This is for a rental unit, so I’m trying to keep the cost low, while also sealing it away from silverfish. I have very fine steel wool on hand as well as a tube of DAP ultra clear flexible all purpose sealant.
You are a landlord, treat it like the business expense it is and hire a contractor.
What’s on the other side of the wall?
Regardless, I wouldn’t use the sealant you have. That’s a huge hole. Expandable foam could do it, but it might need to be fire rated if that’s a shared or exterior wall (check local code requirements), and that might be a bigger hole than foam recommends. Also, if there’s nothing behind the wall, the foam might just fall back into the void. Expandable foam also looks like shit, so if the spot is visible, do something that looks more finished.
The right way to do this would be to make the opening in the cabinet large enough to properly repair the wall. Cut a rectangular patch that fits around the pipes and secure it to studs, then spackle. If you make the gap smaller, then you could use the flexible sealant, but I still wouldn’t use clear.
Assuming you can’t just deal with the pest problem because you don’t control what’s on the other side of the wall, I’d put in steel wool to keep rodents out, and spray foam this side of it to seal off the insects.
Home Depot sells a high-expanding foam that’s supposedly pest proof. The Great Stuff Pest Block is probably what you want.
I used the pest block one (green can) to seal a few gaps in my house and it worked great! Keeps bugs and weather out!
Removed by mod
I would probably plan on fixing the hole by first cutting some pieces of (looks like particle board??) down to size and reducing the overall size of the gap.
Filling that thing with foam seems like a mistake in the making should you ever need to service it again and a kind of shitry diy cus I didn’t know better solution.
The hole in the back is more concerning to me. If that goes to the exterior of the structure you need to much more seriously consider sealing.
like wise those seem like water pipes? maybe gas? so condensation should be a consideration. You should put some kind of sealing insulation around them to prevent condensation build up otherwise you’ll be setting up a mold bonanza.
Honestly, with the tools and solutions you are proposing, just get a contractor if you are the owner. you prob gonna end up setting this shit up to be redone regardless, and thats maybe a 200 dollar job
