Ceiling installation question

[jtgt25]

I'm looking for input on removing the metal ceiling. (We already sealed and reflective siliconed the roof.)
We are putting cedar planking on it either way. But do we fully remove the metal ceiling first then install these 1/6 inch planks or keep metal up. like a cooler would be insulated metal or plastic both sides insulation in the middle. Or does not having the metal above the wood reduce conductive transfer via roof-frame-ceiling.
I removed some of the metal and noticed the insulation, which is synthetic bats, is clean and in great shape so no worries of mold.
Only other thing is about a quarter inch of clearance I'll lose but if keeping an extra layer helps moderate the temperature I'll keep it up(plus saving a day of labor or two.
Lastly I could keep metal , install 1/4 insulation over and then wood. Lose about 1/3 inch height

 

[EastCoastCB]

If insulating is the plan definitely ditch the metal "headliner". Makes for a really nice finished product.

 

[jtgt25]

Will that help as I plan to put cedar up over it and its already fully insulated under it?

 

[BlackJohn]

I pick this, " Lastly I could keep metal , install 1/4 insulation over and then wood. Lose about 1/3 inch height".


A slight addition I would add is a vapour barrier over the metal ceiling as the first layer, maybe even reflective material, whatever that is called, Refelctrix?
Using cedar will help absorb any condensation you create in your bus if not treated. Let it colour naturally. Voila, nice ceiling and not to intrusive height wise.


John

 

[brokedown-SKO]

You're losing 2 inches of potential insulation if you leave the metal ceiling up (or put it back up after uselessly putting insulation in the gap)

 

[jtgt25]

It already is filled tightly with insulation bats above the metal. Are you saying that that is bad?

 

[brokedown-SKO]

It's not doing much good, heat transfers through metal more effectively than through air. Probably doing more sound deadening than anything temperature related.

Consider your metal roof, metal frame, and metal ceiling as a single thing.

 

[jtgt25]

True I thought about that as well. I was hoping that with the wood over it that it would be enough to stop the small amount of transfer and act as a cooler. But perhaps not. I will say that using the tropico reflective silicone over the whole roof helped quite a bit. Having solar panels made a little difference and I'm hoping there is a large difference once I install a back deck above the rear.

 

[CaptSquid]

A wooden overhead will insulate better than the metal.