Reviews > Shelters > Tarps and Bivys > Integral Designs SilDome tarp > Test Report by Andre Corterier

Integral Designs SilDome Tarp

Test Report by André Corterier
Initial Report 18 July 2008
Field Report 06 October 2008

Personal Biographical Information:
Name: André Corterier
Gender: M
Age: 36
Height: 1.85 m (6 ft 1 in)
Weight: 80 kg (175 lb)
Email: andreDOTcorterierATfreenetDOTde
Home: Bonn, Germany

Backpacking Background:
I have started out with backpacking slowly – single-day 24 km (15 mi) jaunts by myself or even shorter hikes in the company of my little daughter. I am getting started on longer hikes, as a lightweight packer and hammock or tarp camper. I’ve been upgrading my old gear and am now carrying a dry FSO weight (everything carried From the Skin Out except food, fuel and water) of less than 9 kg (20 lb) for three-season camping.

Year of manufacture: 2008 ?
Manufacturer: Integral Designs (Canada)
URL: http://www.integraldesigns.com/
MSRP: 200.00 USD

"The Sil Dome is a minimalist tarp shelter that utilizes a single 12 ft [3.66 m] shock corded Easton .340 [8.64 mm] nanolite pole to provide its parabolic shape and allow the catenary cut 1.1 oz Silicone impregnated nylon to be tightly set up in a variety of configurations. It can be set up as an elevated dome day shelter, a ground level two-person sleep shelter with side ventilation or rolled back into an open-fronted awning wind shelter.
Interior length: 8 ft [2.44 m] Interior width: 5 ft [1.52 m]
1 lb 10 oz (740g) including pole
wt excludes 2.2 mil cord + 4 stakes (4 oz)
Supplied with 2.2 mil cord and 4 - 6" Easton nano stakes (4 oz, 115 g)"

measured weights:
tarp: 485 g (17.11 oz) - before seam sealing
pole: 166 g (5.86 oz)
4 stakes: 38 g (1.34 oz)
4 cords: 44 g (1.55 oz)
large sack: 14 g (0.49 oz)
small sack: 12 g (0.42 oz)

total weight as delivered (including stakes and bag, minus seam sealant): 764 g (26.95 oz or 1 lb 10.95 oz)
Note: The weights do not add up precisely to the total amount, I assume my digital gram scale rounded a few times.

Introduction:
The SilDome, when set up, looks like a single-hoop tunnel tent from the outside. But it doesn't have a floor, or interior mosquito netting, so it's really a tent-shaped tarp. It's made from the now becoming ubiquitous siliconized 1.1-oz ripstop nylon often referred to as "Silnylon". It features a tunnel seam for the flexible pole, 8 webbing loops around the bottom edge for staking down, three webbing loops on top of the pole ridge and an adjustable inside strip of webbing to adjust the width of the tent.

The package came with 4 stakes, 6 in (15 cm) in length. That's pretty short for a stake, I thought - but it was sufficient to set up the tarp for the first two times (practice). Also included were four small rolls of black cord. I'm at a loss trying to figure out how I could possibly use four cords at the same time - I assume I'll need at least one stake staked through a bottom loop no matter how I set this baby up. We'll see. Four stakes also didn't strike me as a lot. Again, we'll see how many I will seem to need when using it in the field.

Unpacking:
The SilDome comes in a long, slender silnylon bag. Upon opening it, I first withdrew the folded pole. It's a rather slender, hollow pole made from flexible aluminum with shock cord running through it which keeps the segments together (and assists in putting them together). Next I took out the tarp, which was neatly folded though no creases remained in the silnylon once I shook it out (which also means that I'll never be able to put it back together like that). And then there was a small black bag which contained four small stakes, four loops of cord and a tube of silicone seam sealant.

The latter stumped me for a moment. Neither the website nor the accompanying tag mention seam sealing in any way, shape or form. But I note that the tarp does have seams and they do not appear to have been taped or in any other way waterproofed, so I guess this will be up to me. It seems strange that this isn't even mentioned on the accompanying card.

Setting Up:
The SilDome was easy to set up. I shook out the tarp, then quickly assembled the pole and slid it through the tunnel on the inside of the tarp. The pole ends in metal points which easily fit into the metal grommets in the bottom webbing band. As the bottom band is of a shorter length than the pole, this forces the pole to flex into a flattened semi-circle. This semi-circle initially remained on the ground, as nothing held it up. Then I staked one end of the tarp down and pulled on the other end and - presto, instant shelter. All it took was to stake down the other end and I had a self-supporting shelter. At this point, I was still left with two stakes and four rolls of cord (and a tube of seam sealant) that I hadn't even used yet.

However, the tarp initially didn't seem to conform to a nice, tent-like shape. While the tarp went down close to the ground at the end points which were staked down and the side points where the pole stuck in the bottom webbing band, the side walls of the tarp seemed to curve upward a little between those points, creating what looked like more than adequate ventilation (and a potential ingress for rain).

Seeing that the tarp is described as having an interior length of 8 ft (2.44 m) and width of 5 ft (1.52 m), I shortened the bottom webbing strap (which is length-adjustable via a ladderlock buckle) to about 5 ft or so (1.5 m), which required relocating one stake and moving it a little closer. The resultant structure looked odd, and the problem I described earlier seemed aggravated: While the staked lengthwise end points were now a little closer to the pole, this was due to the fact that the pole now had a higher central height which therefore also increased the upward curvature of the tarp's bottom hem.

The reason for this soon became apparent. The tarp has a catenary cut. In layman's terms (I'm a layman) this means it's cut to resemble the curve a rope would describe when fixed to one spot on the ground at one end and another spot higher up at the other end and left to hang by itself. This creates an equal distribution of load along the rope. Which, I guess, is why such a shape is considered beneficial for tarps, which may be subject to wind loads. The tarp appears cut to describe catenary curves from the top of the pole to the bottom of the tarp. This creates a three-dimensional structure, and it works out only if the pole is fixed at the correct height.

It was easily apparent that the pole's foot ends needed to be further apart, and so I extended the webbing strap, bit by bit, until I found a pitch where the sides of the tarp followed the ground. Obviously, this was how the tarp was meant to be set up. Easy enough, too - now that I had the bottom webbing strap adjusted just so, it would immediately form an enclosed shelter with only two stakes. Neat.

Dimensions:
The surprise was that, although this was clearly how the tarp was meant to be set up, it was a lot broader and longer on the ground than I had anticipated due to the measurements given on the accompanying tag. From stake to stake, it was just over 4 m (just over 13 ft) long, and about 2.8 m (over 9 ft) broad along the pole.

Of course, much of that footprint does not have a useable tarp height over it - catenary curves not only equalize loads, they minimize space. The *useful* internal space seemed to be about 1.5 m by 2.4 m or 5 ft by 8 ft - just what it says on the tag (and the web). Yay! So I guess I set it up right after all. I did find this slightly confusing but the tarp's shape speaks for itself.

Trying Out:
I tried getting into and out of the SilDome, lying down in it etc. None of this was a problem. The waterproof zipper works. It's a dual zipper, so I can open a small (or large) gap at the top of the zipper rather than just moving the zipper up and down. I don't know (yet) why I might want to do that, but the possibility is there. My 6-year old daughter was quite taken with this. Operating the zipper takes two hands, unless one of the loops at the bottom of the zipper is staked down. Bang, there went the third stake and now the zipper could be operated with one hand. Nice.

The room inside is ample for myself and more gear than I care to carry, thank you. Another grown up should also find space. I'm pretty sure that it'll fit me and both my six (nearly seven) year old daughter and my two-and-a-half year old daughter. I'll be sure to try this out in the field at least once (my older daughter now prefers to sleep in her own hammock).

It started raining shortly after I set up the tarp (both times). The water beaded up on the silnylon and then ran down. The seams did not leak any water during a half hour rain shower, which was good to know. There was some wind the second time I set it up as well, and while the flexible pole moved with the wind a little, it appeared stable enough with just two stakes.

Initial Summary:
Well, it's a pretty lightweight solution for the amount of room it creates. I'll be interested to find out whether I'll really make do with two (or three) stakes or feel the need to carry more. I'll be carrying the full set (and possibly two extras) when trying it out, but will try to find the workable minimum.

Field Experience:
I've set up the SilDome near the Rhine River close to home (elevation about 100 m / 330 ft), in the Eifel hills (at about 350 m / 1150 ft) and for two nights in the Netherlands (about 40 m / 150 ft). Temperatures, precipitation and wind speeds were too boring to have been properly recorded vis-à-vis the first two events. For the two nights in the Netherlands, temps bottomed out around 4 C (38 F), with quite a bit of rain and serious winds the second night.

Setup:
I've set up and broken down the tarp and made adjustments to it in broad daylight and at night with a cast-over sky, without the help of a headlamp (don't ask). It was easy to do - there's nothing finicky about this tarp that would make it hard. Possibly the hardest thing to do is find the entrance of the fabric "tunnel" which accepts the flexible pole (and to remember that it should be on the inside of the tarp). That's all. And that's nice.

Space:
Not so good news on this one. While I've found the tarp to provide lots of storage room for gear when it's just me sleeping in it and the conditions are easy, which means I sleep in a not-so-thick sleeping bag on a thin pad, colder weather has changed my view on this. In the Netherlands, I was sleeping on my Down Air Mat, at about 7 cm (3 in) of thickness, in a puffy down bag (rated to -7 C /20 F by its manufacturer). This put the top of my bag easily 10 cm (4 in) or more closer to the sloping ceiling of the SilDome, which meant that once I started moving about a little in my sleep, the head and foot ends of my sleeping bag spent a good portion of the night in contact with the ceiling. As I also had a condensation issue (see below), I was glad for the water resistant fabric at the head and foot ends of my bag.

Of course, this was with the sidewalls of the tarp staked down to the very ground. I hardly felt any wind inside the tarp, even though it was quite windy and the tarp was set up in an exposed place on low grass. For the second night, I decided to pull the strap which regulates the width of the tarp a little closer, in order to create more headroom. This worked. As the walls of the tarp slope down to the ground in a curve and that curve still has to end up at or very near to the ground, an increase in the center pole's height does not translate in an equal increase of ceiling height across the tarp. But I managed to change the setup so that I could sleep without (or at least only rarely) contacting the tarp even on my thick pad and in my puffy bag. However, I suppose two people would find the tarp a squeeze under such conditions.

Limiting the width of the tarp like that not only increases the center height, it also means that the lower hem of the tarp no longer follows the ground precisely, but rather curves up a little between the stake out points. I managed to find a compromise configuration in which I was okay with the head height without going into an all-out stork-legged shape. I was actually quite happy with it having ventilation slits along the bottom, though I staked it down as much as I could on the windward side.

Condensation:
The first night in the Netherlands was condensation prone: I set up on wet grass, there was some fog and sprinkly rain through the night. I had the tarp staked down so it hugged the ground and the door closed. Now that I'm laying the facts out like that, I guess I shouldn't have been surprised to find a lot of condensation after spending a night under an effective cheese cover. Yet, I was surprised to find drops of moisture dropping onto my face at night.

The second night fared much better in this regard. We were still camped in the same spot and I changed the configuration as described above, which created ventilation openings around the bottom rim of the tarp (which I - successfully - tried to minimize on the windward side). I also used the dual zipper to create a small opening at the top of the zipper in order to create a vent there without letting in too much rain. This seemed to have worked very well (maybe that's why it's a dual zipper). Even though there was a lot of wind (calling it a storm would not be an overstatement) very few drops were blown inside and there was very little condensation the next day.

Wind Resistance:
While I wasn't rained on during the second night, I did wake up when the sidewall of the tarp hit me in the face. The tarp created the strangest three-dimensional contortions under the influence of severe wind pressure. The pole flexed considerably as well, forming the outline of half an egg lying on its side or a rectangle with rounded corners, but each time springing back into its usual shape. This allowed the sides of the tarp considerable freedom of movement. I decided to go out at night and guy out the side of the pole sleeve which faced the wind. This was easily accomplished with the provided guy line and not hard to do even at night, without a lamp. The attachment points at the tarp are easy to pick out at night.

This markedly improved the wind resistance of the tarp. The pole flexed very little thereafter. The sides of the tarp still flexed and bowed, but it rarely contacted me inside and certainly didn't slap me again. While this was somewhat noisy, it wasn't all that noticeable over the general sound of the wind and rain. While I was lying there in the tarp, listening to the general ruckus, I was making mental notes of negative things to report in my test report until I fell asleep again. The next morning it turns out that about half an hour after my daughter vacated her hammock because she was getting a bit scared, the wind tore the rain fly off her (name brand) hammock. So... it appears that it really was a LOT of wind the tarp was exposed to, and I have to say I felt very little of it inside the tarp. So I'm happy with that.

Stakes:
The stakes went into the ground easily each time (though I have to admit it wasn't challenging ground, stake-wise). They held fast and did a good job of keeping the tarp in place. In easy conditions, I found two stakes to be sufficient (three if I want to open the door with one hand). In the windiest night, I used five stakes on the windward side (four on the hem of the tarp and one for the guyline) and another one on the lee side. This makes me think that I would generally want to carry six ("always have a spare").

Reviews > Shelters > Tarps and Bivys > Integral Designs SilDome tarp > Test Report by Andre Corterier