Floor insulation question (Mobile home issue)

Hello folks, I am a new owner if a doublewide home made in 98 and we have finished inside remodel and now I'm just now tackling the belly, I went to do some winterizing a couple days ago and discovered that I'm missing a 20x20 area of my belly wrap (floor insulation, also called belly board I think) and its also where all my plumbing is, I assume a water leak happened here and repair was done and the insulation was ruined and never put back...We are not sure on how long we plan on keeping this mobile here or build on land that came with it...most likely i'll keep and modify as money allows.

So I'm left with a problem its going to drop in the teens here in a few days and need to deal with this asap!

Some info...My skirting is made up of 4''x 12'' cinder block and has vents that now have foam blocks in them and house is 1792sqft, I have a 2.5ton heatpump

Option #1
Do I repair missing belly wrap, it appears I could use tyvek and R19 insulation and accomplish this, but its very tight in there.

Option #2
Do I remove all of it, insulate my block skirting with a rigid foam insulation and seal, call it good ? this would add roughly 800sqft to my heating space and I think my furnace can keep up with it.


Option #3

Can I get away with l sealing up air leaks in skirting ( I know I have some) and leaving as is? not sure if pipes will stay thawed or not.

:help:

Wecome to the site You should do one or other. The insulation in the floor need to be kept dry and venting helps with that and the pipes should also be insulated. Closing it up with insuation on the block wall also requires waterproofing the ground with poly. So either way you are crawling around in a tight space.

I wouldn't want to add 800sqf of heating space - even if my pump could handle it. I'm not familiar with mobile homes, but can you use rigid foam boards on the underside? R12 for 2" board.