You generally do not need to replace 20-year-old insulation unless it is damaged, damp, or heavily infested by pests. Most fiberglass and cellulose insulation can last 20 to 30 years. Instead of a costly full replacement, it is usually much more cost-effective to simply add a new layer of blown-in insulation on top to bring your attic up to current energy efficiency codes.
Insulation only needs to be replaced if it has been damaged by water, contaminated by pests, or compressed. Otherwise, it typically lasts the lifetime of your house (80–100 years for fiberglass). Instead of replacing old insulation, you can usually just "top it up" with a fresh layer.
Installing new insulation over old is a viable option for keeping your home warm in the winter and cool in the summer. However, the current insulation must be in good condition. It's vital that a professional insulation technician inspect your current insulation before adding another layer.
Look for the following common signs:
Poor insulation forces your HVAC to work overtime, resulting in skyrocketing energy bills, uneven room temperatures, and drafty areas. Look for warning signs like cold walls, frozen pipes, and frequent condensation or mold growth, which indicate moisture is collecting on uninsulated surfaces.
Should I do the project myself or hire a contractor? If your attic is accessible and not too difficult to move around in, and you enjoy tackling bigger home improvement projects, attic insulating may be a good DIY project. Otherwise, consider finding a contractor to complete the project for you.
Mice are curious and always searching for safe, snug, and warm nesting sites. Attics filled with blown-in insulation provide an excellent option–from the mice's point of view. As long as there is a ready food source. Mice are omnivorous and will eat and chew on almost anything including wood and electrical wires.
Because spray foam can trap moisture, hide the condition of the roof, make it difficult for surveyors to inspect, which means risks like timber decay, dry rot, and not forgetting increased fire risk. If you've got it or you're buying a property that does, this is something you need to know upfront.
What time of year is Insulation cheapest?
Yes, insulation is tax-deductible in the form of a federal tax credit, specifically the Energy Efficient Home Improvement Credit (Section 25C). You can claim 30% of the cost of insulation and air sealing materials, up to a maximum annual credit of $𝟏,𝟐𝟎𝟎.
The desire of mice to sharpen their teeth is a common phenomenon in rodents, and they find this process particularly attractive in thermal insulation and any other building material. Attempts to obtain food – even inedible insulation materials can be chewed through by mice in the hope of obtaining food.
How age affects insulation performance: Older homes built in the 1970s or earlier need to have their insulation replaced, especially if the insulation hasn't been replaced since. Common types of insulation in older homes include old fibreglass batts, cellulose, rockwool, foil, sawdust, wool, and polyester.
Fiberglass particles typically stay in the lungs for a relatively short period, ranging from a few days to a few weeks. Unlike asbestos, modern fiberglass is engineered to dissolve or break down, allowing the body’s immune cells (macrophages) to digest and clear the fragments.
Older homes are generally not better insulated than new construction. Built before modern energy codes existed, homes constructed prior to the mid-20th century typically have little to no insulation. While they may feature thicker walls, modern homes use advanced materials and stringent air-sealing techniques to maximize energy efficiency.
You do not always need to remove old insulation. If it is dry, undamaged, and free of pests, it is often perfectly fine (and more budget-friendly) to simply add a new layer on top to boost your home’s energy efficiency.
Attic insulation installation ranges from $1.50 sq/ft. to $2.45 sq/ft. The average cost of attic insulation installation is $1.80 sq/ft.
Choosing the best time to insulate your home largely depends on your circumstances and needs. However, it's generally recommended to install insulation during the spring or early summer months. This timing allows you to prepare your home for the extreme temperature swings of summer and winter.
The Amish control mice through non-chemical, self-sustaining methods, relying on active trapping, natural scent repellents, and structural exclusion. Rather than using commercial poisons, they focus on physical barriers and natural predators to keep rodent populations in check.
While traditional fiberglass and cellulose are soft and easy for mice to tunnel through, true "rodent-proof insulation" relies on dense, unpalatable materials like mineral wool, combined with solid physical barriers to block entry points.
Potential problems with spray foam insulation
reduce air circulation and ventilation within a roof space. lead to dampness and condensation on the underside of a roof because it forms an air barrier and stops moisture from escaping. place timber-framed roofs at risk of decay.
These factors can create a task that is too much for a homeowner to take on alone. Another reason we recommend working with a professional is for air-sealing. Yes, you could technically install blown-in insulation yourself. But if you work with a professional contractor, you could have your attic air-sealed.
For a 1,500-square-foot attic, expect to spend around $1,500 to add cellulose insulation professionally. DIY fiberglass installation may cost $500–$750 in materials. Get multiple quotes when hiring an insulation company.
The 7 and 7 rule for attic conversions refers to the common requirement that finished attics be at least 7 feet wide and 70 square feet, with 7-foot ceilings over at least half. Keep in mind that this is a general guideline. Local building codes may have stricter requirements that supersede this rule.