What is the best way and healthiest to insulate our non-insulated walls in the bedrooms?”
your basic options are as follows: you can open holes in the top and loose fill with blow-in insulation you can open bigger holes in the top or bottom and push batt insulation up or down the cavity (I recommend encapsulated) you can hire a company to make smaller holes and pump in expanding foam you can remove the wallboard or plaster and insulate with batts, or rigid polystyrene insulation Pros & cons: you can’t just have scotty beam the insulation in, there will have to be holes blow in insulation is nasty stuff encapsulated batts are the least nasty fiberglass polystyrene has a smell to it that leads me to think it might release something early on that might make you unhappy with it at first, plus it has to be cut to fit. the final option involves residing your house and using an under-siding insulation.
