A vapor barrier in sidewall insulation is almost always a good idea.
Polystyrene is considered an excellent choice for garage door insulation due to it's high moisture insulating properties. It is otherwise known as "beadboard". http://diygaragedoorinsulation.com/garage-door-insulation-panels-know-your-materials/
You should put a plastic moisture barrier between the concrete and the studs so that moisture will not get to the insulation.
It keeps cold air out in the winter and warmth in. And keeps hot summer air out and cool air in. The insulation traps pockets of air which slows down the transfer of heat from one area to another. The material which makes up the insulation also slows down the transfer of heat. This slowing down is called resistance, hence the measurement on insulation, R-values. Some insulation do act as an air barrier (and some can even act as a moisture barrier); however this is not always the case. In modern building methods, we use an additional air and/or moisture barrier to help maintain the comfort in the home. You do not want to stop air flow in all situations, and you really do not want a moisture barrier in areas along the Gulf Coast- this can harm the structure of the home.
It keeps cold air out in the winter and warmth in. And keeps hot summer air out and cool air in. The insulation traps pockets of air which slows down the transfer of heat from one area to another. The material which makes up the insulation also slows down the transfer of heat. This slowing down is called resistance, hence the measurement on insulation, R-values. Some insulation do act as an air barrier (and some can even act as a moisture barrier); however this is not always the case. In modern building methods, we use an additional air and/or moisture barrier to help maintain the comfort in the home. You do not want to stop air flow in all situations, and you really do not want a moisture barrier in areas along the Gulf Coast- this can harm the structure of the home.
Skin provides a waterproof barrier that maintains the body's moisture. It also provides insulation that helps keep body heat in the body.
Doctor Energy Saver of Connecticut installs garage insulation in the Manchester area. Garage 911 is another company in this locale. Insulation Pros is another.
If you're installing insulation yourself, remember these guidelines when using a vapor barrier: * Always place the vapor barrier towards the warm side of the insulated area - facing downward on the attic floor or to the interior side of the wall. * When adding a second layer of insulation to an attic, do NOT add a second vapor barrier - this can trap moisture inside the first layer. Use loose-fill or unfaced batts or blankets; if only faced batts are available, cut facing every few inches to allow air to pass through. * If the vapor barrier tears during installation, tape it tightly. * If you have a crawlspace, add polyethylene vapor barrier on the floor of the area to reduce condensation from ground moisture.
A person can buy a garage door insulation kit through Ebay. Energy Efficient Solutions makes garage door insulation kits. The price of a garage door insulation kit is approximately $90.00. These kits are also made by a company known as Atlas EPS.
Radiant Barrier is essentially insulation that can be found anywhere where regular insulation is installed. Radiant barrier is foil and can often be seen covering duct work.
Because warm air can carry more moisture w/o causing condensation than cold air. If you had the moisture barrier at the cold side warm moist air would hit the cold surface and fall out as condensation, leaving water in the insulation.
You're probably thinking about Tyvek. It's used as a wind-proof but moisture permeable barrier and it's needed for the insulation to work as well as possible.