We recently built an addition over the existing screened porch in a 1970 yr Colonial home. The porch was made of 4ft high bricks and the 2 by 4's and it already had a tiled roof. The foundation is concrete and no water had ever been present since we lived here for 4 yrs. We wanted to convert the porch into a living room which was then attached to the kitchen.
The builder had to raise the floor 1.5ft by using floor joists to level up to the kitchen floor & left some of the old outdoor carpet which had been glued on the concrete floor underneath. He insulated under the new sub floor but I'm sure some of the insulation had dropped onto the concrete floor as there was hardly any space left between the insulation and the concrete floor.
He then built another wall behind the original 4 ft high brick wall to about 10 ft high.
The dimensions of this crawl space is 1.5ft (height) * 14.8 ft (width)* 18.5 ft (length).
He left 3 little gaps in between the bricks about the size of half a brick where my pest control guy has told me a snake/mice could easily live in there. 3 sides of the new addition has these holes and the other side is attached to a new patio.
My question is a) Do I need to take the current sub floor/joists out and have the builder put a vapor barrier down on the concrete floor & b) Is it necessary to put vents on the 3 exterior walls or do I seal everything up?
I have seen many insects recently in this new addition and I am worried about moisture and radon gas. Also I'm worried if I put new hardwood floors over this space, will I be expecting new problems in the future?