A pyramid tent vestibule- turn a mid tent into a winter palace

A pyramid tent with an improved high entry vestibule suited to poor weather conditions is described. It will only add 13% extra fabric weight.

Over my now long lifetime, which spans the advent of synthetic and even non-woven fabrics, I have been a fan of pyramid tents. Their simplicity, strength, comfort, lightweight and versatility is unrivalled when shared between two or three or more people. I am happy to see that for example, Chris Roane endorse this.

I have found that they are ideal for a mix of terrestrial and snow camping, which can often be required on a single winter backpacking trek on skis snowshoes or boots. I have traditionally made my pyramids with a bell wall to maintain head clearance with a minimal footprint area and walk-in entry as shown in the photo below. This design also allows the same tent to be pitched low for storm survival when things get rough.

This post is about scaling up my previous pyramid (2,660mm square) to become a 3,000mm square to optimise the use of 1,500mm wide fabric. I was also testing a design with a vestibule that would provide: pure pyramid pitching on deep snow with greater accommodation, more head clearance, a drier entry in bad weather and better ventilation while maintaining all the ‘old features’. The fabric weight would only increase by 13%, and should substantially increase the comfortable shared sleeping capacity. It would provide more head clearance and the space for gear storage and a centrally located large downdraft tent heating stove.

While I have made a new tent according to this design, the ideas and modelling could be helpful to those who may wish to modify an existing pyramid or a secondhand pyramid to make it more winter-worthy.

Background to my pyramid tent vestibule project

Pyramid tent design model. During previous projects, I created various mathematical models to design pyramid tents. It enables me to quickly determine the efficient ‘cut’ of the available fabric, relative weight and functional features of pyramid tents of various sizes. In this project, I used the square pyramid tent model as my starting point.

While considering the various options from the model, I concluded that a square footprint was optimal to house rectangular sleeping mats efficiently. I also confronted some of my remaining pyramid tent designs features that were less than optimal (“Or should I say, more positively, they were areas for design improvement?”) as listed below:

Poor weather protection when opening a pyramid tent doorway. I have enjoyed a full-length doorway zipper for easy set-up, and comfortable tent entry and exit, particularly when wearing snow gear after being out in it for a day. This full opening feature makes the seam sewing easier and also makes tent drying quick and easy for packing up camp.

However, in bad weather when it is precipitating rain or snow the open doorway allows rain and snow in when moving in and out of the tent. “Crawling in, as for many tents, is not an acceptable option for me!” The area beneath the doorway becomes a wet mess area. I use it for us to enter the tent and remove boots, snow and draining wet gear. However, having extra rain and snow from the sky is an unwelcome addition to the mess.

PARKI thought that this issue could be addressed by forming a pyramid tent vestibule. This could be done by adding a sloping ridge or beak on one face of the square pyramid. In doing so, the peak could be closed from the weather with a vertical wall with a central zippered doorway opening. The zipper could still continue along the newly formed ridgeline to the tent apex (as has been my preference in my previous tents). It could be opened further in good weather for easy walk-in access, perfect ventilation and viewing the stars. Alternatively, it could be closed down lower for stooped entry in very bad weather.

Addition of a winter entry vestibule to a pyramid. Adding a vestibule to one face of a pyramid tent can create a better winter entry doorway. The area adjacent to the vertical doorway will be dryer, have better head clearance and be generally much more serviceable. It can be used for trouble-free defrosting, draining of clothing prior to drying on a line strung across between the apex and the vestibule peak.

I find that the air that is high up in a pyramid gets unpleasantly hot when a tent stove is running so drying lines that extend into that zone would be great for clothes drying.

Increasing pyramid tent vestibule head-clearance. While camping on deep snow during ski trips we dig and tamp snow steps that lead down into an excavated snow pit to provide more standing room and comfortable seating around a central stick burning tent stove.

Inevitably, with group snow trips, such a tent becomes a communal tent for respite from the cold when the skiing is over or a little rest break is required under heavy snow conditions. “To be able to escape into warm seated comfort with friends in the midst of a winter wonderland greatly enhances the winter fun with falling snow. You know that you WILL have the joy of ‘first tracks’ for your next turns. Who said there were no such things as friends on a good powder day?”

This communal activity often means that the remaining space for sleeping mats is small and suboptimal. I usually am offered an alternative sleeping place in another tent as a trade-off. A slightly larger tent with a high vestibule entry should provide a cosy tight space for seating a crowd around a stove as well as leaving a generous sleeping space for two or more people beyond the snow pit. This extra functionality will also be enhanced by pitching the tent as a pure pyramid (as considered in the following mathematical model).

Can a pyramid tent vestibule wall provide better weatherproof venting to further reduce condensation? I have successfully made and tested an experimental breathing pyramid tent that was made out of cheap polyester umbrella fabric (Photo above). This design made a delightful reduction of the condensation problem when tested, deliberately without any ventilation, alongside an equivalent silnylon tent that had ventilation.

The polyester also stayed taught without sagging and flapping with no need to adjust guy cord tension, as with the silnylon tents, during cold and windy nights. The tent also dried more quickly for early cold morning pack-ups on the trail. However, there was still scope for condensation improvement that may come from a large vertical netted ventilation surface. “Even if it does not improve the residual condensation it will be welcome during warmer weather and bug season.”

One side of the wall on the end of the new vestibule extension is permanently fitted with no-see-um netting window as a simple fixed option for good ventilation in water precipitating weather (liquid or solid). “I avoid calling it bad weather as the precipitation of fresh snow is always welcome to a die-hard skier.” The amount of venting could be conveniently regulated from the inside of the tent by adjusting the tent fabric coverage over the netted opening. The other half of the end wall will be used, as normal, as the entry to the tent via the wet area.

The design project for a pyramid tent with a high vestibule entry.

This post is a work in progress and I will add to the post as I make progress and would welcome any feedback from fellow DIY mid fans.

Not another pyramid tent design model!

Using a square model from my pyramid tent design post, I modified it so that it only computed ‘square tents’ (not rectangular) and could be simply scaled to any size according to a chosen base width input. Then I extended the model to have it calculate the dimensions of the tent panels that include the vestibule with a raised sloping ridge or beak and commensurate wall panels to close between the beak and the ground.

Note: If you are interested, I can send this spreadsheet model to you if you send me a request by my contact form or by posting a comment below.

Adjustable door height for a pyramid tent vestibule

A low vestibule peak height makes the tent more wind stable and the holding guyline can be shorter (As in the photo below.), but the entry is less convenient, and comfortable and would provide poorer venting opportunities (as described above).

In contrast, a higher peak height can provide walk-in comfort but will increase the length of the guyline required for stability and increase wind loading. A bush stick can be used to allow the use of a shorter guyline or even better if camping in trees a suitable tree can be used to stay the guyline. This approach complements my preferred poleless tent pitching method that is described in my post; Tent stove location-optimization and A load-bearing hem for the apex of pyramid tents.

Consequently, the model was modified to allow the designer to adjust the height of the door entry according to their chosen compromise*. This allows the designer to select an appropriate doorway height for either full walk-in comfort or stooped entry without the need for crawl-in entry as is the case for many tents.

Note*: A third option may be to have a high entry height that can be adjusted lower for storm survival, but that will have to wait for another day.

A simple pyramid or pyramid with a bell wall can it be both?

In my youth was inspired by the design of a Blacks tent (belonging to Buce M of YHA fame). I copied it and added a breathing nylon bell wall to the PU coated nylon canopy. “My love affair with DIY bell pyramids has continued to this day.” The bell wall did not improve the condensation as it was too low down to be effective, but it enhance the ‘sleeping head’ clearance for multiple occupants while keeping the footprint as small as possible for camping amongst trees and rocks.

When I was discussing my post about optimization of stove location, with Darren Jakal, I discovered his wonderful FTR pure pyramid tent design. Darren excavates snow from under the pyramid as a substitute for walls and this makes the space in the tent very generous and comfortable for three people with a central stove.

This was a moment of enlightenment for me. I decided I will have my new design pitch both as a pure pyramid (like Darren’s) or a smaller pyramid with a bell wall (like my traditional tents).

The tents could have the best of both designs and they would be simpler to sew without curving seams on the corners where the pyramid transitions to a wall as in my current design. It also will facilitate easier addition of the raised entry vestibule as described in this post.

Mothy The Elder

Dual high pitching as a winter palace or low pitching for storm survival. Can it be done with a pyramid tent vestibule?

The photos below show my first beloved 12-sided silnylon pyramid tent. “It was mockingly called a ‘circus sideshow tent’ by friends when I shared it with another bearded trekking friend. The theme was that they wanted the two bearded ladies to do their singing act!” It could be pitched high for comfort or low for storm survival (The tent, not the voices).

I think this new design should allow the tent to be pitch high as a ‘winter palace’ or low as a ‘storm survival shelter’ as has been the case with all my previous pyramid tents. It would just mean that some extra tie-out tags* would need to be added to the tent.

Note*. My unusual tie-outs are made from scraps of tent fabric and are simple, light (~1-2g) and absolutely minimal. I now elegantly integrate them into my tent lay-flat seams, using silicone glueing, as described in the current post. This has now evolved to the use of heat welding as described in Hot knife cutting/welding as seam preparation. The tabs can always be retrofitted: Retrofitted tie-out tabs. In all cases, they have stood the test of time (Never failed, even with drunk people or wild animals blundering into guylines.

I can always fall back to external retrofitting tie-outs as an option if the planning is stuffed up or we could use these tabs to retrofit them to old or second-hand tents that would benefit from more anchor points.

Note*: For the making of the current tent, I used a hot cutting knife to make the pannel cutting accurate and easy. Toward the end of the project, I discovered the fabric welding potential of the hot cutter knife that can suffice for the above glueing for both seams and the tacking of tie-out tabs in preparation for their embedding within the lay-flat seams. For more hot knife tricks, please see: Hot knife cutting and welding.

Order of addition of each pyramid tent panel?

There are many ways that people use to add the pyramid panels together. In this MYOG post, Jerry suggests “…if I have 8 panels, I sew pairs together to get 4 assemblies.  sew pairs together to get 2 bigger assemblies.  Sew them together…..”.

I also did it in a similar way for my first tent. I made many sewing blunders in the turmoil! Now I find that the sewing is more relaxed and less prone to errors. I start with a doorway panel and systematically work my way around my numbered panels adding one at a time (two or three a night) till I reach the other doorway panel.

This means that all the sewn-together panels can be neatly folded on top of one another and clipped together with hobby clamps. They can be left that way while each extra panel is added to the stack. The folded and stacked panels never need to pass under the sewing machine bridge. Only the single thickness of the most recently added panel need to be passed under the bridge while sewing the second line of lay-flat seam stitches.

Fabric seam grain alignment for pyramid panels.

Pyramid tent seam sewing convention usually has seams joined bias to bias cut and or straight to straight grain. (For example; Darren’s DIY FTR pyramid snow tent and Tojahech DIY pyramid tent) or the many commercial pyramids such as MLD Duomid).

Silly me, after making my very first nylon pyramid tent this way, I found that the bias to bias seams were very saggy and ever since I have sewn them together with the bias grain wrapped in the first fold of the straight grain portion of the lay-flat seam (As shown below). Such seams are finally finished with two lines of stitching as a lay-flat seam or more correctly an ISO 4916 2.04.06 seam type.

Toward the end of my first post on a square or rectangular pyramid tent design model, I tested a scale model polyester tent with the conventional bias cut seams sewn as straight seams and then with crude catenary curving. In either case, I felt that the seam could not be pitched very satisfactory or taught way. This may be caused by the properties of the polyester fabric as these problems are not evident in silnylon tents with bias/bias seams as listed above.

“However, I will use some of my vast quantity of polyester for the current project. Consequently, I will continue to use my funny mixed grain seams that are not perfectly taught, but are perfectly good for the task and they don’t require fiddly catenary curving that inevitably ‘steals’ tent space and head clearance.”

The invaluable paper model of the pyramid tent and vestibule

I haven’t had an ode for a while. CovidXXX’s sneaky evolution to keep ahead of us might be eroding my sense of humour, so here is an ode to the tinkerer’s paper model:

Waste time modeling with paper and sticky or glue?
Yes, before cutting your precious fabric new,
Wasting recyclable paper is so darn cheap,
From that mess in horror corner you keep,
Better lesson with paper, than many stitches to tediously undo.

I hope the photos of a paper model of the tent may explain the concept far better than my words can. “I was also delighted that the paper model with dimensions calculated entirely by the mathematical model actually concurred with the idea, that until then, was really only floating in this tinkerer’s head. The good fit of the paper model pieces is another validation of the calculations in the mathematical model. “Horray for Pythagoras and trigonometry!”

My first precise cutting stencil for pyramid panels

Given that I had created a design model that was accurate to a 1mm after ‘refreshing’ my stale trigonometry and Pythagorean theory, I thought that I had better do justice to all this by improving my pannel cutting consistency.

I made a welded hard stainless steel pattern piece that allowed me to precisely cut all the major pyramid panels from one pattern piece. The metal pattern allowed me to run a craft knife along the edge of the pattern. The process used the A or the B side to cut out the panels with the straight grain either along the corner ridgelines or along the mid panel joins to facilitate the straight to bias-cut seam forming. The experience with the pattern has given me fresh ideas on an easy and precise cutting method for the real tent panels with my new hot cutter. “So, good tinkering time is never really wasted time.”

The plan for my first pyramid tent with a vestibule

The tent will be designed for both terrestrial and deep snow camping, high and low pitching and with or without bell walls. The tent will have the following general specifications:

• Base width 300cm (the maximum width that my polyester umbrella fabric will allow without panel joins),
• Generously sleep 3 people, with internal gear storage, with a central wood stick heater stove or 4 people (at a squeeze with a permanent stove) and ample wet gear drying draining space.
• Height 200cm
• Vestibule entry height 147cm (It can be 200cm in good weather and for star gazing or closed down progressively for storms and for a tortured crawl in entry).
• Vestibule maximum netted and vented area ~0.5 square m (Can be restricted by covering from inside with tent fabric).
• The polyester fabric will be a rather heavy 58gsm, but it’s zero wet stretching, condensation clearing properties and fast drying should offset this extra fabric weight. I expect that the packed weight on cold mornings will be no more than an equivalent soggy wet silnylon tent.
• Fabric weight 1064g (compared with 938g for a pure pyramid of the same size, only 13% heavier)*

Note* The fabric weight does not include seam allowances, netting, zippers and guy cords etc. and is calculated on my rather heavy 58gsm polyester fabric. The weight per person would be 355g for three sleeping places (terrestrial camping with bell walls deployed with room for a tent stove) or 266g for four sleeping places (snow camping with excavation and room for a tent stove).

First pitching

I had waited for ages for a special double slidder zipper to arrive to finish off the ridge opening of the tent and so resorted to using a single slider one in frustration. “You know how it goes the next day the zipper arrived in the mail and there was a lot of unpicking to do. I find it takes much longer to unpick a zipper than to sew it in.”

After replacing the zipper, our winter arrived with days of rain and wet grass (and luckily some good early snowfalls), so I did not wish to take the tent out for its inaugural pitching under those conditions. “Silly since that is what it was made for.” It also gave me an excuse to procrastinate a little longer.

As usual with my innovations, I have a little trepidation when it comes to putting my creations to their first real test. Much more difficult than just dreaming about success. A sunny day came at last. The grass dried, the pegs went in easily and luckily, the tent pitched well.

I was very happy with the doorway height as it was very easy to duck in and out. Even the doorway flap can be pulled out to form another protective awning.

The vestibule made the entry area very spacious and it would be protected from falling rain and snow in bad weather while moving in and out of the tent. This is a real contrast with the entry to a pyramid tent that exposes the tent to the elements. Similarly, I think the vertical vestibule window or part of the window will be quite functional during bad weather. Being able to open and close the window cover from the inside of the tent will be a blessing when the weather conditions change during the night while sleeping.

My wait for the double slider zipper and the replacement of the other one was well worth the extra effort. For the first time, I could open up the roof of my tent to be able to gaze through the skylight at the stars from my bed. The opening would also be ideal for providing extra ventilation under suitable weather and insect conditions and can also be regulated or closed easily from inside the tent.

Three or four sleeping mat positions

This little video tour of the vestibule pyramid shows there are three generous potential sleeping mat positions with a tent stove or four without the stove deployed.

Bell wall and storm pitching options

I have not yet added the required tabs for the snow/bug skirt or those that allow the tent to be pitched with a bell wall. I like to first pitch the tent to determine the optimum location of these extra tabs that luckily do not need to bear a heavy load.

It is a task that will usually go wrong if I simply rely on theoretical considerations while searching through a ‘sea of confusing fabric’ in front of the sewing machine. The task is made more complex than it may seem, as the skirt is designed to work as an external skirt to be covered with snow or an internal skirt for terrestrial camping. Luckily, it is simple and intuitive to mark out the tab locations when the tent is pitched. The task has been started… more to come.

[Add a photo of the tabs used to pitch the tent with a bell wall]

[Add a photo of the tent pitch with a bell wall]

[Add a photo of the tent pitch low in storm mode]

Conclusion to date

This pyramid with a vestibule entry has 13% wider sides and is 13% higher than my previous breathing polyester pyramid tent from which it was modelled. However, these apparently small linear increases belie the massive increases that struck me as I pitched the tent for the first time. “Although the photo can not show it, I think I can confidently say that the increased size (that the 1,500mm fabric width easily allowed) and the addition of the vestibule have achieved my goal of a winter palace for three or four people and comfortable protected winter entry.” The tent canopy with; universal stove jack, peg-out tie-out tabs & guy-out cords attached weighs 1,500g.

The floor area increased by 27% and the square shape means that most of the area will be useable. More particularly, with snow excavation, the whole area will be useable with this design that allows the bell wall to be pitched in a pyramid configuration.

Similarly, the volume of the tent is increased by 43% without accounting for the extra volume of the vestibule. The vestibule adds even more volume, but more importantly, it facilitates easy entry and exit in bad weather with less risk of wetting the tent contents with water and snow. When coupled with the extra tent height, it vastly improves head clearance.

Half of the triangular vertical vestibule wall can be used as a simple and functional doorway while the other half can be pegged down, leaving a vertical face with an easily adjusted netted ventilation window.

I expect that the space below the vestibule ridge line will become a valuable area for the formation of snow steps to access an excavated snow pit. It also should provide a space for removing wet or snowy clothing and provide an ideal location for draining/drying lines under the ridge. The jackets etc can harmlessly drip onto the floorless entrance area.

The spreadshit model that I used to compute the tent panel dimensions will allow the vestibule height to be set lower for a more storm-worthy tent shape. However, the current height of 1,500mm is a very nice compromise between comfort and storm worthiness.

The provision of peg-out and tie-out tabs that will allow the tent to be pitched 300mm lower (without the bell wall) will go some way for storm pitching. I also have a plan to be able, in desperation, to additionally temporarily lower the vestibule height for further storm stability. More on that later…..

This large pyramid tent with a vestibule will have spacious sleeping spaces for 3 people with a permanently set up tent heating/cooking stove and ample room for gear storage on either end of each sleeping mat. The capacity would increase to four people when the stove is removed for sleeping. The netted vertical window should aid ventilation in wet weather. The opened ridge zipper should provide strong ventilation when weather and insects permit. Being able to look at the night sky and stars will be a bonus extra.

Lastly, the large volume of the tent indicates to me that I should get cracking on my big brother version of my KISS hot tent stove that will utilize the 60mm stove jack that is already fitted to the tent and provide more heat and more cooking space for such a tent.

More to come….

Tim

Addendum

I am the first to admit that making a backpacking tent from cheap polyester ‘umbrella’ fabric that is not waterproof was rather radical. “Some have used less kind words such as stupid.” However, I assure you that my polyester tents that have minimal condensation problems are actually much drier than my equivalent tents made from waterproof silnylon. So for the sake of those sceptics, here is the result of my simple test of the hydraulic water head (HH) test of my silnylon tent fabric. It failed with about 200-300mm of HH.

Here is a little video that may be a little more convincing. I think it just goes to show that a high HH test is probably good for creating condensation problems within a tent, but is not critical for shedding rain and snow. I will post a similar test on the polyester fabric when time permits.

OTHER POST FOR PYRAMID TENT FANS

A large downdraft tent stove for a pyramid tent

DIY breathing polyester tent for backpacking- Beat the dreaded condensation problem

Pyramid tent design- A spreadsheet model

Polyester ageing- About as interesting as paint drying

DIY silicone seam sealer- Getting a long pot-life

Hexagonal tent design- A spreadsheet model

Tie out tabs for pyramid tents- Keeping DIY tabs cheap, small, simple, strong and light

Square pyramid tent pitching- Getting the square pitch right every time

Pyramid tent patterns- A modular DIY system