Does thin roof insulation work in summer?

Articles and videos posted on social media wrongly conclude that reflective thin insulation under a roof does little, because it does not do much against convection and conduction.

Which rather skips over its actual strength: dealing with infrared radiation.

According to self-declared insulation experts, reflective thin insulation creates convection, and with it discomfort.

The claim goes like this: by sending radiation back, the product keeps a fairly low surface temperature, which widens the gap between the room and the underside of the insulation.

That gap, they say, increases convection, meaning air movement, which is unpleasant to live with.

And to compensate, you would end up turning the heating up.

These armchair experts are tangling up conduction, convection and infrared radiation.

Here is what actually happens. The heat produced inside the home by the heating system and the various other sources warms the ceiling and gives it inertia.