“the only time I notice a difference in drainage speed is when I forget to clean the thing...”
That lines up with what I see all the time. You keep up with cleaning, you’re fine—skip a few cycles and you’ll get slow drains or even a backup. Under-sink traps are definitely easier to deal with for quick cleanouts, but like you mentioned, they fill up fast if you’re doing a lot of frying or heavy cooking.
One thing folks don’t always think about: with underground traps, you’re not just getting more capacity, you’re also keeping odors and mess outside. That can make a big difference if you’ve got a sensitive nose or don’t want to deal with grease gunk under your sink. On the flip side, those outdoor ones are a pain if you ever need to dig them up for repairs or a major cleanout.
For most home kitchens, under-sink is enough—but yeah, ignore it too long and you’ll regret it. Seen too many folks try to flush bacon grease down thinking hot water will “wash it away.” Spoiler: it doesn’t.
Honestly, I’ve lost count of how many times I’ve pulled a glob of solidified grease out of an under-sink trap and thought, “Well, there’s your problem.” Folks always think hot water is magic—until it isn’t. Underground traps are great for keeping the stink outside, but man, when you have to dig one up? That’s a whole weekend gone. For most folks who aren’t running a diner out of their kitchen, under-sink works fine... as long as you remember to clean it before it turns into a science experiment.
I get what you’re saying about the weekend lost to digging up an underground trap—been there, regretted that. But honestly, I’d rather deal with a little dirt outside than have to mess with the nasty sludge that builds up under the sink. The smell alone is enough to make you rethink your life choices. Plus, if you forget to clean it for a while, it’s like opening a horror movie under your cabinet.
That said, I get why most people stick with the under-sink ones. It’s just easier for regular folks who don’t want to start excavating their backyard. Still, I wonder if people actually keep up with cleaning them as much as they should? Or do most just wait until the water starts backing up and then panic? I’ve seen some pretty gnarly stuff in houses where folks “swear” they never pour grease down the drain... but the evidence says otherwise.
The smell alone is enough to make you rethink your life choices.
Ain’t that the truth. I’ve had tenants call me in a panic because they “just noticed” the under-sink trap was overflowing—usually right before a holiday dinner. Honestly, I prefer the underground ones for rentals, even if it’s a pain to dig up now and then. Less chance of someone ignoring it until it’s a biohazard under the sink. Still, you’re right, most folks don’t clean them until it’s too late... and then everyone’s sorry.
I prefer the underground ones for rentals, even if it’s a pain to dig up now and then. Less chance of someone ignoring it until it’s a biohazard under the sink.
Honestly, I get where you’re coming from, but I’m not totally sold on underground traps for every situation. Yeah, they’re out of sight (and out of nose range), but when they do need cleaning, it’s a whole production—shovels, maybe a jackhammer if you’re unlucky, and usually a mess no one wants to deal with. Under-sink ones are gross, sure, but at least you can see when things are going sideways before it turns into a full-blown disaster.
If I had to pick for my own place? Probably under-sink, just because I like being able to check on it without digging up half the yard. For rentals though... yeah, tenants never touch them until there’s a swamp under the cabinet. Maybe there’s no perfect answer—just depends how much you trust people to actually do the maintenance.
