Proper installation of register boot

hartkem

I am about to start installing registers in the ceiling of my house. The house has plaster not drywall. I am wondering what the proper way is to install the flanged boots. Do I simply sandwhich the plaster between the register and boot to hold everything in place or is it a requirement that they are fastened to a ceiling joist.

kennzz05

not a requirement but it sure makes it easier bend 1/2 flange all the way round so theres something for the reg. to screw into

bluefitness

Yes, you can just screw the register to the boot and it will hold it in place. During new construction you would use boot rails to hold the boots in place.

You will need a friend to hold the boot in place while you screw the register in. If that is not an option, you can screw drywall screws into the boot to hold it in place. Just make sure that the register covers them up.

hartkem

So I don't have to attach the boot to a joist? The plaster is enough?

bluefitness

Yes..

hartkem

Ok that makes things easier. Is there a preferred location for the supply ducts. I will have one return in the center hallway in the house. I was going to simply install the ducts on the outside walls.