Insulating A Flat Roof From Outside

Cold roof systems are highly inadvisable as insulation from the inside will inevitably lead to the formation of condensation.

Insulating a flat roof from outside.

Unfortunately too many dwellings suffer from this problem. I explain problems with insulating a roof using the warm and cold roof construction methods. Insulated roof assemblies can be vented or unvented. When you have an un insulated roof you have to live with.

This is then covered with a further weatherproofing layer. A roof over a vented unconditioned attic does not need to include any insulation. Like other roofs insulating a flat one requires ample ventilation a vapor barrier and sealed bypasses. The material that works best depends largely upon preference in a given situation.

While insulation for a flat roof is expensive and can account for as much as 25 of the total installation cost there are a number of important benefits to having it in place. You would only do this however if replacing the roof covering on top and you have the height above the roof to do this. Why its important to insulate your flat roof. Not cheap but needs to be done right either way.

Cold roof a very bad idea. Or insulate partially on the exterior side of the roof sheathing with an air control layer insulate in the rafters bays control the vapor diffusion and re work the fascia soffit etc. The correct method for a flat roof is under the current regulations to have a warm roof. Fur down the rafters for more r value after evaluation air seal insulate and control the vapor diffusion.

Rigid foam panels are available in thickness. To produce a hot roof rigid insulation is fitted outside above the weatherproofing. The insulation material is placed between the supporting joists leaving a gap of 50 60mm between the roof and insulation. Reduce extreme temperature fluctuations inside your home.

Use rigid foam insulation panels on your flat roof before applying the final roof covering or inside the house before adding sheetrock or paneling. With this kind of roof the insulation follows the slope of the roof. In a nutshell you would sandwich 130mm of solid insulation between two decks allowing to place a vapour barrier on top of the first deck. However most cathedral ceilings and low slope flat roofs are insulated roof assemblies.

Whatever new flat roof covering you choose epdm rubber kemper. They lose loads of heat and are prone to leaking causing the materials to deteriorate.