A Foot of Snow Will Bend A Low Sloped or Flat Roof.

Last year a very wet foot of snow fell on Dallas for the first time. At 32°F you have the wettest snow possible. Many people called us with sags and other problems. One adjuster told me he say no structural damage from the snow and I let out a roar of a laugh. "What about all the collapsed patios and carports?" He said that that was different. I asked "how?" He said those were different. Again I asked "How?' and he gave me the blank stare.

One guy told me he kept and I on his home and the sag over his cathedral ceiling was new. The insurance said no.

A new customer has a leak on his low sloped composition roof that began last year. First the roof leaked only in harder rains and after we tried to fix the tarred up skylight, it leaked in a sprinkle. We noticed that when observing the roof from the other side that the roof looked like it had a lake on it. When standing above the roof you could not see the lake.

The roof had sagged and parts of the roof had less than the minimum magic slope of 2/12, a fall of two feet every twelve feet. In fact the surface became a collection bowl toward the center.

The adjuster saw nothing broken but bought the slope of roof and the inside damage. There was no reason to buy this slope except for the fact it was bent and he didn't pay for the unbending, reframing that is, of the section. What a dizzz. He had the gall to argue with me about the minimum roofing slope claiming the statute was 3/12. I quoted the IRC, International Residential Code (the precursor for the UBC or Uniform Building Code), the NRCA, GAF, Certainteed.... he said we could agree to disagree. I told him "No. I am right and you are wrong." The gall bladder of him.

Some of these bent and sagging roofs are starting to show more stress but the insurance companies will continue to blame defective construction methods. Funny how these methods worked until we had the first foot of snow in this epoch, and it was as wet a snow as can be. Besides, as the snow slowly melted a pool formed behind the overhangs causing more weight than the foot of wet snow. Now a small lake maybe two or three inches deep of slush and water was added to the foot of snow.

If the structure bends, the framing will never go back to where the original plane was. The result will be somewhere between 1/3 and 2/3 spring back but if you are at the minimum, you no longer are. Leave this on the roof for a week and she'll never be the same.

On top of all this, on low slope roofs the weight is placed more on the rafters and joists themselves rather than the outside walls. The steep the roof the more the load is on the walls. The less the slope, the more weight is on the middle of the roof.


Let's see how much wet snow weighs.

From Answers.com:
Ken Hellevang, from the University of North Dakota says:

"The weight of snow varies greatly. Light fluffy snow may only weigh about seven pounds per cubic foot. More average snow may weigh 15 pounds per cubic foot and drifted compacted snow may weigh 20 pounds or more.

Read more: http://wiki.answers.com/Q/How_much_does_a_cubic_foot_of_snow_weigh#ixzz1D10H8loQ

Or how about this answer from Answers.com:

That depends

It depends on how much you have!!
One shovelful of snow, for example, weighs less than the amount of snow on your driveway.
I suspect what you are really asking is not how much snow weighs but how much it weighs per cubit foot or cubic yard. Weight per unit volume is called density.
But even that is tricky with respect to snow. The density of snow varies greatly. Lightly packed powder weighs very little per cubic foot, whereas slushy, wet snow can weigh over 62 pounds per cubic foot -- about the density of water.

.

Read more: http://wiki.answers.com/Q/How_much_does_snow_weigh#ixzz1D10fRMvO

And another:

A square foot of snow does not have a weight: the depth of the snow is needed to give the weight because weight relates to the volume of snow. Even if you know the depth of the snow, say a foot, giving a cubic foot of snow, there is a wide range of possible weights because snow can vary in density depending on whether it is lightly or densely packed.

The range of density of snow compared to the density of water can vary from 100:1 (for snow that is 100 times less dense or heavy than the equivalent volume of water) to 3:1.
A more common density might be around 12:1.

Water has a mass of 1kg/L so for a cubic meter (1000L) of snow, the mass could be anything in the range of 10kg to 333kg.
Keeping that in mind, a foot of snow would be about 6.75lb to 223.82lb.
The weight of snow can not be answered based on an area of a square foot of snow: the volume is required. It also depends on the kind of snow it is. Example- packing snow will have a different weight (because of its density) than other kinds of snow.

Read more: http://wiki.answers.com/Q/How_much_does_a_square_foot_of_snow_weigh#ixzz1D11H9FVf



Are we sure that there is no possibility that this newly sagged roof, that didn't sag before the snow, could not have been damaged by the melting foot of very wet snow. If you add 620 lbs. of wet snow to the middle of the roof for every roof square, and the average roof is 35 squares, then you have 21,700 extra pounds on the roof with much of it going to the center. Any preexisting sag will now become an arroyo.

The roof I've been referring to has only 625 feet of surface area on a 2/12 pitch with no framing between the ridge and fascia. That's 3,875 lbs, almost an F-150 Ford pick up, and is if you add the melted pooling water under the snow. That is if you break it down by the foot because some areas give up weight to place it in the middle of the roof.

Remember the Metrodome!

Jon Alan Wright

Jon Wright Roofing, Siding, and Windows

1915 Peters Rd., Suite 310

Irving, TX 75061

972.251.1818 Office

214.718.3748 Cell

972.554.8090 Fax

jonwright@jonwrightroofing.com

http://jonwrightroofing.com/

Master Elite Roofer: (Scroll to the bottom)

Mumbarak Went Cheap On His Roof And He'll Dance For It

Saddam and Hosni both went cheap on their roofs and look where it got them. Saddam was executed and soon so will Hosni. Because he said he would quit after killing a few hundred more people for old times sake, he will be doing the Mussolini swing, a dance performed inverted from the end of a rope. This modern swing dance is credited with being the inspiration for hip hop dancing the world over.

Better roofs, capable of resisting whatever the local environment can throw at them, whether it be four inch hail stones or Stinger missiles, are available in every market. We use reinforced asphalt whereas the Egyptians use reinforced concrete. Sometimes we use leak protectors or better ventilation and they build theirs inside a mountain.

Despite the slight differences in techniques, the same testing logic prevails. So if you want to remain dictator of your home for more than a measly 30 years, we have a 50 year option that can keep you in control until the drool runs down your lip.

Just look how long the pyramids have lasted. They've lost track of the warranty a long time ago and their have been several property claims filed over the millennium too.

Today we have learned that all tyrants and kings, absolute rulers of their homes and homelands, should use a certified roofer with all the training and experience necessary to keep their abodes from falling into chaos.

Or they better go to Arthur Murray and practice.

Jon Alan Wright

Jon Wright Roofing, Siding, and Windows

1915 Peters Rd., Suite 310

Irving, TX 75061

972.251.1818 Office

214.718.3748 Cell

972.554.8090 Fax

jonwright@jonwrightroofing.com

http://jonwrightroofing.com/

Master Elite Roofer: (Scroll to the bottom)

Old Roofs And New Roofs In The Cold, a Rambling Blurt

Dallas seems to be defying the theory of Global Warming. Yes evolution is a theory. All are theories because the empirical proofs either has passed and only evidence remains or the theory has not been completed yet.

Dinosaurs in the past and warming in the future.

But it sure is cold, neither a proof nor disproof. Funny how the dictionary lists theory and hypothesis as antonyms for proof. They seem to be neutral and not opposite in meaning.

But it is cold and for the second year there is prolonged ice on the roofs in Dallas. Last year a foot of snow caused a lot of damage, even structural, but unless something was broken, the insurance companies denied every claim unless sued. It seems bending, bowing, and warping under weight was not covered.

Somebody needs to do something about them. A foot of wet snow can bend anything.

But it's cold and ice is on the roofs, again. Don't you think a little leak protector like Ice and Water,  WinterGuard, StormGuard, or WeatherWatch would have been a low cost investment to protect domestic tranquility?

Too late now buddy. You bought the slightly cheaper thing and now it can't do what it was supposed to do. You lost everything. Who was that preacher around 1900 who said the maxim of business is you can't get a lot for a little so if you decide to buy the cheaper thing, set some money aside to pay for what it can't do, and then you'll have enough to buy the better one?

Dallas Texas does more than get hot. Anyone outside today can blame those Packers and Steelers. They brought it with them to rub our collective noses in it. Let them live here for two years and they'll be wimpier than us, just like the other displaced Yankees who cry when it gets cold.  Don, one of our group, has decided to winter in Ecuador. He's from St. Louis and claims he's had his share of cold.

Is your roof ice dam proof? Remember, if the ice has melted on the body of your roof and not the overhang, the leak protector will help but you are improperly ventilated. You are not eliminated the warm humid air from your attic and it is melting the ice except on the overhangs. If you think a warm attic is a buffer, you are nuts. Once the heat is past your insulation it is gone and helping no one but your energy provider.

The Prophesy: Flat Roofs Are Ripping Apart

ein bin berliner  Ein bin Egyptliner....Godspeed to those who want what we take for granted and all prayers that they don't get something worse.

The soothsayers, the oracles at Delphi, Carnac the Magnificent, Nostradamus, and all the greats cannot compete with me in my realm.

Do you hear that giant tearing sound? Much time has passed since it has been this cold in Dallas and Dallas flat roofs have something to say: rippppppp!

As roofs age they lose flexibility. Roofs made of small sections, like sloped comp or slate roofs, don't experience as great a thermal shock as those that are welded into one giant bathtub. As they naturally shrink the membranes pull themselves off the perimeter flashing, penetrations, and walls. Seams in the middle of the roof experience stresses as wind, ground movement, and temperature changes banter the membranes about. yet the normal extreme is hot. now it is cold. Deep Yankee cold. Zero is pretty cold by even northern standards even if it is not forty below.

The bricks are actually expanding if they are moisture laden, the ground is doing the Watusi, and the inside is hot and humid, in direct conflict with the dynamics going on on the outside. Slam a few doors and run the heck out of the heating system and keep the humidity high.

As I said:rrrriiiipppp.

Come thaw day, which might be Thor day, or Thursday as we descendants of the Vandal culture have corrupted it, the relaxation of roof frigidity will bring a massive influx of roof leaks.

I'm not kidding. Any old coal tar pitch roofs will have fifteen foot rips, EPDM roofs will separate here and there, PVC roofs will fracture, and TPO roofs will find their weaknesses. There will be no exceptions on all roofs over 15 years old of any large scale.

The sound my office will hear will hear the next big rain will be "ring, ring, ring..."

Didn't I recommend annual inspections? Did you listen?

Jon Alan Wright

Jon Wright Roofing, Siding, and Windows

1915 Peters Rd., Suite 310

Irving, TX 75061

972.251.1818 Office

214.718.3748 Cell

972.554.8090 Fax

jonwright@jonwrightroofing.com

http://jonwrightroofing.com/

Master Elite Roofer: (Scroll to the bottom)