I had an ongoing problem all winter and as most of you know this winter may well have been one of the coldest on record for the little town we moved into. I will try and explain whats going on and even though Im pretty sure I know the proper fix I dont know if I want to put that kind of work into this repair and wondering if there is any work around to it. The house we bought less than a year ago had a few changes made by the previous owner and most of them were not too good and had to be redone. The houses main entrance is thru the kitchen and the house way back had an entry closed in unheated mini porch / mud room and then a coming into the house a storm door and entry door. Many homes have these around here to break the weather and a place to leave muddy boots etc. His wife was ill and a wheelchair ramp was added and at that time he removed the entry door and storm door and sealed up this porch and put a new exterior door into the porch with a new storm door. Steel door and painted aluminum storm. And changed the cold room into a heated area to the extent the heat from the kitchen goes out there. The porch didnt have a continuous foundation it sat on piers made from blocks and I assume footings below. It looked like this had been working for them for a number of years but was still unfinished and an eyesore coming into the house. The skirting closing it in to the ground was made from vinyl and done by whoever sided the house and looked ok. I got in under the porch and saw he had insulated the floor with about 8 inches of foam. I figured I was ok with this structurally even though I wouldnt have built it like this. I finished the wiring and added a small replacement window in the one wall finished the walls and added to the floor to make it level with the kitchen and then when I did the kitchen floor I ran it out into the mud room. It looked very finished and makes an attractive entry to the house. As the weather grew colder I found the little room stayed nice and warm even the floor without heat below was ok. The problems happened when we started getting the deep freeze and the deep frost. I first noticed the new weather stripping sticking and I ended up taking some of it off. Then I noticed the dead bolt not wanting to find the socket. Then the door bolt was missing the striker plate and again the door was rubbing hard on the adjustable threshold. I adjusted that and the striker plate and was fine again for a few weeks. Then the door rub came back and the plate was missing again once again I fixed it this time with taking a die grinder to the striker plate. I found 3 cracks in the drywall that were allowing the movement. With asking around I found out this winter the frost was at a depth of 4 foot something that hasnt happened around here in maybe 100 years and it has caused a lot of similar problems for neighbors. The porch is set into a corner of the house and the three corners that are against the main house stayed good but the one away from the house the frost pushed up maybe a quarter of an inch. Im pretty sure the best fix is to brace things up and dig it all out deeper pour a good footing and build a good wall to hold this porch thing. Or better yet rip the whole thing off. (What I should have done before finishing it.) the third choice would be to support that one corner and take that one pier out and go deeper and build it back up. I really dont feel like doing any of those things and I had plans of replacing that door anyway come spring as its kind of a cheap door and I could repurpose it in the garage. So if I can live with this little movement if it ever freezes this deep again. Is there any way to mount a door so that it can float in the rough opening and still seal out the weather?