How can I fix this problem? My condominium does not have a basement. The problem bedroom is located on the first floor and one of its walls backs to the sprinkler room and a car garage of the adjacent condo. I find that between the carpeted floor and the wall, there is an open space and cold air filtrates in making the whole room very cold in winter and cold the year round. The room also has a bay window and cold air also filtrates through the gaps but I find that the main problem is because of the open space on the floor. A solution is very welcome!
It sounds as if you have a concrete floor and may have a gap between the stud plate and the concrete. This is common with slabs but can be repaired by removing the baseboard at the wall and caulking between the gypsum board and the concrete or between the base plate and the concrete. If you have carpet you may have to pull it back to do a propper job. I suggest using a polyurethane sealant such as Sonneborn's NP1 but just about any better grade caulk will work. Don't use foam.