Loft Insulation Calculator

FAQs

How do I calculate how much loft insulation I need? To calculate the amount of loft insulation you need, consider the desired insulation thickness and your loft's area. Divide the desired thickness by the existing thickness to determine the additional insulation needed.

How thick should my loft insulation be? The recommended loft insulation thickness varies, but for a typical loft, aim for around 10-12 inches (25-30 cm) of insulation.

How much insulation do I need for 1000 square feet? The amount of insulation needed for 1000 square feet depends on the desired thickness. For example, if you're aiming for 12 inches of insulation, you'd need 1000 square feet x 1 foot = 1000 cubic feet of insulation.

What is the recommended loft insulation? The recommended loft insulation thickness is generally around 10-12 inches, but it depends on your climate and location.

Can loft insulation be too thick? Excessively thick loft insulation can cause moisture issues and reduce ventilation. It's important to maintain a balance for proper insulation performance.

Can you have too much insulation in your loft? Yes, too much insulation can lead to trapped moisture and ventilation problems, impacting insulation effectiveness.

Should loft insulation go right to the edge? Loft insulation should generally be laid between the joists, leaving a gap at the edges to allow air circulation and prevent condensation.

How much air gap for loft insulation? An air gap of about 50 mm (2 inches) should be left between loft insulation and the roof to ensure proper ventilation and prevent moisture buildup.

Do you need an air gap for insulation? Yes, an air gap between insulation and the roof is necessary to prevent condensation and maintain ventilation.

Can you lay loft insulation over joists? Loft insulation is typically laid between the joists to maintain airflow and prevent moisture. Avoid compressing insulation by laying boards over joists.

Is it OK to insulate roof rafters? Insulating roof rafters can help create a warmer loft space, but proper ventilation and moisture control are essential to prevent issues.

How much difference does thicker loft insulation make? Thicker loft insulation can significantly improve energy efficiency by reducing heat loss and making your home more comfortable.

Should I remove old attic insulation before adding new? Removing old insulation may be necessary if it's damaged or contaminated. Otherwise, adding new insulation over old layers is acceptable.

How much does 1 bag of insulation cover? The coverage of 1 bag of insulation depends on the type and brand. Read the product label for coverage specifications.

How much is 1200 sq ft of insulation? To determine the amount of insulation needed for 1200 sq ft, consider the desired thickness and insulation type. Check the product label for coverage details.

Does more loft insulation make a difference? Yes, more loft insulation can significantly improve energy efficiency, reducing heat loss and lowering energy bills.

Which is better attic insulation blown or rolled? Blown insulation offers better coverage in irregular spaces, while rolled insulation is easier for DIY installation in standard attics.

Should loft insulation be pushed up to the eaves? Loft insulation should not be pushed up to the eaves to ensure proper ventilation and prevent condensation.

Does loft insulation go over or between joists? Loft insulation typically goes between the joists to maintain ventilation and prevent moisture buildup.

How often should you replace loft insulation? Loft insulation can last for several decades, but factors like damage or degradation may necessitate replacement.

Should my loft be cold? A properly insulated loft should be warmer than an uninsulated one, but it may not be as warm as the rest of the house.

Can you put new insulation on top of old insulation? Yes, adding new insulation on top of old layers is possible as long as the space is properly prepared.

Is R60 attic insulation worth it? Attic insulation with an R60 value can provide excellent energy efficiency and comfort, especially in colder climates.

Is it OK to stack insulation? Stacking insulation can compress lower layers, reducing their effectiveness. It's better to lay insulation evenly.

Where not to put loft insulation? Avoid blocking vents or recessed light fixtures with loft insulation, as this can cause ventilation and fire hazards.

Should loft insulation foil side up or down? Foil insulation should face downward to prevent moisture accumulation on the foil surface.

Where should you not put insulation in the attic? Avoid placing insulation in front of soffit vents, as this can block proper ventilation.

Should insulation touch the roof? Insulation should not touch the roof to allow proper ventilation and prevent moisture buildup.

Can you double up foil insulation? Doubling up foil insulation can trap moisture and is not recommended. Follow manufacturer guidelines.

Does an air gap have an R-Value? An air gap itself does not have a defined R-value, but it can enhance insulation performance by providing an extra barrier.

What happens if you don't install an air gap? Without an air gap, moisture can accumulate and ventilation may be compromised, leading to potential issues.

What happens if you don't have an air gap? Without an air gap, moisture can lead to condensation and mold growth, potentially damaging the insulation and structure.

What is the minimum gap between insulation? A minimum gap of about 50 mm (2 inches) is recommended between insulation and the roof for proper ventilation.

Is loft insulation OK for stud walls? Loft insulation is designed for horizontal spaces like attics and lofts, not vertical applications like stud walls.

Can cables go under loft insulation? Cables should not be covered by loft insulation, as they may overheat. Maintain a gap around cables for safety.

Can you walk on loft insulation? You can walk on loft insulation, but it's better to lay boards or panels over the joists for safe access.

What is the best insulation for loft rafters? Rigid foam insulation is often used for insulating loft rafters due to its thermal resistance and moisture resistance.

Is it better to insulate rafters or ceiling? Insulating rafters creates a warm loft space, while insulating the ceiling prevents heat from escaping the living areas.

What is the best insulation for roof rafters? Polyisocyanurate or spray foam insulation is commonly used for insulating roof rafters due to their high R-values and performance.

How much warmer does loft insulation make a house? Proper loft insulation can make a house significantly warmer, reducing heat loss and improving comfort.

How much will extra loft insulation save me? Adding extra loft insulation can lead to substantial energy savings by reducing heating costs.

Is attic insulation more important in winter or summer? Attic insulation is important year-round. It keeps heat in during winter and prevents heat gain in summer.

Do you need ventilation in attic after you insulate? Yes, proper attic ventilation is crucial after insulation to prevent moisture buildup and maintain a healthy attic environment.

Does attic insulation become less effective over time? Attic insulation can degrade over time due to settling or damage, leading to reduced effectiveness.

How many bags of blown insulation do I need for 1000 square feet? The number of bags depends on the desired thickness and the product's coverage per bag. Check the product label for guidance.

Is 2 inches of insulation enough? 2 inches of insulation may not provide adequate thermal resistance. Aim for a higher R-value for better energy efficiency.

How many bags of blown insulation do I need for my attic? Calculate the number of bags by dividing your attic's area by the coverage area specified on the insulation product's packaging.

Is it cheaper to spray foam yourself? Spray foam insulation is best applied by professionals due to its specialized equipment and potential complexities.

What is the cheapest attic insulation? Fiberglass batt insulation is often considered one of the more affordable options for attic insulation.

Can I spray foam insulation myself? Spray foam insulation is best left to professionals due to its technical requirements and potential hazards.

What is the best thickness for loft insulation? Aim for around 10-12 inches of loft insulation thickness for optimal energy efficiency.

What is the cheapest way to insulate a loft? Adding more insulation to an existing loft is cost-effective. DIY installation of rolled fiberglass insulation is also budget-friendly.

Can you put too much insulation in attic? Excessive insulation can lead to ventilation problems and moisture buildup, so it's important to strike a balance.

Should I remove old attic insulation before adding new? If the old insulation is in good condition, it's possible to add new insulation on top. Otherwise, removing it may be necessary.

What are the disadvantages of blown-in insulation? Blown-in insulation can settle over time, reducing its effectiveness. It may also be more challenging to install properly.

Should loft insulation go right to the edge? Loft insulation should not go right to the edge to allow for proper ventilation and prevent condensation.

How much gap between eaves and loft insulation? Leave a gap of about 50 mm (2 inches) between the eaves and loft insulation for ventilation.

Should loft insulation be pushed up to the eaves? No, loft insulation should not be pushed up to the eaves. Leave a gap for ventilation and prevent moisture buildup.

How should loft insulation be laid? Loft insulation should be laid between the joists, ensuring an even layer without compression, to maintain effective coverage.

How do I know if my loft insulation is bad? Signs of bad loft insulation include uneven temperatures, drafts, and increased energy bills. Inspect for wear or damage.

Is it worth changing loft insulation? If your current loft insulation is inadequate or damaged, upgrading to higher-quality insulation can be worth the investment.

How do I keep my loft warm in the winter? To keep your loft warm in winter, ensure proper insulation, seal gaps, and consider using thermal curtains.

Does loft insulation keep cold out? Yes, loft insulation helps prevent heat loss, keeping the cold air out and the indoor space warmer.

Does stacking insulation double the R-value? Stacking insulation does not double the R-value. The overall R-value depends on the sum of the insulating materials' R-values.

Can you put too much insulation? Excessive insulation can lead to ventilation problems and moisture buildup, so it's important to follow recommended guidelines.

How many inches of insulation do I need for R60? The recommended insulation thickness for achieving an R60 value varies depending on the type of insulation used.

How many inches is R60 attic insulation? The insulation thickness needed for an R60 value depends on the type of insulation material and its specific R-value per inch.

Can you put 2 layers of insulation in attic? It's possible to use two layers of insulation to achieve the desired R-value, but the first layer should be evenly distributed.

How do you know if you have too much insulation? If your home becomes excessively hot or humid, or if you experience ventilation issues, you may have too much insulation.

How close to edge should loft insulation? Leave a gap of about 50 mm (2 inches) between the loft insulation and the roof edge to ensure proper ventilation.

What are the do's and don'ts of loft insulation? Do: Use proper materials, maintain ventilation, seal gaps. Don't: Block vents, compress insulation, ignore signs of damage.

Does it matter which way insulation faces? Yes, the correct orientation of insulation matters. Vapor barriers and reflective surfaces should face the appropriate direction.

Can you double up foil insulation? Doubling up foil insulation can trap moisture and is not recommended. Follow manufacturer guidelines.

Should there be a gap in the attic with the insulation? A gap between insulation and the roof is recommended to allow for ventilation and prevent moisture issues.

Which way should insulation face in attic? Insulation should face the living space to retain heat and prevent moisture from reaching the cold surfaces.

Should you leave a gap between insulation and roof? Yes, a gap between insulation and the roof is essential for proper ventilation and moisture prevention.

Can you put insulation directly against roof? Insulation should not touch the roof directly. Leave a gap for ventilation and to avoid trapping moisture.

What is the disadvantage of foil insulation? Foil insulation may not be as effective in cold climates and requires proper installation to prevent condensation.

Should foil on insulation face in or out? Foil insulation should face outward to reflect radiant heat away from the building, preventing it from entering.

What is the R-value of a 1 inch air gap? The R-value of a 1-inch air gap is relatively low, around R-1 to R-2, as air gaps provide limited insulation.

What is the R-value of 1/2 air gap? The R-value of a 1/2-inch air gap is minimal, contributing only a small amount of insulation.

What is the minimum air gap behind insulation? A minimum air gap of about 1 inch is recommended for insulation to allow for some ventilation and prevent moisture buildup.

What is the minimum air gap required? The minimum air gap required can vary depending on building codes and insulation materials, but about 1 inch is common.

How high does an air gap need to be? An air gap of about 1 inch is a common recommendation, but consult local building codes and insulation guidelines.

How do you know if you need an air gap? An air gap is needed to prevent moisture buildup and ensure proper ventilation, particularly when installing insulation.