I'm working in an unconditioned garage that backs onto my living room, and I need to cover the foundation block with at least 1/2 inch gypsum due to an open cavity for vent stacks behind the thermopan. My question is whether I can secure the drywall directly to the block using tapcon screws, or do I need to use furring strips first? If furring strips are necessary, what should I do with the 1 inch cavity between them—should I fill it with something or just leave it empty?
2 Answers
I recommend using 5/8” drywall with a vapor barrier, then furring strips, and adding foam board between the strips. This setup creates an airtight seal between your garage and living space, which will help reduce exhaust fumes leaking into your home. It's a bit of extra work, but totally worth it for the insulation and overall safety!
You definitely want to go with furring strips! They create a barrier that prevents moisture from transferring from the block to the drywall, which is super important because moisture can lead to mold and mildew. If you're building to code (which you should), furring strips might even be required. Trust me, it's better to build it right the first time than to deal with regrets later! Also, generally, you leave that cavity between the strips open unless you plan to insulate the inside of the block.