My house is a typical 2 storey house with the bedrooms on the top floor, living / dining / kitchen etc on the main floor and of course there is a basement. The exterior is stone up to about 7 feet from the ground and the rest is aluminium siding. The house is about 20 years old The floor on the 2nd floor has always been cold and when I was renovating the master bathroom I had to cut a section of the floor to modify the plumbing. There I noticed that a lot of cold air was coming from in between the floor joist and there was no insulation. My questions: 1. Does the space between the joists under the 2nd floor needs to be ventilated and if yes what is the reason? 2. Can I install Fiberglas insulation (which will obstruct the ventilation) in between the joists? Thank you

First off, thanks for this forum. I am very new to this so bear with me. My wife and I bought a 35 year old house that needs repairs and the first was the kitchen. Years of water damage and a mold metropolis have led to us demo'ing the base cabinets and removing the 8 layers of flooring all the way down to the joists, it was like archeology, anyway I am almost finished with the subfloor. After sistering a few of the joists I installed 3/4 osb with both glue and 2 1/2 screws at 2" edge and about 4" along each joist. The kitchen is 22' X 11.5' with the joists running the width. I staggered the seams and the floor feels very solid even if I stomp around intentionally. My question is do I need to put a layer of plywood down over the osb or is the 3/4 inch osb sufficient? We will be floating a vinyl plank floor. If it is not enough should I put down a vapour barrier then plywood screwed into the osb only avoiding the joists? Or should I screw into the joists as well? We are on a limited budget and I just figured out the water heater is out too :mad: Thanks