Cold Roof Build Up

Typically roofs with terrains of 10 to 20 are often referred to as low pitched roofs.

Cold roof build up. I also learned to build what s known as a cold roof. In this video i explain three different ways of building a flat roof using the war. The scenario for a leaky conventional roof in snow country goes like this. In a cold roof build up the vcl normally ends up on the underside of the joists or rafters and is punctured many times when covered over by the internal finishes.

The ice traps meltwater which can seep back up under shingles and drip through the roof into your house causing wet and stained ceilings and walls and peeling paint and rot. All the substrates must be flat dry and sufficiently resistant to stress e g. Cold roof on vented plywood. Cold roof insulation is most commonly used when a flat roof is first being created because it s a relatively easy process.

They help prevent wood rot and can prevent ice dam. A cold roof is roof in which the thermal insulation layer is located between the ceiling joists meaning that everything above the insulation such as the rafters and any roof space will be colder than the living space below it. Plywood boards must be at least 18mm thick and of exterior grade. Pull out force of 50 dan per standing seam fixing clip.

I m often asked what the difference is between a warm roof and cold roof. The snowmelt runs down the roof beneath the accumulated snow refreezes when it hits the cold air at the eaves and blocks the flow causing an ice buildup and often a leak. Ice dams happen for a number of rea sons but mostly they involve insufficient insulation or poor roof venting. When warm damp air permeates up through the ceiling and reaches the cold roof space the change in temperature can result in condensation forming.

This resistance needs to be guaranteed through ageing and humidity. Water running down the roof refreezes when it reaches the colder roof edge forming a mound of ice. The vcl in a cold roof construction. It requires the existing roof surface to be ripped up so that the insulation can be laid in between before a new roof surface is then placed over the top.

Such a roof paired with a boston ridge vent prevents ice damming and roof leaks. The wooden rafters conduct heat much more than insulation which means you end up with something called thermal bridging. Should the ceiling below also have downlighters the vcl could be seriously damaged and therefore virtually useless. However cold roof insulation on an existing flat roof system is anything but simple.