How do you insulate your wall in the attic or basement with reflective sheets? It's not all that of a complicated process. In fact, it's quite simple to do, just a bit time-consuming. One usually ends up applying a reflective coating over their already existing insulating system.
Now there are multiple ways of installing reflective insulating sheets but the most commonly used ones are the:-
When they make use of the staple tab product, which has slight tabs on each side of the material making it easy to staple in between the stud cavities. Or, the second is when the use of normal standard rolls are used. These usually are 48 inches wide in breadth and 125 feet long feet foil double bubble foil insulation.
Now since the staple tab products are small rectangular sheets it can be put on and simply stapled between the stud cavity but the standard roll, that needs to be installed perpendicular to the studs. The way one goes about it is as follows:-
You tag one end of the reflective sheet to one end of the wall and pull it all the way up to the other end. You hold it down, adjust it right before you attach it firmly to the wall. Now that you've gotten the sheet in place all you got to do is add a few staples along the wall and you're good to go. Follow the same process until you've completely covered the wall with the reflective sheets.
In case you don't wish to go through with the task you could look out for assistance for places that deal with glass wool wall insulation material.