Low slope roof insulation question

[Whalen68]

I have a 10 x 15 foot room that used to be a screened porch.  It was bricked in many years ago by a previous occupant.  The ceiling was in horrible shape.  I removed it.  Now I have 2 x 8 horizontal trusses and 2x4 supported roof deck.  

How should I insulate this before I close it back up?

 

[Bill Kibbel]

First, we need to know where/what climate zone.  If that's K&T wiring still in use, it should be replaced before adding insulation.

[hausdok]

Before you decide on what/how to insulate it. For good measure, saturate the rafters and underside of that wood decking with BoraCare so that it will forever after not support any growth of fungi. It's no more dangerous than table salt - just a pain to apply because you have to keep it constantly stirred to keep the borate in suspension.

Now, as Bill said, we need to know where/what climate zone.

[fenceanddeckconnection]

For your 10x15 room with 2x8 trusses and 2x4 roof deck, use rigid foam board insulation between the trusses for excellent thermal performance. Add spray foam or fiberglass batts to fill gaps and improve air sealing. A vapor barrier is important to prevent moisture buildup before installing the ceiling. This method ensures energy efficiency and long-lasting comfort. Good luck with your renovation! 

- Fence and Deck Connection

Edited October 29 by fenceanddeckconnection