My daughter is buying her first house, it came with a new metal construction Florida room. Basically in the summer it's too hot and the ac runs constantly. She wants to just put up regular walls with insulation, and plaster board on the inside against the preexisting metal walls, to cut down on the heat load. Is this possible or is there some reason it is not advisable? Several contractors she contacted said it's impossible, mold will build up between the metal and wood framed walls. They want to totally rip it down and start from scratch. The Florida room is only a few years old, she thinks that is wasteful, and can't afford what the contractors are asking. These metal walls are filled with about one inch of Styrofoam insulation.

 

Think insulation on the outside. What to clad it with? EIFS

 

The outside walls are clad with sheet metal, like the inside with insulation sandwiched in between. Another reason she wants to put up walls so it would like part of the house. Right now it looks like someone bolted a over sized garden shed to the house.

 

I don't understand the physics behind it but it is not a good idea to have two layers of insulation separated from each other but I think there are some exceptions. Talk to some insulation engineers and find out what will work then go with it. Seem like you might be able to build stud walls inside the existing and leave a ventilated space between the interior sheet metal and the back of the new insulation. Kind of like an envelope house.

Somebody knows a way to do what you want. You have to find them.