How long do igloos stand before sagging?

[fish]

Hi,
Provided temperatures are constantly below freezing (at least -10C), and an igloo is inhabited every night; How long could an igloo stand before noticeably sagging?

Scenario #2: Same temperatures, however lets say the igloo is inhabited 2 nights of every week (friday/saturday nights), would this change the stand time?

Cheers!

Fish

[Igloo Ed]

Hi,
Provided temperatures are constantly below freezing (at least -10C), and an igloo is inhabited every night; How long could an igloo stand before noticeably sagging?
Scenario #2: Same temperatures, however lets say the igloo is inhabited 2 nights of every week (friday/saturday nights), would this change the stand time?
Fish

After staying in your igloo and then leaving, the walls form a thin layer of ice and this pretty much stops an igloo from sagging. Living it all the time would make it sag faster but the foundation and the type of snow the igloo is built with makes a bigger difference in how fast they sag.
The longest I have stayed in one igloo is five consecutive nights and there was no noticeable sag but the walls were melting and getting thinner. Because of the walls getting thinner, I think one could only stay in an igloo built of powder/light snow for a couple weeks. Old icy snow might make it a month or more. Hard to say though as there are so many variables with the type of snow, the foundation, the sunlight vs. shade and just how correct the shape of the igloo is and it only takes one of those variables to be off and it'll sag much faster.
I did a spring trip a few years back where I built the igloo of cold/fresh powder and it was heavenly to build with. We stayed the night and went for a ski the next day to come back to our igloo around 4:00 pm to find a large disc had sagged inwards about 1 1/2 ft. and 3 ft. in diameter. It had sagged so fast that there was a crack on the inside. We patched the sag from the outside and then trimmed the inside off again. It had caused the igloo to get a little shorter but I checked the igloo a week later and it was still fine. The patch was made with wet spring snow as the cold powder had received sunlight all day.

[Climbingaggie04]

I've been living in a 10 foot igloo for a bit over a month, it was made with very granular sugar snow and we didn't adjust the pole correctly so it is not a catenary shape, it's more dome shaped. It has sagged enough to notice, but not enough to be a problem yet, and it had to deal with 5 days of highs in the 40-45 degree's F range. So generally I'd agree with you ED. I started work on a second Igloo today, it's an 8 footer and I'm working the pole properly this time and I packed the foundation from the bottom up so I'm hoping that it will last 6 weeks time will tell though.

[fish]

I've been living in a 10 foot igloo for a bit over a month, it was made with very granular sugar snow and we didn't adjust the pole correctly so it is not a catenary shape, it's more dome shaped. It has sagged enough to notice, but not enough to be a problem yet, and it had to deal with 5 days of highs in the 40-45 degree's F range. So generally I'd agree with you ED. I started work on a second Igloo today, it's an 8 footer and I'm working the pole properly this time and I packed the foundation from the bottom up so I'm hoping that it will last 6 weeks time will tell though.

It would be very interesting if you could come back and post an update as to how long your igloos lasted!

Cheers,

David

[kealia]

I built a nice 8 foot igloo in my front yard the second week of December. I used fresh powder snow at -15 degrees. The building was difficult, but it ended up as a very nice 'gloo!

We spent a lot of time in it, and it developed a thin layer of ice on the inside. As more snow fell in December and January the walls grew thicker and thicker. Eventually the snow was like cement.

Although it did seem to diminish in size slightly, it was more or less the same until last week, when an unusual low pressure system went northwest of us! Now usually these systems go south and east of us until the beginning of April. That leaves us on the north side, which is cold and snowy. Monday, Tuesday, Wednesday and part of Thursday saw constant temperatures in the upper 30's with rain! These were our first 30 degree temps since the end of November.

The igloos held out in the temps, but once the rain started..... the melting began. 24 hours later it has melted into a twisted, shrunken mass of ice and snow. It was sad. The entire neighborhood was disappointed.

We lost over 12 inches of snow in those three days. We still have eight to ten inches left, but it is pretty hard and icey. I dont' know if this will make igloos or not. We have a camping trip planned for the end of the month, and I was hoping to build and igloo and avoid the tent. We still have a good six weeks left of winter here, so maybe......

Mark in Minnesota

[Igloo Ed]

We still have a good six weeks left of winter here, so maybe......

Hopefully you get some fresh snow or you can find a big drift where the core is still snow and not ice. It'd be a job digging it out though.
Had rain a few years ago at the Mpls demo in Nov. We built the igloo from man made snow, so it was very dense, and the rains only melted a 18 inch hole through the igloo. It rained real hard, the water was nearly going over the curb in the parking lot the big tent sits on.

[Climbingaggie04]

I've been living in a 10 foot igloo for a bit over a month, it was made with very granular sugar snow and we didn't adjust the pole correctly so it is not a catenary shape, it's more dome shaped. It has sagged enough to notice, but not enough to be a problem yet, and it had to deal with 5 days of highs in the 40-45 degree's F range. So generally I'd agree with you ED. I started work on a second Igloo today, it's an 8 footer and I'm working the pole properly this time and I packed the foundation from the bottom up so I'm hoping that it will last 6 weeks time will tell though.

It would be very interesting if you could come back and post an update as to how long your igloos lasted!

Cheers,

David

David,
I've been in my 8 foot igloo since feb 5th and it's now march 13th so about 5 weeks later it's still going strong. I have had to shovel/pack snow on because where I built gets more sun than I anticipated and we've had at least 5 days of highs in the 50's! However when I first built it, I could stand fully upright in the trench and have an inch of clearance between my head and the ceiling, and I still have that inch of clearance. I do have a solid ice layer inside which has probably contributed to the stability of it but I haven't had too many problems with dripping because I managed to smooth the insides enough to where it runs down the sides. Our weather has cooled off and we've been getting more snow so I'm hopeful that my igloo will last til the end of march. Also I boot packed the foundation from the ground up, and let it settle for a day before I started building on it, which made sure that it was packed the whole way down, and gave it more than enough time to set up.
Hope that's informative, when I move out, I plan on posting the GPS coordinates of my igloos so that people can use them if they want.