I've seen foil covered insulation sheets which really kills the signal from inside to outside.
You'll probably have to get another Wireless Access Point installed just outside and in line of sight for this to work well.
My current network is a Linksys E3000 router in the NE corner of my basement and a Coredy E300 as a access point in the SW corner on the second story. The Linksys is adequate for everything in the house, but it won't get any kind of signal to a camera on the S side of the house; I figured the Coredy would cover that. I was wrong.
I bought 2 Ring Spotlight cameras; and put one on the S side of the house and one on a tree in the front yard. The front yard one gets a poor signal from the Linksys, but the one on the S side doesn't get anything.
I complained to Ring and they sent me a Chime Pro extender. I put that on the opposite side of the wall from the S camera. It now gets a poor signal.
What is the problem?? It seems like signals just won't got though the exterior wall; which is just vinyl siding.
I bought a new modem (a Nighthawk AC2100) that had all kinds of great features, but it actually has a weaker signal than my 10 year old Linksys.
Any help would be appreciated.