Snow Insulation Roof

It does help with ice dams though.

Snow insulation roof.

Where you really see the amazing insulation properties of snow in action is in the igloo. Without the insulation properties of snow the inuit could never have survived in the harsh arctic wilderness. According to one anecdotal source a snowfall that measures about 0 07 inches in density or seven percent water volume has about the same insulation value as a standard batt of fiberglass insulation with an r value of 18. In extreme snow regions it is typical to add a vented air space between the roof cladding shingles and the rigid insulation in figure 7 to flush heat away trapped due to the insulating value of the snow the snow becomes an insulating blanket.

But on average snow has an r value of 1 per inch about the same as wood. If you re shoveling a tad too much you can damage the roofing tiles. Snow is an insulator. Many homeowners report that their homes feel warmer after a good snow as long as there s enough insulation in the attic floor to keep that heat inside and the snow on the roof.

In fact having a reasonable depth layer of snow on a roof is a good thing as long as the roof is designed to handle the weight. A properly insulated home doesn t show bare patches of melted snow on the roof. Twelve inches of snow have roughly the same insulating value as a 2x4 wall filled with fiberglass insulation. In essence creating a vented unvented hybrid roof assembly.

Snow accumulating in decent amounts on your roof without melting in certain unusual spots is a testimony that your attic is doing its job meaning there s no heat loss through the roof due to poor insulation. A house that has a bare roof when all the others in the area are covered in snow or has excessive ice formation is a sure sign of poor insulation and inadequate. Additionally insulation serves as a way to enhance sound proofing on the uppermost envelop of your house. Nailbase must be vented in high snow load areas.

That cold air vent space disallows help from the snow it would seem. A layer of snow insulates your house from above preventing the heat from escaping and thus significantly lowering your electricity bill. Install nailbase for cladding. You have insulation layer snow cold air space vent then the insulated roof deck.

Of course that amount of snow on a flat roof that s not built for it is going to cause all kinds of other headaches. Its r value varies depending on moisture content and density of the snow granules. And more importantly where should you store all of it. Rigid insulation layers exterior to existing roof sheathing must provide sufficient thermal insulation r value to control condensation risk see climate specific guidance.

It is a sign that the roof is adequately insulated and vented. It also provides an additional level of insulation and protects the roofing material from sun exposure which is your roof s worst enemy.