Check the R-value of your insulation The R-value is a measure of an insulation's resistance to heat flow. The higher the R-value, the better the insulation. Different types of insulation have different R-values, so check the label to see what the R-value is for the insulation in your home.
You can assess if your home insulation needs replacement by observing signs like increased energy bills, uneven indoor temperatures, drafts, and visible damage to insulation materials. Additionally, if your insulation is over 10-15 years old or has been exposed to moisture or pests, it may require replacement.
Loft insulation usually lasts 40 years or more if properly maintained and pays for itself many times over its lifespan. However, this greatly depends on how well it was installed and the type of material used.
Removing old insulation is generally recommended if it's damaged, contaminated with mold, or infested with pests. However, if the insulation is in decent shape and just needs a boost, adding a new layer on top can be a cost-effective option.
Some loft insulation materials also reduce in terms of levels of thermal resistance as they settle over time. Home insulation experts advise householders to check the condition of their loft insulation every five to seven years.
Attic insulation costs anywhere from $1,680 to $3,125, depending on the size of your attic and the material used. On average, most homeowners shell out around $2,380. These costs include the insulation materials and installation by a professional.
The answer is yes, you can put new insulation over old. But there are some circumstances that would require insulation removal first, such as in the case of contaminated insulation from pests, water or smoke. Moisture is the biggest culprit, as it can lead to mold and mildew, as well as ceiling and roof rafter rot.
Look for drafts in your home
Another way to check is to look for drafts around windows and doors. If you can feel a draft, that means that warm air is escaping from your home, which means your insulation isn't doing its job properly.
Also, when laying down additional insulation, work from the perimeter toward the attic opening. Never lay insulation over recessed light fixtures or soffit vents. Keep all insulation at least 3 inches away from recessed "can" lights, unless they are rated IC (Insulated Ceiling).
Too much insulation will leave humidity and moisture to accumulate in your attic space. This can lead to mold growth on your walls and insulation. There might also be water damage to the support beams in your home's roof.
There are real dangers from old loft insulation within houses, which can contain asbestos, a carcinogenic material. For newer insulation, however, as long as precautions are taken during handling and installation, they will not be dangerous to the health of users.
Another sign your attic insulation is contributing to heating issues in your home is if you notice different temperature zones throughout the house. If your downstairs living room is a comfortably warm temperature while your upstairs master bedroom is freezing, there's a good chance your attic insulation is lacking.
Too much Insulation with a minimum amount of ventilation will result in condensation forming as the warm air has nowhere to escape to. It can also result from insulation being improperly installed such as too many layers being laid on top of each other or if it is too tightly packed.
The Big Question: Do I Need to Remove Old Insulation Before Installing New? In the majority of cases, removal of old insulation is NOT necessary before adding new.
One important thing to remember is that insulation should never be pushed right into the eaves because it will interfere with airflow. If you're going for a warm loft then you'll need much more insulation to be able to cover the underside of the roof along with the gable and party walls.
Conclusion. Attic insulation can last 80 to 100 years, though it loses its energy efficiency benefits with time. Certified attic specialists' professional advice is to upgrade it every 15 years to ensure that it is still performing the job.
SAVINGS AND COMFORT
EPA estimates that homeowners can save an average of 15% on heating and cooling costs (or an average of 11% on total energy costs) by air sealing their homes and adding insulation in attics, floors over crawl spaces and basements.
High Energy Bills
You may not notice extreme temperature shifts in your home if your heating or cooling units are working overtime, but you will notice your extreme energy bill. If wasted heat is escaping through your roof and walls, it's time to replace your insulation.
The best loft insulation boards in terms of cost are Polystyrene (EPS) or PIR boards. Despite being costlier, rigid boards have far higher heat-retaining capabilities. Being half as thick as blanket insulation makes them very easy to install by fitting the boards in between your floor joists.
The higher the R-Value, the better the thermal performance of the insulation. The recommended level for most attics is to insulate to R-38 or about 10 to 14 inches, depending on insulation type.