The reason is simple when the inside roof deck surface emissivity is lowered from 95 bare wood to a lower value the result is a hotter substrate hence the logic behind the radiant barrier.
Radiant barrier on top of roof decking.
Some products are fiber reinforced to increase durability and ease of handling.
You are getting a new roof so why not scrape off the shingles put down roofing felt thenradiant barrier foil and thenshingles right on top.
Installed in over 1 5 million homes in the united states lp techshield panels also lower attic temperatures up to 30 f.
Radiant barrier under shingles scams bad information foil under shingles will not create a radiant barrier unless there is an airspace on one side of the foil.
The osb techshield radiant barrier osb is engineered to improve energy efficiency.
Also any water leak will fall onto the backside of the radiant barrier and roll down the slope until it reaches the eaves soffits.
The radiant barrier is installed on the top of the counter battens in non watertight applications.
This basically allows for wood rot to continue and inspectors have a more difficult time finding areas of concern.
Increasing summer energy consumption and cooling costs.
But on the bright side.
Radiant barriers consist of a highly reflective material usually aluminum foil which is applied to one or both sides of a number of substrate materials such as kraft paper plastic films cardboard oriented strand board and air infiltration barrier material.
As the original 1 brand of radiant barrier sheathing lp techshield panels vaporvents technology prevents moisture buildup during and after construction while blocking up to 97 of radiant heat in roof panels.
This reflection insulation also has high mechanical properties making it perfect for load bearing applications in construction.
Placing a radiant barrier directly under the roof decking as illustrated above raises the attic temperature and energy consumption between 2pm and 8pm.
At first it sounds reasonable.
The temperature of the attic space increases and that heat is transferred to the building below.
Attics heat up when the sun s radiant energy heats the shingles and the heat is transferred to the interior attic space through the roofing materials via conduction.
If the roofing material is watertight installing the radiant barrier on top of the felt with the batten on top of it would be sufficient.
Radiant barriers are utilized to reduce summer heat gain in attics.
In these attic space applications there is an air space below the radiant barrier.
A radiant barrier can be effective with an asphalt shingle roof only when installed inside the attic either to the underside of the roof decking or to the underside of the roof rafters.
Your radiant barrier makes the roof deck sheathing invisible from the attic.