How Much Snow Is To Much On My Roof

The roof deck collects the snow load and transfers the weight to the rafters.

How much snow is to much on my roof. Two feet or more of old. So you most likely will never have to worry about removing snow from your roof. Packed snow however weighs more. As everyone knows cold fluffy snow is very light while wet snow can be extremely heavy.

We have some good news for you. Ten inches of fresh snow equates to about five pounds per square foot which means your roof likely can support four feet of fresh snow. Most roofs are built to support heavy loads of snow without having any problems all winter long. Most roof designs can handle snow loads of 20 40 lbs per square foot.

Our snow load calculator helps you to make the decision when to remove the snow from your roof by comparing the weight of snow with the load carrying capacity of the roof. According to the national research council of canada a roof should be able to withstand pressure of at least 21 pounds per square foot psf this number can fluctuate based on regional building regulations but any well built roof should be able to sustain this much weight before it gets too stressed. Asking yourself how much snow can my roof hold here is a list of indicators that may mean you need to move to a safer place. These questions aren t quite so easy to answer because there are several variables.

This has the benefit of providing the owner with more usable space at less than the cost of reinforcing the existing roof to carry the drifted snow. But as the chart below shows packed snow with ice can easily overload a roof once it reaches about 12 off depth. The easiest is to add a low section of roof the width of the drift adjacent to the existing building and design this low roof to carry the weight of the drifted snow see figure 2. For any rafter the portion of the roof deck that transfers this load is the tributary area.

The chart below courtesy of paul schimnowski p e gives some examples of snow loads. How much snow is too much for my roof to support. How much snow can my roof hold. How to protect your roof watch for ice build up on the edge and valleys of your roof.

So how much snow does this equal.