Like anything related to maintaining your home eventually your insulation "wears out". In most people's cases here in the Sarasota area, however, their homes were not insulated to the standards we go by today.
Government standards for insulation in the state of Florida recommend a level of R-38 which is about 14" of insulation. Code actually requires less than that which means even new homes are often built with less insulation than the Department of Energy recommends in our climate.
Chances are, you really need to at least add insulation to your existing insulation now but we will give you some things to consider as well that will help you determine if you need new insulation or not.
Air Conditioner Can't Keep Up
This is probably the most tell-tale sign that you need to re-insulate your home. If your heating and air conditioning system runs non-stop that means your home is not doing a good job keeping the cool air in and more importantly, the hot and humid outside air out. With a proper level of insulation, your air conditioning system should get a break in between cycles and your home should maintain a certain level of comfort.
You Get Allergies Indoors During The Summer
With proper insulation, you should not be getting drafts and allowing outside air into your home. Outside air carries pollen and other common allergens that cause people to get sick this time of year. Typically A/C filters help to filter these contaminants out but when there is too much of a draft, the A/C filters can't keep up and you get sick.
Your Home Is Old
Back in the 80's it was common in many areas to not have codes that required certain levels of insulation in your home. Chances are here in Sarasota if you have an older home, you may not even have insulation in your attic. If you do have insulation it may also be broken down and need to be removed and fresh insulation blown in.
It's Time to Insulate Your Home
Chances are if you are asking when is it time to re-insulate your home, it's time...
As you can see above the benefits of having a properly insulated home far outweigh the expense of doing so. As a matter of fact, insulating your home is the one thing you can do that actually pays you back every month in saved energy expenses essentially making the service free after a year or two depending on your current home energy expenses!