- Posted by: Ana
- Category: Advice, Attic Ventilation, Insulation
Does your home need more attic insulation? The best way to answer this question is to get a tape measure and go to your attic. If you don’t have 17 inches of insulation in your attic then you need to add insulation to your attic. Twenty inches will provide a good layer of insulation to keep your home cool in the summer and warm in the winter.
Insulation is measured in R-value. R-value is a measure of resistance to heat flow through a given thickness of material. In theory, the higher the R-value, the greater that resistance.
Unfortunately, R-Value has taken hold in the consumer’s mind as a universal method for comparing insulations. The higher the R-Value, the better the insulation, end of story. This is a little simplistic since other factors also determine your insulation’s effectiveness. If your insulation R-value is high but leaving gaps for air then the high R-value isn’t making a difference. This is why Excel Roofing recommends 17 inches of loose fill fiberglass insulation.
Different types of insulation include blanket roll, loose fill, fiberglass and cellulose. Cellulose has a tendency to settle and compact which loses the air pockets which are valuable in keeping your home insulated. Fiberglass maintains its form for a longer period of time. Blanket roll, or batts, doesn’t fill the space well. They leave gaps between the rolls and edges of your attic frame and joists. Blown in fiberglass insulation provides the best insulation for your home.
Proper attic ventilation is just as important as a fully insulated attic. The insulation will help keep your home warmer in the winter and cooler in the summer, but the attic ventilation will reduce moisture in your attic and help prevent ice dams.
In the summer your attic gets hot. If the air cannot move out of the attic then the air temperature continues to rise. This creates a strain on your cooling system. The heat in your attic can actually damage the asphalt shingles on your roof, causing them to blister in the intense heat. An efficient ventilation system can decrease attic temperatures by as much as 40%; cooling costs are reduced and living conditions in the home improve.
In the winter the heat from your home will rise into the attic. If it cannot escape, it will stay trapped at the roof where it will melt and cause ice dams at the eaves. The water vapor will also cause moisture to build up in your attic. If the moisture cannot escape you will get frost build-up and water damage in the attic of your home. Insulation will keep the warm air in your home and the ventilation will keep moisture out.