I have roaches coming up through the drain in my son's bathroom. Nowhere else in the house is this occurring. I am going to pour some product I found at home depot down the drain to help kill them. But am unsure if they are living in the drain or coming somehow from outside given that this is the only plumbing that this is happening in and the plumbing is connected to the HVAC overflow pvc which may lead outside instead of to the sewer connections. My question is this: Is there a tub drain that has steel wire mesh instead of the rather large holes? If not, can I permanently install a wire mesh basket in the drain? I don't want it becoming dislodged or my son to pick it up and move it. Any other options would be greatly appreciated.

Walmart and Home Depot have many, and some fit very snugly and come without a lip. You just have to know your drain size.

https://www.askmehelpdesk.com/image/...ooAKKKKAP/2Q==

Tub drain should have p-trap installed. P-trap holds water, therefore creates air-tight barrier that prevents odor and bugs from crawling inside tub. You may have either missing trap or cracked trap, which won't hold water and therefore allowing bugs to crawl in. Check if you have trap installed

Also, how often is that tub used ? If not too often then tub trap may dry out between uses, allowing bugs to crawl in

Where is the point of connection for the HVAC condensation line ? Cannot picture how they connected this PVC pipe into tub drain. That pipe has to be connected to the drain before the trap

They sell wire mesh baskets for catching body hair, but they significantly slow down drainage

Hope that helps

Milo

Sounds like you don't have a trap and or dumping into your yard. Is this your house or a rental? Where you live may allow gray water discharged to the outside but it still needs a trap for the very reason you asked about.

Roaches can fool you. Is it possible that they are living underneath the tub and are showing up in it after coming out through a crack? If you have seen them coming out of the drain then a p trap issue is almost definite, but check the caulking around the tub just to be on the safe side.