There are at least two good reasons why this approach makes more sense than installing the insulation under the roof sheathing.
Rigid foam roof insulation.
The bottom layer of a single ply membrane roofing system is the roof deck or substrate.
Install it anywhere from the roof to the foundation.
Not only does it provide high r values but foam board insulation is also easy to install lightweight and can be used in any room of your home.
Rigid insulation is one of the best tools to reduce your energy costs.
Rigid foam insulation installation prepare roof deck.
The first step with roof installation is to prepare the roof deck by getting rid of all dirt dust and contaminants.
The ratio of insulation above the roof deck or air permeable insulation below the roof deck is a matter of climate and interior conditions.
In other words rigid foam can be applied on walls foundations and roofs and works great for both retrofits and new constructions.
There are lots of different ways to insulate this type of roof but one of the best methods calls for the installation of rigid foam insulation above the roof sheathing.
Polyiso is an easy cost effective sustainable and energy efficient construction material.
Rigid foam insulation also known as insulating boards provide high r values.
Foamular xps roof insulation for commercial buildings page 5 foamular xps roof insulation for commercial buildings foamular xps insulation is a rigid foam insulation which meets the needs of today s design professionals for a truly sustainable insulation product.
You can even place it under the foundation slab.
There s a reason polyiso rigid foam insulation is used in more than 70 of commercial roof construction as well as in many residential builds.
Rigid foam insulation packs a lot of r value into a thin package but not all rigid foam performs the same.
Insulation above the roof deck or air vapor impermeable insulation below the roof deck is needed for condensation control in an unvented roof.
Start at the bottom of the roof and place the first piece of rigid foam insulation against the metal flashing starting at the center line.
Choose rigid insulation wisely and consider the effect its characteristics will have on the performance of the your project overall product cost and the best way to get the bang for your buck.
Nail it around the edges with roofing nails.
The roof deck can be plywood metal concrete or wood planks.