Another Roof Collapsed

[devildog1]

Just listened to Local News and were the barn roof collapsed last week killing around 70 or so dairy cows. Another roof at same farm caved in, poor farmer, having to deal with all the other things thrown at him now another roof at his farm.Whew just finished cleaning off valleys and edges of my roof because weatherman said more snow tonight, I believe lake effect snow from Lake Ontario. That stuff is quite heavy up there, just wondering has anyone figured out roughly how much 28" to 30" of ice and snow weigh on roof?
DevilDog

 

[JDGreenGrass]

Just listened to Local News and were the barn roof collapsed last week killing around 70 or so dairy cows. Another roof at same farm caved in, poor farmer, having to deal with all the other things thrown at him now another roof at his farm.Whew just finished cleaning off valleys and edges of my roof because weatherman said more snow tonight, I believe lake effect snow from Lake Ontario. That stuff is quite heavy up there, just wondering has anyone figured out roughly how much 28" to 30" of ice and snow weigh on roof?
DevilDog

I would guess around 70 or 80 pounds per square foot. Maybe more.

 

[Gizmo2]

I would guess around 70 or 80 pounds per square foot. Maybe more.

70 to 80lbs?
http://www.flagstaff.az.gov/DocumentView.aspx?DID=12809

 

[herringchoker]

Gizmo - thanks for the great link.:thumbsup: I have a good 3 feet of snow on my roof now, but my design snow load is 77 lb./sq.ft. I was concerned about how much 3 feet of snow weighs, so this morning I cut out a 12" x 12" x 12" cube of snow, packed it in a bucket and weighed it - about 10 lbs. (which is about mid-range in the Arkansas link you provided). So I have about 30psf on my roof now, but if it gets rain-soaked I may be approaching my roof design limit. Interesting!

 

[Gizmo2]

herringchoker,
I guess you know I was thinking about the same thing. That's why I had the link readily available. I could not seem to find a site from NY but figure snow is snow. Can't be to safe.

 

[Carykong]

Where there any details on the type of barn,age,roof slope?

 

[JB4310]

70 to 80lbs?
http://www.flagstaff.az.gov/DocumentView.aspx?DID=12809

He's talking about 2.5 cubic feet per sq ft so it's right in the range of heavy wet snow and ice from the chart you linked to; We've got all kinds of buildings collapsing around here, we've had 6+ feet of snow in just over a month, it's compressed down to 20-30 inches.

Doesn't look like much but I can tell you this aint no 10 pounds per cubic ft snow, closer to 40 or 50 Pounds PCF, Just ask my Back
So that estimate is probably not that far off and could be under estimate, buildings don't fall down around here with 40-50 PSF on them.

Driving around the last few days I've seen several cranes working with a small army of man power, removing snow from large roofs like Home Depot and Walmart, both have been closed for a few days now for evidence of structural problems/fear of collapse. These are record setting/code changing conditions.

JB.

 

[First one]

Originally Posted by devildog1 View Post
Just listened to Local News and were the barn roof collapsed last week killing around 70 or so dairy cows. Another roof at same farm caved in, poor farmer, having to deal with all the other things thrown at him now another roof at his farm.Whew just finished cleaning off valleys and edges of my roof because weatherman said more snow tonight, I believe lake effect snow from Lake Ontario. That stuff is quite heavy up there, just wondering has anyone figured out roughly how much 28" to 30" of ice and snow weigh on roof?

How do you get over something like that?
And then to happen again , I bet he just felt like taking a walk out behind the barn and throwing in the towel.
My hats off to him and his family.

I just cleaned off my glass greenhouse(17x30) it looked to be about 1.5- 2' . I just touched it with the roof rake and the weight of the snow sliding down took out one of my roof pans (about $60.00) The only way to get it off was to try and shovel it off a little at a time. After about a couple of hour I finally got it. The plastic hoop house I have, didn't look much better about the same amount on that as well. What kept either one of these from collapsing I don't know.

 

[JDGreenGrass]

I would guess around 70 or 80 pounds per square foot. Maybe more.

I remember now....When my garage collapsed back in '08 the insurance adjuster came to my place. He told me many of the lost buildings had 60 to 70 lbs/sq. ft.

He was actually a temp add on. There were soo many buildings down that the local adjusters couldn't keep up.

So, ya...my estimate was a bit high.

By the way....my garage had patches of snow and ice build up of 3' and 4' feet.

If you do not keep up with clearing your roofs each storm, it can get away from you in a hurry. I nearly lost my truck when the roof and walls blew out. For some odd reason I went into work on a Sunday morning.??....Came home and my garage was down.!!.......

 

[Gizmo2]

JDGreenGrass,
Gives me cold chills just looking at your picture and trying to just imagine.........

 

[blackie65]

after reading several post like this one. I got nervous. What I did was pull my drop down stairs to the attic and left it open for a day or two. That really helped and cleared quite a bit of the snow. I am in the Midwest and had probably 4-6" up there with a little drifting in the valley's. May not help everywhere but it put my mind at ease.

 

[herringchoker]

herringchoker,
I guess you know I was thinking about the same thing. That's why I had the link readily available. I could not seem to find a site from NY but figure snow is snow. Can't be to safe.

You're right there - snow is snow. I got up on the roof today and started shovelling, but I took a sample with the Arkansas coffee can method before I started just to see if it compared with my 12"x12"x12" cube. Still waiting for the bucket of snow to melt for the results on that. I'm more worried about a rainstorm coming along and wetting down what's up there now.
I got about 1/3 of the roof cleared, now I,m beat. More to do tomorrow, and I've got to knock down the pile in front of my south windows - that's my #1 heat source.

 

[Gizmo2]

You're right there - snow is snow. I got up on the roof today and started shovelling, but I took a sample with the Arkansas coffee can method before I started just to see if it compared with my 12"x12"x12" cube. Still waiting for the bucket of snow to melt for the results on that. I'm more worried about a rainstorm coming along and wetting down what's up there now.
I got about 1/3 of the roof cleared, now I,m beat. More to do tomorrow, and I've got to knock down the pile in front of my south windows - that's my #1 heat source.

All I can say is WOW! I'm tired just looking at the pictures. I have shoveled a few roofs in my life but none with quite that much snow.

 

[Carykong]

I built my barn with a roof slope that has a 8' run and a 10' height. Any accumulation just slides off.

 

[JB4310]

Gizmo - thanks for the great link. I have a good 3 feet of snow on my roof now, but my design snow load is 77 lb./sq.ft. I was concerned about how much 3 feet of snow weighs, so this morning I cut out a 12" x 12" x 12" cube of snow, packed it in a bucket and weighed it - about 10 lbs. (which is about mid-range in the Arkansas link you provided). So I have about 30psf on my roof now, but if it gets rain-soaked I may be approaching my roof design limit. Interesting!

I found out today that our roofs are supposed to built to 30 psf, I'm sure that will go up after this year.

You're right there - snow is snow. I got up on the roof today and started shoveling, but I took a sample with the Arkansas coffee can method before I started just to see if it compared with my 12"x12"x12" cube. Still waiting for the bucket of snow to melt for the results on that. I'm more worried about a rainstorm coming along and wetting down what's up there now.I got about 1/3 of the roof cleared, now I'm beat. More to do tomorrow, and I've got to knock down the pile in front of my south windows - that's my #1 heat source.

WOW is right, I've seen snow that deep on a few roofs but only in isolated pocket areas not across the whole roof. I see why your standard is 77psf, if that much snow ever got saturated, better sleep with 1 ear open to listen for the creaking. I'm sure living in that climate you are well aware but I'll just mention anyway, to be careful not to block any vents like dryer or heater exhaust. for the threat of CO poisoning.

Our town checked a couple of public buildings roofs and they said it was right at 30 psf with around 20-24 inches of snow, I didn't weigh anything but am a pretty good estimator out of necessity and that does not seem to be consistent with what I've been working on. I'm certain on some of the roofs I've removed snow from, the snow was much heavier than that, one was so wet it was only maybe 12 inches deep but you could not pick up a shovel full of it.

Stay safe, JB.

 

[herringchoker]

The snow in my Arkansas coffee can test has melted and the depth has been measured - 8" of water, which works out to a snow load of 41.6 psf. This is higher than my estimate based on my 12" snow cube, I am sure because my cube was higher up in the pack and did not account for the more densely packed snow at the bottom. Back at it again today, before there's ever a chance of that getting rain-soaked.

 

[Gizmo2]

Back at it again today, before there's ever a chance of that getting rain-soaked.

I'd really like to say I'd give you a hand but the distance thing makes it near impossible. Be safe!

 

[eepete]

Here's my collapsed building tale of woe...

But compared to the dairy farmer I got out lucky. Very sad to hear about all the problems people are having.

http://www.tractorbynet.com/forums/john-deere-owning-operating/162706-new-jd4520-cab-destroyed.html

Pete

 

[herringchoker]

[



WOW is right, I've seen snow that deep on a few roofs but only in isolated pocket areas not across the whole roof. I see why your standard is 77psf, if that much snow ever got saturated, better sleep with 1 ear open to listen for the creaking. I'm sure living in that climate you are well aware but I'll just mention anyway, to be careful not to block any vents like dryer or heater exhaust. for the threat of CO poisoning.

Stay safe, JB.

I built this house myself in 1981 and it's based on the 1980 National Building Code of Canada. The roof design snow load is equal to the ground snow load for this locality multiplied by a factor that accounts for the roof slope. Our ground snow load here (at least in 1980) was 75psf.

I keep an eye on a bedroom door that has a rather tight tolerance with the top of the jamb (I'm not much of a carpenter now, I was even worse back then). If it starts to scrape a little more than usual, that probably means some deflection in the roof trusses above it. It did and now with the snow gone it is less sticky (1/64" or less deflection).

Both plumbing vent stacks were covered, but had melted snow caves around them. The wind turbine ventilator was also covered, but that's no big deal since the inlet grills are closed off for the winter. The chimney for the wood furnace was high and dry.

I heard on the radio that we are within a few inches of setting a record for ground snow cover. The current record is 161 cm. (63"), and that was dumped on us in two storms over five days in 1992.

I'm about 70% done clearing now, hope to finish tomorrow. The deepest I've encountered is 42", however it's only about 16" at the peak. I figure I've already shovelled close to 16 tons off the roof. Next job is the garage.

 

[herringchoker]

I'd really like to say I'd give you a hand but the distance thing makes it near impossible. Be safe!

Thanks anyway, I appreciate the thought! :thumbsup: