Garage Attic Insulation

[Trevor]

Hi

I'm about to insulate my garage attic space. It is a garage-cum-carport under one tiled roof. Last year I put down an attic floor that covers around 60% of the attic space, and my intention is to now add fibreglass insulation and then a wooden ceiling, effectively trapping the fibreglass insulation between it. In the open areas of the attic, once I put up the full ceiling, I will use blown insulation, but I will have to use batts in the other areas.

I erected drywall in the spring so the walls are already finished, but the attic and ceiling is something I have been putting off....

My question is - do I need to use a layer of plastic on which to place the insulation? Or can I just lay it on the 'ceiling' that I'm going to put up?


I live in a very variable climate zone - gets very cold here in winter.

Thanks in advance!

[Wgoodrich]

As long as the attic space has vents in soffitt, gable end and / or roof no vapor barrier is required. If you don't have the attic vented you need to consider doing so to allow moisture to escape the attic.

Just to be on the cautious side did you size your ceiling joists for attic storage or if the attic is to be used for human use as a floor joist sized to carry the load you are stacking up there?

Good Luck

Wg