I get a lot of questions about watering house plants when I lecture and I have heard some heart breaking stories of wonderful pieces of furniture–& even a grand piano top–ruined by water from house plants. Yikes!
At my last lecture, someone told me that she has banned plants from the house just to avoid this sort of incident. That’s one approach, of course, but I do like to think that plants bring far more to the home than the watering accidents they cause.
So, what to do? Well, to the extent possible, try to keep plants on glass. You will save a lot of heartbreak and expensive refinishing that way. I have even had glass pieces made to cover some wood furniture so that I can use them as plant tables. It’s not perfect, but it helps a lot.
You see the saucer, above, that, I prefer. It’s heavy plastic, with little “feet.” Why is that better? First, the heavy plastic is less likely crack or leak.
Next, if you do water as you are supposed to, so that water comes out the bottom of the pot, there are those indentations (the feet) that catch the water and drain it away so the plant’s roots aren’t sitting in water. That’s nice.
And because it’s less likely to crack like the older version, shown below, no water is going to spill out onto your table, windowsill or where ever.
I do still have some of these flimsy plastic ones. I use them under ceramic cache pots on rare occasion, but only on glass tables.
I use them on my sun porch on wire plant shelves. But I wouldn’t dream of using them on anything wood.
With any luck, some of these ideas will help those of you who are worried about water damage in the house. Because truly, house plants, with their air cleaning abilities, do give back so much more than they might damage.
Gardendaze 
My furniture is all okay, but I ruined the carpet in my former home. Each carpeted room had at least one big rotten spot by the time I put new carpet in for the next tenant. I hated that filthy carpet.
You’re either much better with plants than most people–because they get big enough to become large floor plants–or you’re starting out with plants that size. Either way, most folks I talk to are never that brave. They start with 2 or 4 inch pots and when those die, that’s it–their commitment is over. So good for you–& maybe you should just back off on the watering a little bit to save the carpet.
Karla
I totally agree about those flimsy saucers; I did buy some recently but only because they were “temporaries” to put under the peony seedling growbags for their winter stint inside the garage. They will be planted out at some point this year (though I’ve no idea where, yet!) so can be tossed in the trash guilt-free. Two houses ago I had a bay window that was perfect for orchids and I found a translucent plastic boot tray that fit into about 95% of the rectangular ‘floor’ ($7.99 currently at The Containe Store.) Much nicer looking than the usual black ones too.
What a great idea about boot trays in bay windows. I will have to look into that. I have a couple of bay windows where I could definitely make use of that solution.
And those flimsy plant trays do have their uses. They are better than my footed ones outside on my porch. But inside? No, I don’t think so. Your garage sounds like the perfect place for them.
Karla