Hot Roof Vs Cold Roof Insulation

The breakdown warm roof vs cold roof.

Hot roof vs cold roof insulation.

In hot roofs the insulation is typically installed close to the roof sheathing but the main characteristic is the space under the sheathing is closed to fresh air flow. Basically there are two options to choose from when insulating a flat roof. Namely the insulation layers. While some try to do this with fiberglass or cellulose their efforts are for naught and quite simply it is not allowed by any legitimate building code out there.

The bigger the r value the better it will insulate your home. Cold roof construction requires that a suitable ventilated air space exists above the insulation layer within which the air is constantly mobile being replenished by fresh incoming air whilst the air resident within the void space is being expelled via a natural vent action at another point. Basically the term cold roof refers to a traditional roof or vented roof while hot roof refers to a roof that is not ventilated and which has foam insulation attached directly to the roof sheathing. When we talk about a warm roof vs a cold roof what we re really talking about is the insulation of the flat roof.

Depending on the quality of the insulation hot air from outside can permeate the insulation and warm the conditioned space raising energy bills and making hvac units work overtime. A hot roof is one where there is no ventilation required as the insulation is directly attached to the roof sheathing. In cold roofs the outside air is allowed to freely flow under the roof sheathing. Warm roof insulation ensures the entire roof structure is insulated meaning a warm deck roof is more energy efficient than a cold roof.

Thus your unventilated roof is indeed a hot roof. Hot roofs or cold roofs. This can easily create attic temperatures as high as 125 f. In a cold roof the insulation is applied between the rafters but in a warm roof the insulation is applied on top of the existing roof surface.

Unvented roofs which provides a detailed explanation of each. A hot unvented roof requires that you pay meticulous attention to air sealing the attic. What s more cost effective. A hot roof contains the highest r value because there are no chances for air to leak.

Traditional roofs employing asphalt shingles vented attics and insulation on the floor of the attic can get extremely hot with surface roofing temperatures reaching up to 190 f during the summer. A cold flat roof insulation requires more work taking off old boards and replacing them and the roof surface. If the attic contains duct work it won t need to be insulated because there is no energy loss. You create a warm roof or a cold roof simply by applying the layers of the roof in a different order.

In this case you can learn a lot from foam tech s article vented vs. So what kind of difference does this make. A hot roof prevents energy loss and can lower your utility bills.