Roof Snow Insulation

2018 international building code.

Roof snow insulation.

Twelve inches of snow have roughly the same insulating value as a 2x4 wall filled with fiberglass insulation. On the poorly sealed and insulated roofs the snow on the roof melts which in turn freezes at night creating the ice dams. And more importantly where should you store all of it. In essence creating a vented unvented hybrid roof assembly.

A layer of snow insulates your house from above preventing the heat from escaping and thus significantly lowering your electricity bill. Your roof is built to withstand snow but if the old accumulation hasn t yet melted away more snow on top of this older wet layer can be quite heavy. On the upcodes website. If you re shoveling a tad too much you can damage the roofing tiles.

They are hard to prevent with some of the huge snowfalls that occur but the houses that are better insulated and sealed in turn allow less heat to escape to the attic and therefore have less melting of snow. Generally most roofs max out at about 20 pounds of snow per square foot which translates to around two feet of wet snow or up to four feet of light fluffy snow. In some cases roof snow melt systems or heat tape can be used to combat ice accumulation on eaves and in valleys. Proper roof ventilation and high r value roof insulation is essential to minimizing ice dam formation.

Who would have the energy to spend each morning meticulously shoveling the snow off the roof. Also extremely relevant to roofs with sections on rain loads snow loads and wind loads. 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. Chapter 16 structural design.

Once you notice the differences you can begin to interpret what that means for your home s insulation. But on average snow has an r value of 1 per inch about the same as wood. Additionally insulation serves as a way to enhance sound proofing on the uppermost envelop of your house. If you roof has a nice even snow cover it means your home is well insulated and vented.

Its r value varies depending on moisture content and density of the snow granules. 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 properly insulated home doesn t show bare patches of melted snow on the roof. Insulating in and around your roof attic space also prevents long term damage from moisture build up or ice damming which results from the warm air trying to escape through the apex of the roof but instead heating up the snow.

Pat yourself on the back while enjoying the comfort of your home.