When installing board and batten siding, make sure there is wall sheathing and a moisture-resistant barrier installed. Behind that sheathing should be plywood or OSB for you to nail the boards and battens into. If there isn’t plywood or OSB, you can install vertical furring strips at 1½- to 2-foot intervals to nail the boards and battens to.

While insulation is required for all exterior walls in a house, it is not typically required for interior walls. Local and state building codes mandate that new construction homes have adequate insulation in exterior walls and ceilings to suit the local climate.

However, there are several benefits to adding insulation to interior walls. It is excellent for sound-dampening between rooms and can help with temperature control by maintaining a regulated temperature in specific rooms and lowering heat transfer between adjacent areas. Insulating interior walls can also contribute to the overall energy efficiency of your home.

The lifespan of crawl space insulation depends on how well you maintain your insulation and the type of insulation. Fiberglass will need replacing every 15 to 20 years on average if you don't have a vapor barrier in place. If you do have vapor barriers in place, then your insulation could last much longer. Spray foam insulation can last anywhere from 80 to 100 years. 

If you feel your energy bills are too high or your HVAC system is working harder than necessary to maintain the correct temperature in your home, you may have an under-insulated home. If you’re unsure, consider having your system’s efficiency assessed by a local independent energy auditor.