Or you can finish off the underside with vinyl soffit siding.
Screened porch floor insulation.
The job of insulating the floor is easier if there is room to crawl underneath but if there isn t it can still be done.
If you go with bat insulation i suggest you put some nails in the underside of the joists and lace the insulation in place with wire.
If your floor joist are 16 inches on center you can easily install bat insulation that is assuming you can get to the underside.
Roll out the fiberglass insulation sheets between the joists facing side up making sure it is snugly in place.
Start with the basics thermally efficient glazed doors and windows are essential to keeping the cold out.
Enclosed but uninsulated sitting areas are known as three season porches but if you live in a northern state cold weather can reduce that to two or even one and a half seasons.
Adding insulation batting to the walls and floor of your three season porch can extend its usefulness during cold weather.
Use a vapor barrier to keep your floor above free from condensation caused by the new insulated area.
Basically you should be thinking about insulating the roof floor and walls to ensure the maximum benefit.
Do it yourself video on how to insulate the exposed floor over an unheated area using roxul comfortbatt r28 canada or r30 usa and roxul comfortboard is i.
Make sure that you wear gloves and a mask for protection.
Insulating the floor is an important step in porch conversion.