In most standard vented attics, insulation should not touch the underside of the roof deck. You need an unobstructed air gap of at least 1 1 to 2 2 inches between the insulation and the roof sheathing.
Yes, you can insulate the underside of your roof, but doing so converts your attic from a vented "cold" space to an unvented "conditioned" space. This requires careful moisture control to prevent roof rot. You can accomplish this in two primary ways:
The 25% Rule in roofing serves as a guideline for both homeowners and contractors when planning roofing projects. Basically, it means that if more than 25% of your roof's surface needs repairs, it's often wiser to contemplate a full replacement rather than patchwork.
Specifically, it mentions that a minimum ventilation gap of 50 mm (2 inches) should be maintained between the insulation and the roofing membrane for pitched roofs. However, some insulation types, such as spray foam, are designed to work without requiring an air gap.
Looking across your attic, if the insulation is level with or below the attic floor joists, you probably need to add more insulation. If you cannot see any of the floor joists because the insulation is well above them, you probably have enough, and adding more insulation may not be cost-effective.
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.
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.
Insulating a 2,000 sq. ft. attic costs between $2,000 and $9,000, with most homeowners paying around $3,600 to $5,800 for professional installation. The wide price range depends on the type of insulation, labor rates, and whether old insulation requires removal.
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.
10 Insulation Installation Mistakes to Avoid
To tell if a roofer is lying, watch out for high-pressure sales, suspiciously low bids, and demands for large upfront cash payments. Honest roofers provide clear, detailed contracts and verifiable credentials. Always check their local license, avoid signing contingency agreements before fully committing, and get a second opinion.
Generally, the late fall and winter months can be the most cost-effective times to schedule a roof replacement. This is typically the slow season for roofing contractors, and as business wanes, you might find that they are more willing to negotiate on price.
There are specific phrases that consistently cause problems. Saying “my roof was already damaged before the storm” gives the adjuster a reason to classify damage as pre-existing. Admitting fault with “I think it might be my fault” shifts liability onto you.
What time of year is Insulation cheapest?
Closed cell spray foam is rigid once set. It is a better thermal insulator and was previously sold to stabilise failing roofs. But if it has been used inappropriately or installed poorly, it might put stress on timbers, restrict air circulation and put them at risk of decaying.
Tar paper serves several critical functions that shouldn't be overlooked: Waterproofing: In our experience, it acts as a secondary barrier against moisture, ensuring that any water sneaking past your shingles doesn't compromise the wood beneath.
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.
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.
You might think that spotting one mouse means you only have one mouse. This rarely happens. Mice live in family groups and reproduce quickly. If you see one mouse during the day, it usually means the hidden population has grown large enough that they're competing for food and space.
Fall is an ideal time for insulation.
Adding insulation before winter can help reduce heating bills significantly. Spring is another excellent option for installation. It provides an opportunity to prepare your home for summer's heat. Insulating in spring can keep your home cooler and reduce air conditioning costs.
For most attics, blown insulation is better than rolled insulation. Blown-in is ideal for older homes or attics with irregular framing, as the machine-blown material conforms tightly around pipes, wires, and joists. Rolled insulation is better for brand-new, empty attics with no obstructions.
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.
Homebuyers: Look for Signs of Poor Maintenance
To check your home's insulation, start by using a thermal imaging camera (like a FLIR device attached to your smartphone) to find hot or cold spots. Alternatively, turn off the power, remove an electrical outlet cover on an exterior wall, and visually check the wall cavity with a flashlight.
Walls, floors and ceilings should feel warm and dry to the touch in your home. An indication that there is not enough insulation can be drywall or paneling feeling damp or cold. Conversely, the walls outside of your home should feel cold because insulation stops the heat from escaping.