There are different types of insulation and different ways to install the insulation. Also, there are different places you should insulate.
If you use your attic for storage and have the floors covered in plywood, that is a problem. That is because the flooring limits the amount of insulation you can put in the attic. So you might need to take up the plywood and find someplace else for what you are storing.
Types of Insulation
The two most common types of insulation are loose fill and batts, also known as blanket type. Most people are familiar with these two types but few are aware of radiant barrier foil insulation. This foil type insulation uses different properties than traditional insulation to provide insulation.
Loose fill Insulation
In some cases this is spread around by hand, but typically it is blown in with a machine. There are certain situations where it makes more sense to use this type:
- When there are areas that are hard to get to because of obstructions, etc.
- When the joists are not the standard width
- When you are adding insulation on top of existing insulation because it will fill in any gaps
- When there is little headroom to work in
Loose fill can be of three types, fiberglass, cellulose or mineral wool. Fiberglass is lighter but you need more of it. Cellulose is common but if it gets damp, it can rot. The mineral wool costs a bit more but has natural fire resistance since it is made from rock or slag fibers.
You may remember seeing ads for this with the Pink Panther. The reason is that it comes in rolls 16″ or 24″ wide with pink fiberglass attached to paper and foil backing. In addition, it comes in different thicknesses which have different R values. An R value is a measure of insulation effectiveness.
It is best to use this in the opposite situation of the blown-in loose insulation. In other words, when the joist spacing is standard, there is easy access to the attic space, and there is enough headroom.
Radiant Barrier Solar Attic Foil
Heat is transmitted by conduction, convection or radiation. Infrared radiation heats up the roof of your house. Then through convection and conduction the air in your attic heats up which then transmits the heat down into your house.
Regular insulation works by having lots of little air pockets and reducing air movement so convection has less of an impact. But if it gets hot, it can still transmit heat by convection. So, what to do? You can take care of the problem by using a radiant foil barrier. It is basically a large sheet of aluminum foil with thousands of little holes in it so it won’t trap moisture. Aluminum reflects 97% of radiant heat. Only silver and gold foil reflect more at 98 and 99%.
By putting the foil insulation on top of the other insulation most of the radiant heat reflects back into the attic. The top of the regular insulation is 20-30 degrees cooler that it would be without the foil. That means less heat transfers into the house and you don’t have to run the air conditioning nearly as often.
You can think about the difference on a hot day when the sun is out. If you stand in the sun, you can feel the radiant heat. If you stand in the shade, even though the temperature is the same, you feel cooler because you are only being heated by convection from the air and not radiant heat from the sun as well.
If you are building a home or completely remodeling and have taken down the interior walls, you can staple batts of insulation in between the joists. Otherwise, you will have to blow in the insulation.
If you have an older house, you might want to check to see if you have any insulation in the walls. Energy used to be so cheap that people didn’t bother with insulation. If you have to add insulation, it is not a fun project.
You have to cut a circular hole near the ceiling and one near the floor. You need two holes because the pressure of blowing in the insulation could blow out the wallboard if you didn’t have a place for air to get out.
The bad part is that you have to cut the two holes every 16 inches in the walls around the outside of your house on all floors. The reason is that the studs, which are every 16 inches, keep the insulation from going sideways, just up and down in that narrow area. Then you have to take the circles of wallboard and plaster them back in place and then repaint all the walls. Not a cheap process, but usually worth it for the extra insulation and lower heating bills.
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