But spray foam insulation used at the underside of the roof deck would need to be covered by a thermal barrier and intumescent coatings are commonly used.
No insulation in roof.
Run a 2x4 flat around the parmiter of the roof.
Fill the area with 1 5 inches thick polyiso.
Insulating and venting when there is no roof soffit may 21 2016 in most residential homes the soffit and associated vents is the structural part of the roof that hangs over the side of the home.
Reduce under roof insulation level to 3 fiberglass r 11 under the cathedral ceiling not good energy savings not recommended but functional just poor insulation value.
Strip off the roof.
Here are some older home cathedral ceiling roof insulation and ventilation options that you may consider.
There is no insulation in that ceiling and in the summer that room heats up and forces the a c to run constantly in what seems like a losing battle to cool that space.
Chauk line to idenify where your rafters are.
Here are just a few of the highlights.
Starting at one edge accross the roof to the other edge.
Proper insulation can significantly reduce your energy consumption heat in the winter ac in the summer and reduce your energy costs by hundreds of dollars a year.
The airflow from the soffits to the ridge vent keeps the roof cool and prevents ice dams and the material will block that flow.
The big concern with roof ventilation and insulation is moisture control in the roof sheathing.
Wood can wet without issue but keep it wet and then the problems arise.
This is bad for the environment and for your wallet as you end up spending a lot more on your electric bills.
For the same reason insulation shouldn t touch the roof s underside.
But with proper design and maintenance principles you don t have to sweat roof condensation issues.
The principle behind soffits is to allow air to circulate in and around the attic.
Covering up the soffit vents with loose fill or batts which can happen if you stuff insulation along the eaves is a huge no no.
The movement of air into indirect conditioning of an unvented attic is a slow gradual process that will not be noticeable by occupants and typically will not put any strain on the hvac system.
When you don t have any insulation you re constantly leaking lots of heat out the roof keeping the sheathing warm so if it gets wet it dries out quickly.
Adding insulation where it was never designed to go mainly the walls of an old house causes a host of problems all due to the moisture issues it creates.
Use construction adhesive between 1x4 and insulation board.
If your roof deck or insulation is developing water droplets chances are your forehead is too.