I live in charleston sc in an old 1858 3 story wooden house.
Exterior roof insulation under shingles.
You need roofing sheathing plywood or osb to nail the.
Additionally insulation serves as a way to enhance sound proofing on the uppermost envelop of your house.
Stabilizing the interior temperature and help to prevent material from collecting under the roofing material.
Insulating in and around your roof attic space also prevents long term damage from moisture build up or ice damming which results from the warm air trying to escape through the apex of the roof but instead heating up the snow.
There are many kinds of foam insulation.
Plan to replace asphalt shingle roof with standing seam metal.
In other cases it is sprayed into place where it later expands and fills the space under the roof.
Kara lives in bc and has foam insulation over her roof with shingles over the foam.
Foam is also a suitable material for use under roofing shingles.
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Yes providing a layer of insulation under a metal roof is imperative because metal is naturally a better heat conductor than wood.
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.
Roof to wall air seal note the connection of the new roof deck membrane overlapping the trimmed back original gable overhang and catching the white housewrap water control layer and air control layer behind the wall exterior insulation the blue layer of foam.
The first problem is that shingling nails that have to go through an inch of foam will not hold the shingles well against high winds.
She wants to put on new shingles and questions having them right over the foam you are right to question that application.
Metal roof insulation addresses two major goals.
Nail it around the edges with roofing nails.
Rigid insulation under a cool roof in zone 3.