Not only that research by the u s.
Putting insulation in ceiling.
So i suggest you put your time and money into improvements that have a bigger payback such as adding more insulation in the attic weatherstripping your windows and doors sealing cracks insulating the rim.
Work from the perimeter of the attic toward the door or hatch so that you don t trample all over the insulation you just put in.
If you don t put the insulation around the back the pipe could freeze in the wall.
If you are seeking to add insulation to a suspended ceiling that is already in place however you will have to rest the batt insulation on top of.
If you have an attic there are quick ways to insulate the ceiling from above after drywalling it.
If you don t have an attic however there is.
This installation would proceed as any insulation installation.
How to put insulation in a ceiling before drywall.
Department of energy shows that there s not much to be gained by insulating a basement ceiling.
Always cover the tops of the ceiling joists to make sure the insulation is deep enough to reach your target r value and to prevent thermal bridging the heat loss that occurs through the wood framing.