Redoing underbelly - bad idea?

[nmdeskjockey]

Hello!

Long time lurker, first time poster.

I finally found a contractor to do a perimeter foundation for us. We've had severe mouse problems. They've made nests in all kinds of places using insulation from the underbelly. There's so many holes and even though I've patched them all, I can still feel the air conditioning blowing across my face. Also, this last winter, some of our heating vents started blowing cooler air. It's just in select rooms on both halves of the house where I've heard mice chewing on metal in the night. It may be my false assumption that the mice have managed to create gaps in seams in the ductwork?

I asked this contractor about gutting, checking the vents, and putting up new insulation and underbelly material. He keeps hedging saying it's a lot of work, which I'm quite aware of. He just wants to patch the holes and skip the ducts. Today, he brought up doing blown-in insulation. Seems reasonable, but I'm no expert. Would this cause a problem with heat around the water lines? Am I worried about the ducts for no reason? We are in the southwest, but we do get down to -30°F for days during the winter. I'm more than happy to spend the $ to make sure everything's going to be as energy efficient as possible.

Thanks ahead of time for any opinions.

[1987Commodore]

It sounds like you really need to have the duct work examined. I think it may have separated. It was probably poorly made to begin with, and would benefit from being sealed. The mice won't make holes in metal, but they will take advantage of any they find. Blown in insulation will be a real mess if you have to get in the belly again, for a water leak etc.

[Greg]

Exactly, No blown in for the belly. Sooner or later you WILL need to open the belly for repairs.

Greg

[nmdeskjockey]

Thanks Commodore & Greg, I didn't even think of that obvious downside! I was thinking about it settling in the bottom center of the fabric drapes over time. And with the duct work, I was thinking that yeah, they were just taking advantage of, and separating further, any gaps that existed. Though, yes, they have definitely been chewing on the metal, it's a very distinct and loud sound at 2am..... Evil little devils.

I just hate having to argue with the man. I'm tempted to just tell them to leave it and I'll mess with it next summer, but it will be that much harder to do with it blocked in. I wouldn't deal with him, but there's no way I can do it all on my own before winter and we just can't go through another year with the mice and water rushing under the place. Plus, he's the only one within 500 miles that does this stuff and that mostly knows what he's doing. He's going to be getting an earful from me in the morning since I came home to some pretty bone-headed moves. Shiny new frost free faucet - that I can't connect my A/C water line to while the line just dangles next to it. Brilliant.