Cockroach smell behind wall

[Kapiira]

I'm trying to figure out how to get rid of the cockroach smell after getting rid of a cockroach nest in the wall of my house.  They are oriental cockroaches.

I called pest control and they treated inside the wall and along the outside wall.  Now I need to figure out how to get rid of the smell of the cockroach nest, which is what alerted me to their presence.  Right now, I have a hole drilled in the wall that is about 3" in diameter.  I duct taped a trash bag to the hole so that at least some of the cockroaches would die in the plastic bag instead of in the wall.  That was somewhat successful, though it's difficult to know how many more stayed in the wall.

Although a water leak in the area seems unlikely since there's no water or sewer pipes in that area, I'm buying humidity indicator strips to put inside the wall and make sure there's no source of moisture that would create mildew problems or attract future infestations.  I'm going to thoroughly inspect the outside of the house to eliminate pathways into the house.  I'm also going to do a really good job of sealing up the baseboards to reduce air leakage into the house.  Any other suggestions?  I recognize that I may need to cut out the wallboard and replace it, but I'd prefer to avoid that.

Disgusting cockroach smells in my bedroom, bags of dying cockroaches duct taped to my wall.  Ew gross.  I'm ready to be done with this.

[couponvan]

If not an exterior wall with insulation, could you attach a shop vac hose next to the cavity and vacuum them out? I'd be more apt to cut a 6-12" square to make sure I got them all and patch the drywall.  (I don't ever want to see a cockroach nest.)

[nereo]

You have a 3" hole in your wall already, so you will already be doing some drywall repair.  I'd cut out a section large enough to get a good look through and a dry-vac hose (maybe 8" x 8").  Such holes are easy enough to patch with a new piece of drywall and some mudd, sold at any home hardware store.

[Kapiira]

Good suggestion.  I will give that a try.

[HipGnosis]

Did you ask the exterminator how to get rid of the nest & corps' & smell?

[ChpBstrd]

Pour baking soda or paint down the hole?

[nereo]

pour paint down the hole?  What?? 

[Kapiira]

I did ask the exterminator how to get rid of the smell and they were pretty useless. I ended up cutting holes between three sets of studs and vacuuming out cockroach feces.  Lots and lots of cockroach feces.  While some is still stuck to the back of the wallboard, the room is smelling much better.

I put sticky board in the wall cavity and have some roaches stuck to it, so the exterminator is coming back to re-treat before the 30 day warranty is up.

I had put some baking soda in the wall cavity, but after I opened up the wall I realize that it was a fool's errand.  There was no way that smell was going to go away without cleaning it out.  My next step is to spray foam the bottom of the wall cavity which should reduce air infiltration from the wall space into the house, and also encase the remaining waste and keep the smell isolated.

[GuitarStv]

Make sure the exterminator uses a different chemical during second treatment.  Roaches develop resistance to pesticides very quickly.  The roaches you're capturing are all likely immune to what was used last time.

It's very important to clean up all the roach bodies.  Every dead roach will feed dozens of new baby roaches.  :P

[Rocketman]

Before you close up the holes get a product called Roach Proof or similar product. It is a white powder. It is roach poison. That way when you get one - it dies and doesn’t reproduce. Put it in the walls.

Good luck

[nereo]

Before you close up the holes get a product called Roach Proof or similar product. It is a white powder. It is roach poison. That way when you get one - it dies and doesn’t reproduce. Put it in the walls.

Good luck

For what it's worth, 'Roach Prufe" is 99% boric acid (the active ingredient) with some coloring added. You can buy boric acid cheaper on Amazon or through your local drug store or at a good gardening store, and it'll do the same thing.  Wear eye protection when applying (you don't want it getting in your eyes, but its otherwise pretty benign to humans).