Simplicity of the application of this concept.
Upside down roof insulation.
An inverted roof also referred to as a protected membrane or upside down roof is form of flat roof in which the waterproofing layer is beneath the thermal insulation rather than above it.
With the insulation upside down the kraft paper is not working as it is intended.
In a warm roof construction the principal thermal insulation layer is located above the structural decking.
Crawlspace insulation installed upside down fiberglass insulation installed backwards diy insulation paper vapor barrier should be facing your interio.
The so called upside down roof is simply a rearrangement of the normal elements of a roofing system to try and overcome some of the disadvantages of the conventional arrangement.
Efficiency which is proven in most of world countries.
This doesn t work though if you install the radiant.
Benefits of inverted roofs the great benefit of inverted roofs is that the insulation protects the membrane from extremes of weather such as frost uv exposure and the expansion and contraction that comes about from summer winter temperature cycles which can be as much as 80 c on some roofs.
You don t say what r value the insulation has but chances are it s adequate for a floor in your climate zone.
Advantages of the upside down roof concept.
Rigid extruded polystyrene insulation has minimal water absorption due to its closed cell structure.
In it the air vapour barrier and the roofing membrane are combined and located on the structural deck with the insulation placed outside the skin like the fur of animals or the clothing humans wear.
This makes it the only material suitable and approved for inverted roof applications.
Insulation boards are loose laid on top of the membrane and then weighted down with paving slabs or gravel ballast.
This type of roof has normally been used over small extensions to dwellings using timber joists and plywood.
Moisture from inside the house can now accumulate in the insulation which will drastically reduce the r value.
An inverted roof is quite simply where the waterproofing layer is installed over the structural deck rather than over the insulation.
When foil insulation is properly installed the underside of the roof decking remains at or near the ambient temperature even in full sun.
