How much snow can a roof hold?

You should be ok with that much snow. A roof can hold a lot of weight. A quick check on whether you may be in danger would be to go up to the second story and open and close the interior doors. If any of them rub the door frame and didn't before you got all the snow, you need to clean your roof off ASAP. Snow can weigh up to 20lbs per cubic foot.

The building codes calls for a roof design between 25 and 50 pounds per square foot. Fresh snow can weight about 6 to 12 pounds per cubic foot. So 1.5 feet of snow would put a load on your roof of between 9 and 18 pounds per square foot. At 2 foot of snow the load will be between 12 and 24 pounds per square foot. If it gets to 2.5 feet then the weight will be approximately 15 to 30 pounds per square foot. That is the time when I would start to think about getting someone to get some of the snow off.

Hopes this helps.

The problem will develop when the first warm storm comes in and you get rain on the snow. The snow will hold a great amount of water before it melts. This may make a 10 pound load of snow per square foot suddenly be 200 pounds and then is when the roof will collapse. Either remove the snow your self or hire it done before the storm comes in.

Just a shot in the dark, but won't sun exposure melt the snow before it has a chance to build? I'm unsure of the load a roof can withstand but I am very certain weight was taken into consideration when building your home.

Are you sure they're not having it remove for other reasons? Such as heat containment or drainage issues?

Part of the calculation is based upon the angle of the roof - the pitch. This is factored in for the 100-year snow design load when they build houses to building code. If you are concerned, you could hire a structural engineer to assess your building.

More likely it's to prevent ice dams from building up. Ice can form under a thick blanket of snow and trap melt water. This can happen if you have insufficient insulation in your attic and a lot of heat escapes up through your house (which can melt the snow).

There is a reason why they are doing that. Better if you would have walked out and inquired. You probably could have worked out a good deal on the price. Talk to the person that had the work done. Better safe than sorry. People love giving advise especially when you ask for it. Nice way to bond with neighbors too!