach to the inside of the DIY tent canopy and the other two attach to the outside (E and F in the photo above).
This balanced layering of the hem on either side of the DIY pyramid tent canopy fabric (B or L) may be mechanically a tad stronger than a one-side join. “However, the main reason for doing this is to hide some pretty ugly sewing and raw edges inside the cover of the large joining zone of the hem.”
It even can look like it was sewn by an expert when finished. “This applies equally to the outside view for approaching tent visitors and for the tent occupants as they stare mindlessly at the ceiling, in the warmth of the stove, just waiting for the blizzard to pass and let the skiing begin in all that deep snow.”
START WITH TWO LAYERS
I make the hem from strong and light tent fabric such as ripstop silnylon. It can be the fabric that the DIY pyramid tent is made of or some other fabric of similar strength.
I cut the hem piece so that when folded over on itself four times will form a hem with a ‘drop depth’ that is about 20mm bigger than the intended overlap with the tent canopy (50-95mm).
In the other direction, it should be cut to be about 40mm longer than the finally formed hem to allow for short rolled hems to be sewn on each end. Let’s call this dimension the hem length and this should be a little bigger than the circumference of the hole that is left in the ‘tent-top’ beyond the joining line of the tent canopy panels. “As always, it is better if the hem is a bit too long rather than too short!”
Next, I fold the fabric in half so that it’s width is halved. After pining , I casually machine or had stitch around the perimeter to laminate these layers together. Alternatively, RTV silicone rubber can be used to laminate them together. “Contrary to my expectations, the rubber glue makes any subsequent sewing much easier.”
On both ends, I sew a shallow rolled edge hem (Three layers~10mm wide). It ‘hides’ the raw edges and reinforces these edges that will eventually form the ‘rub surfaces’ where both ends of the load-bearing drawcord will exit the hem.
Again laminating with RTV silicone rubber glue before sewing makes the hem stronger and the sewing easy.
I also oversew two or three times for added strength. These areas will experience the harshest forces from the drawcord when the DIY pyramid tent is deployed in strong winds.
The last operation is to sew a simple skimpy hem along the one remaining side with exposed raw edges. It hides the raw edges and importantly prepares the load bearing-hem to be sewn to the tent.
“For a ‘crap-sewer’ like me, this last step means that it is one less task to do while doing the critical pinning, tacking and sewing of the hem to the tent top. A professional seamstress like my talented Mum would have rolled the skimpy hem as she sewed it to the tent, but I never reached that skill level.”Again, glueing before sewing makes the hem attachment stronger and the sewing easy.
Preparing the DIY tent panels for adding the load-bearing hem
TRICKY PANEL SEAM SEWING
The panels of a DIY pyramid tent taper to nothing at the apex of the tent. This makes the pattern making and panel cutting tricky. The sewing of the seam is also tricky or impossible (and ugly) at the top. particularly with French (or lay-flat seams or felled seams). If you are an ambitious but ‘crap sewer’ like me the problems get even greater.
This is the segway to my obligatory ode;
I searched for a noun for a male who crudely sews,
Not the obvious word sewer associated with poohs,
Meaning might twist if I correctly used sewist?
Or should I settle for a ‘crap-sewer’, who knows?
SEWING SIMPLICITY
When a magical load-bearing hem is to be fitted to a DIY pyramid tent it requires a special finish on the top of the tent. “Well… maybe not so special, but more….let’s say an incomplete finish.” The technique is rugged strong and simple but ugly. Luckily, the strength will be awesome and the ugliness will be hidden within the beautiful hem. So no one will know, except you and me and of course, the gods whoever she or he may be.
However, all that must wait until you master the art of sewing a French seam to hold your tent panels together. My little post on simplified French seams may help. It is at odds with the conventional methods, but I learnt it from my Mum and it has simplicity and speed and is wonderfully suited to joining straight grain to bias grains as is essential with the best pyramid tents. It also compensates for being a ‘crap-sewer’.
Also, before cutting any tent panels, it may be useful to read a section of the above post headed Lay flat seams with one bias cut edge. I would have benefited greatly from this knowledge when making my first pyramid tents out of slippery silnylon!
SEAM STITCHING
I start sewing my tent panel seams together from the bottom (or the would-be bottom of the tent). Whether through cutting errors or stretching, any unevenness will be at the top. These inconsequentials blemishes will eventually be ‘buried and invisible’ at the top of the tent when covered by the load-bearing hem.
Looking good is a neat substitute for perfection.
Mothy The Elder
A SYSTEMATIC SEWING METHOD
To make the DIY pyramid tent assembly easier and less blunder-prone. The above-mentioned post also has some tips on the efficient ordering of the addition of each panel to the growing canopy.
It also means that the ‘crap-sewer’ does not get overwhelmed by the growing size of the tent canopy. Also, the work can be easily passed under the sewing machine bridge during both lines of the French seam stitching.
The post also explains how to systematically use the straight grain side of the seam to ‘wrap’ stretchy cross-grain side. This can make the first critical line of stitches much less difficult. This is particularly helpful when sewing silnylon that is both stretchy and slippery.
LEAVE ONE SEAM UNSTITCHED
I leave one seam unstitched and eventually fit the full-length zipper to form a walk-in doorway opening. It is essential that the zipper can be opened or released fully at the top end (more on these zippers later).
This feature leaves the massive DIY pyramid tent canopy looking like a beautiful giant cape. The strong ring of cord within the hem is the only component that makes a fully enclosed circle and even it can be untied.
It is so easy to work with while making and modifying the tent. It will forever have many advantages as it is used for ultralight camping as described in ultralight tent.
WHERE TO STOP STITCHING?
I like to measure and mark this stitch endpoint directly from a full-scale cardboard pattern that I use for panel cutting. This helps to avoid creeping errors. It should be about 50-75mm from the theoretical tent apex, depending upon the intended depth of the load-bearing hem. “Remember the hem is easy to adjust to the canopy if the hem is made to fit as the last step.”
A SINGLE PIECE PATTERN
I use a single piece pattern with an A and B side to mark out, annotate and cut out the panels. It changes ‘mind-banging’ complexity to tedious simplicity if your well-designed DIY pyramid tent is as simple as mine. Such a pattern is also described in the above-mentioned post and it can be used to consistently mark the stop point for the seam stitching.
WHAT HAPPENS WHERE THE SEAM STITCHES STOP?
Above the end of the seam stitches, each panel has a little triangular flap left on top. Each little flap can become an infinitely strong attachment surface for connection between the tent canopy and the load-bearing hem. “The bigger they are the stronger will be the attachment if they are generously sewn to the load-bearing hem with ganged lines of stitches. It can be far stronger than most conventional tent tops!”
HOW WIDE SHOULD THE HEM BE?
The short answer is: wide enough to cover the hole left in the top of your tent plus a bit more. Normally my load-bearing hems are far bigger than they need to be to fit a stout bush pole through.
For me, a big hem size is all about providing a generous overlapping join between each of the ‘triangular- flaps and the hem at the top of each tent canopy panel.
Strength is paramount and the rather large cylindrical hem gathers into a perfect conical shape around any pole when under full loading with the drawcord. The pyramid finish and great esthetics are restored, as shown in the photos below.
More importantly, the thousands of unbroken fabric fibers all equally and gently share and distribute the load from the drawcord down to a wide area of all tent canopy panels.
THE MAGIC OF A HEM DRAW CORD
At first, I re-tied the draw-cord loop according to the thickness of the pole, the shape of the top tip or the tree branch (or sky-hook) that I was to hang the tent from.
Then slowly (I am a bit slow), I discovered that a largish size fixed loop would suffice for all situations, especially if the sky-hook cord was tied permanently into the loop. I simply twist the loop until it is the appropriate size to hold on a pole top. It means that all options were covered and nothing would be lost or left behind. “This feature is very suitable for a forgetful person who is always dreaming of other things.”
Lastly, when a bush stick is used as a tent pole it can be selected to have a fork formed above the apex of the tent. Then the sky-hook cord can be passed through the fork and back down through the load-bearing hem to be tied off with a clove-hitch within the tent. This means that for nylon tents that stretch considerably with increased humidity, the canopy can be kept taut by making simple adjustments from inside the tent. It is a great alternative to having to go out in the rain or snow and adjusting many tent anchor points.
ENDLESS ZIPPER OPTIONS
A fully openable zipper that closed toward both ends would be optimal. That is if you can procure one that is suitably; light, strong, long and priced. (Please let me know if you can find suitable ones).
Such a zipper would allow easy opening of the door from the bottom, while it will also open from the top. This ‘top-opening’ feature may be used for very effective ventilation control. It may also be used as an upper-body ‘pop-hole’ for ‘pyramid tent stove’ manoeuvres that hot tenters will appreciate in very bad weather, as described in stove and stove pipe location.
Pragmatic zippers. I always use zippers that can be pulled apart completely either as a single light zipper or a 3 or 4 sequential zippers. Having used both options and I clearly prefer the convenience and simplicity of the single zipper. “It is particularly good when sharing the tent with others who may have bladders that are not as good as mine.” However, such long zipper may also be difficult to procure and are not ameniable for providing ventilation at the topof the tent.
One long and one medium zipper. An upside-down medium-length zipper at the top of the opening can be used for the ventilation and ‘pop-hole’. Below this, an adjoining long zipper that opens from the bottom makes an excellent General access doorway. The combination of both is almost as good as the elusive double-end zipper.
They give excellent lower access for pee-breaks at bed-time. Can provide separate ventilation and upper-tent access for ‘tent stovies’. Together they can both be opened and allow full walk-in access when setting up or packing up camp and when rapid drying is required.
Zipper in snow skirt. I add an ultralight wind/snow/insect skirt or partial floors around the perimeter of my tents. These skirts normally overlap with two groundsheets that can be placed so that they leave a safe space for the tent stove operate in and also a wet area near the doorway for wet clothing, boots and snow-coated items.
To make all this work well, I run the door zipper through the skirt at the doorway. This keeps the skirt tight when it is most needed but it also allows the partial floor to lay out flat with the rest of the tent for quick drying.
SEALING OF THE HEM STITCHES
At first, I was reluctant to sew many little holes in the DIY tent canopy while fitting the load-bearing hem. That concern has dissolved with experience, as the top of the tent has never leaked rainwater in. However, I do brush in some RTV silicone rubber that had been thinned with mineral turpentine (tricks for silnylon seam sealing).
I do the sealing of the stitches while doing the same for all the French seams on the tent panels. I can not say if the sealing process is necessary. However, I notice that the sealing treatment leaves the thread of the stitches with a waxy and water-repelling finish. This can only be good for keeping water out.
RETRO FITTING OF A LOAD BEARING HEM
While I have no example of a retrofitted load-bearing hem to an existing tent, I can see no reason why it would not be possible or practical. It should be as simple as unpicking the seams for the required length and adding the hem. A full-length zipper could be added if not already fitted. Alternatively, an extra zipper could be added above the existing one.
Tim
