Any challenges of building an 11' vs. 9' that I should know?

[Banff Martin]

Good morning!

I'm about to commit to building my first 11' igloo, and will do so right next to my mutant 8.5' igloo. I think it is inevitable that a tunnel will be cut to connect the igloos through the pads. I've yet to decide on if the 11' will have its own entrance; it would be neat to only have the single entrance to both igloos, but I have to wonder about safety issues as a wide variety of people are using the 8.5' igloo? (The 11' will have 1-2 air holes)

Is there anything I should know about building the 11' model before starting?

I'll be finishing the pad tonight so it will be solid to build on tomorrow, and am planning on it being 15' across (and about 2' deep) to ensure it is large enough all the way around it. I'd think 14'6" would be what is needed to have a 1' ledge around the outside, but the more the better for building. If I've help, they will all be new to Icebox igloo building.

The snow will be new from today & tonight, in temps ranging from -10 to -25 C. I could delay by a week for warmer temps, but if built by end of Sunday the overnight low of -27C should turn it to stone and reduce sagging?

To improve snow condition after gathering, I'm thinking to stir the snow in my large construction-size bucket before loading into the form. My available tools are a large scoop-bucket shovel, (slightly heavy) metal shovel, large bucket, and 4L milk jugs. I normally use the latter (bottoms cut off, bottom edges reinforced with popsickle sticks & duct tape) on the final blocks on the igloo but think I may use them earlier vs. the heavy shovel to conserve energy.

Thanks for any suggestions!

[Igloo Ed]

The difference in the 11 ft., it's a lot of snow and takes a long shovel handle to get the snow to the top.
The roof is rather large/flat and quite a bit of time is spent packing up high, a milk crate for the packer to stand on is nice.
I guess one thing that is nice is that the form is filled full, it makes it feel like you're getting something done when you fill it all the way.
Two entrances will result in a cross breeze or draft. I'd consider putting the door in the 11 ft and have the smaller igloo as a second room.
If the snow is cold and fresh, there is only so much you can do to compact the snow. It'll still sag more when it warms up than one built of snow that did warm up. The 11 ft. is pushing the support offered by the thin 8 inch walls.
With the igloos being so perfectly shaped, they do tend to get some respect.

[Banff Martin]

I will be trying to get builders for next weekend. =)

I do not think we will actually use shovels for the higher levels; I think my modified milk jugs may be kinder to the shoulders. We will see how things go...perhaps I will rig up something else as well. I suppose I am thinking of the weight of my metal shovel that is leading me to think that way. I have not found other good shovels to replace it thus far.

As the 8.5 foot mutant is already built with a door, and I feel the new one should have one for safety, a breeze may be inevitable. Perhaps I will have the tunnel enter into the 11 foot below the level of the floor; the new pad is higher than the old and this may be enough to reduce wind. Or I could hang plastic at each end of the tunnel.

We got a few inches of new snow this past weekend. While it did go down to -26C it will be no warmer than -3C as a daytime high through the week. It may be this temp on the weekend for building as well.

If I have enough help, I may ask them to stir snow in the big Rubbermaid bucket before loading it into the form to improve its condition. Is there anything else to be done to improve the condition of the snow? We will be gathering the snow from at least 30 feet away.

Thanks Ed!

[Igloo Ed]

I think waiting a week for the snow to get older will make the biggest difference in snow that won't compress.
Typically, I sweep the snow over to the igloo, even when it gets close to 30 ft away. I can sweep/throw it about ten ft. each time. After sweeping it three times, it is about as condensed as it can get.
I see the problem with the shovel though. I wouldn't want to be sweeping with a heavy shovel.
Walking on the snow condenses the snow too. Maybe you could stomp in the bucket/tub.