Fermenting in a dusty room...

Since i have been brewing i have been fermenting in my office, using a clothes tub and ice water. It's working great. But my office is small and i'm starting to out grow this room already. I'm starting to have a few batches going at once. I have an attic space. Half of it is my son's room and the other half is unfinished. We keep most of our soon to be ebay items and other junk there. Unless i finish it,(which i'm not) it's basically a normal dusty attic.
I'd like to keep a couple of brews fermenting in there. My question is should i cover them with something just to be safe? I do brew everything in my kitchen. I've seen pic's on this forum where fellow homebrewers brew in unfinished basements and other places with exposed insulation and stuff. just wondering what you think before i start...Thanks.

I moved my brewing out to my garage when I went to AG. I had similar concerns.

I swept the cobwebs off the ceiling but other than that, nothing special. I brew with the door wide open. I just make sure that I cover the brew pot with the sanitized lid, the moment I turn the flame off. All of my plumbing from the brewpot to the chiller to the carboy comes straight out of the Iodophor solution prior to connection. I make a double hood of santized tinfoil to cover the carboy opening. I pull the hose from the carboy leaving the foil in place. Repeat the above for oxygenating and dumping the yeast starter. Every time I touch the foil cover, I hit it with spray sanitizer first. I pull the closure and blowoff hose from the sanitizer and install as quickly as possible. The carboy sits in a tub of water in the back of the garage. Believe me it's dusty. I do throw a big towel over the tub. The environment is never perfect, but with a little care, you can minimize the exposure to all of the critters.