How To Insulate a 100-Year Old House

( Heating, Ventilation and Air Conditioning, Insulation )

Old Houses Without Insulation

Insulating a 100-year old house that was built without insulation can be a challenging task, but it is an important one as proper insulation can significantly improve the energy efficiency and comfort of the home. Below is a research paper on the challenges and options for insulating a 100-year old house, as well as the benefits and risks of each type of insulation.

Proper insulation is essential for maintaining a comfortable and energy-efficient home. It helps to keep the heat in during the winter and out during the summer, which can save homeowners money on their energy bills and make their home more comfortable year-round. However, insulating an old house can be a challenging task due to the age and construction of the building. In this research paper, we will explore the challenges and options for insulating a 100-year old house that was originally built without insulation, as well as the benefits and risks of each type of insulation.

Challenges of Insulating a 100-Year Old House

There are several challenges that must be considered when insulating a 100-year old house. These include:

  1. The age and condition of the building: A 100-year old house is likely to have settled over time and may have structural issues that need to be addressed before insulation can be installed. Additionally, the house may have outdated wiring or plumbing that could be damaged during the insulation process.
  2. The type of construction: Older houses may have been built using different construction methods than are used today, which can make it difficult to find an insulation solution that is appropriate for the house.
  3. Accessibility: It may be difficult to access certain areas of the house, such as the attic or walls, due to the age and design of the building.
  4. The presence of hazardous materials: Older houses may contain materials that are now considered hazardous, such as lead paint or asbestos. These materials must be properly handled and removed before insulation can be installed.

Insulation Options for a 100-Year Old House

There are several options for insulating a 100-year old house. These include:

  1. Attic insulation: One of the easiest places to add insulation to an old house is the attic. There are several types of insulation that can be used in the attic, including fiberglass, cellulose, and spray foam.
  2. Wall insulation: Insulating the walls of an old house can be more challenging due to the difficulty of accessing the walls and the risk of damaging the structure of the building. Options for wall insulation include blown-in cellulose, foam board, and spray foam.
  3. Floor insulation: Insulating the floors of an old house can help to keep the heat in during the winter and out during the summer. Options for floor insulation include fiberglass, foam board, and spray foam.

Benefits and Risks of Different Types of Insulation

Fiberglass insulation is one of the most common types of insulation and is made from melted glass that has been spun into fibers. It is relatively inexpensive and easy to install, but it may irritate the skin and eyes during installation and may not provide as much insulation as other types of insulation.

Cellulose insulation is made from recycled paper products and is often treated with fire retardant chemicals. It is environmentally friendly and provides good insulation, but it can be difficult to install and may settle over time, reducing its effectiveness.

Spray foam insulation is a flexible, spray-on insulation that expands to fill gaps and crevices. It provides excellent insulation and seals air leaks, but it is expensive and may be difficult to remove if it needs to be repaired or replaced.

The Hazards of Water in Insulation

Water can have a negative impact on insulation if it comes into contact with it. Each type of insulation has its own unique characteristics that can affect its performance when it is exposed to water.

Fiberglass insulation is made from melted glass that has been spun into fibers. It is relatively hydrophobic, meaning that it does not readily absorb water. However, if fiberglass insulation becomes saturated with water, it can lose its effectiveness as an insulator. Water can also cause the fibers in fiberglass insulation to break down over time, reducing its lifespan.

Cellulose insulation is made from recycled paper products and is often treated with fire retardant chemicals to make it more resistant to moisture. However, cellulose insulation can still absorb water if it comes into contact with it, which can reduce its effectiveness as an insulator. In addition, water can cause the paper fibers in cellulose insulation to break down and decompose, reducing its lifespan.

Spray foam insulation is a flexible, spray-on insulation that expands to fill gaps and crevices. It is resistant to water and does not absorb moisture, making it an effective insulator in damp or humid environments. However, if spray foam insulation is exposed to water for an extended period of time, it can lose its structural integrity and begin to break down. This can reduce its effectiveness as an insulator and may require repair or replacement.

In general, it is important to keep all types of insulation dry to maintain their effectiveness. If insulation becomes wet, it is important to remove the water and dry the insulation as soon as possible to prevent long-term damage.

Closed Cell vs. Open Cell Insulation

Closed cell spray foam insulation and open cell spray foam insulation are both types of spray foam insulation that are applied as a liquid and expand to fill gaps and crevices. However, they have some key differences in terms of their properties and performance.

Closed cell spray foam insulation is made up of cells that are completely closed, forming a solid mass when the foam cures. It is denser and more rigid than open cell spray foam, and it has a higher R-value (a measure of thermal resistance) per inch. Closed cell spray foam insulation is also more moisture resistant and provides better structural support than open cell spray foam.

Open cell spray foam insulation is made up of cells that are only partially closed, forming a spongy mass when the foam cures. It is less dense and more flexible than closed cell spray foam, and it has a lower R-value per inch. Open cell spray foam insulation is less moisture resistant than closed cell spray foam and does not provide as much structural support.

Here are some pros and cons of closed cell spray foam insulation:

Closed Cell Insulation – pros and cons

Pros:

  • Higher R-value per inch
  • Provides structural support
  • Resistant to moisture
  • Effective at sealing air leaks

Cons:

  • More expensive than open cell spray foam
  • May be difficult to repair or remove

Open Cell Insulation – pros and cons

Here are some pros and cons of open cell spray foam insulation:

Pros:

  • More flexible and easier to work with than closed cell spray foam
  • Less expensive than closed cell spray foam
  • Effective at sealing air leaks

Cons:

  • Lower R-value per inch
  • Not as moisture resistant as closed cell spray foam
  • Does not provide structural support

In general, closed cell spray foam insulation is a better choice for areas that are prone to moisture, such as basements and crawl spaces, or for providing structural support. Open cell spray foam insulation is a good choice for filling gaps and crevices and sealing air leaks in areas that are not prone to moisture.

Rock Wool Insulation

Rock wool insulation is another option for insulating a 100-year old house. It is made from melted rock that is spun into fibers and is available in rolls or batts. Here are some advantages and disadvantages of rock wool insulation:

Pros:

  • Non-combustible and resistant to fire
  • Resistant to moisture and water vapor
  • Good soundproofing properties
  • Durable and long-lasting
  • Safe to handle and install

Cons:

  • More expensive than fiberglass insulation
  • May irritate the skin and eyes during installation
  • May not be as effective as other types of insulation in extreme temperatures

Rock wool insulation is a good choice for areas that require fire resistance, such as around wood-burning stoves or in attics with chimneys. It is also a good choice for insulating areas that may be exposed to moisture, such as basements and crawl spaces. Its good soundproofing properties make it a good choice for use in walls or floors to reduce noise. Overall, rock wool insulation is a high-performance insulation option that can provide long-lasting benefits for a 100-year old house.

Old House Design vs. Modern Insulation – is there a problem?

What are the concerns when filling those wall cavities with insulation? Weren’t the wall cavities of old houses were designed to breathe and dry out over time.

It is important to consider the potential impact of filling the wall cavities of an old house with insulation, as the cavities were originally designed to allow for ventilation and drying. If the wall cavities are not properly insulated, it can lead to problems such as moisture accumulation, mold growth, and rot. However, if the wall cavities are properly insulated, it can help to improve the energy efficiency and comfort of the home.

Adding Insulation to an Old House

Here are some concerns and best practices to consider when filling the wall cavities of an old house with insulation:

  1. Moisture: It is important to ensure that the wall cavities are dry before adding insulation. If there is moisture present in the cavities, it is important to address the source of the moisture and dry the cavities before adding insulation.
  2. Ventilation: It is important to maintain ventilation in the wall cavities to prevent moisture accumulation and mold growth. This can be achieved by adding vents or using insulation that allows for airflow.
  3. Type of insulation: The type of insulation used can impact the ability of the wall cavities to breathe and dry out. For example, foam insulation is a good choice as it is vapor permeable, allowing moisture to pass through it.
  4. Insulating techniques: There are several techniques that can be used to insulate the wall cavities of an old house, including blown-in insulation and cavity wall insulation. It is important to choose a technique that is appropriate for the age and construction of the house and to follow the manufacturer’s instructions for installation.
  5. Air sealing: In addition to adding insulation, it is important to air seal the wall cavities to prevent drafts and improve energy efficiency. This can be achieved by sealing gaps and cracks around electrical outlets and other openings in the walls.

By considering these factors and following the industry best practices, it is possible to effectively insulate the wall cavities of an old house while maintaining ventilation and preventing moisture accumulation. This can help to improve the energy efficiency and comfort of the home while protecting it from damage.

Are there types of insulation that allow air flow and the types of insulation that prevent airflow?

There are several types of insulation that allow for airflow, and these can be beneficial for preventing moisture accumulation and promoting ventilation in an old house.

Insulation for Airflow

These types of insulation include:

  1. Fiberglass insulation: Fiberglass insulation is made from melted glass that has been spun into fibers and is available in rolls or batts. It is relatively inexpensive and easy to install, and it allows for airflow due to its porous nature.
  2. Rock wool insulation: Rock wool insulation is made from melted rock that is spun into fibers and is available in rolls or batts. It is non-combustible, resistant to moisture and water vapor, and allows for airflow due to its porous nature.
  3. Cotton insulation: Cotton insulation is made from recycled cotton and is available in rolls or batts. It is environmentally friendly, allows for airflow due to its porous nature, and has good soundproofing properties.
  4. Wood fiber insulation: Wood fiber insulation is made from recycled wood fibers and is available in rolls or batts. It is environmentally friendly, allows for airflow due to its porous nature, and has good soundproofing properties.

Insulation that Stops Airflow

There are also several types of insulation that do not allow for airflow, and these can be beneficial for providing a continuous layer of insulation to prevent drafts and improve energy efficiency.

These types of insulation include:

  1. Spray foam insulation: Spray foam insulation is a flexible, spray-on insulation that expands to fill gaps and crevices. It does not allow for airflow due to its continuous, seamless nature and is effective at sealing air leaks.
  2. Foam board insulation: Foam board insulation is a rigid panel made of foam that is used to insulate walls, floors, and ceilings. It does not allow for airflow due to its solid nature and is effective at reducing thermal bridging (the transfer of heat through structural elements).

In general, it is important to consider the ventilation needs of an old house when choosing insulation. If moisture accumulation and mold growth are concerns, it may be beneficial to use insulation that allows for airflow. If energy efficiency and draft prevention are the primary goals, insulation that does not allow for airflow may be a better choice.

Should I add a vapor barrier to the outside of the house?

When adding insulation, what advantages and disadvantages result from 1) adding a vapor barrier to the exterior of the house or 2) adding faced insulation to the wall cavities, or 3) adding plastic sheet to the interior of the house over the insulation before adding drywall. 

There are several advantages and disadvantages to consider when adding a vapor barrier, faced insulation, or plastic sheeting to an old house during the insulation process. These include:

Adding a Vapor Barrier

  1. Vapor barrier: A vapor barrier is a layer of material that is installed on the exterior of the house to prevent moisture from entering the wall cavities.

Advantages:

  • Can help to prevent moisture accumulation in the wall cavities
  • Can improve the energy efficiency of the house
  • Can reduce the risk of mold growth

Disadvantages:

  • May be difficult to install on an older house due to the age and condition of the building
  • May not be necessary if the house is not prone to moisture accumulation

Adding Faced Insulation

  1. Faced insulation: Faced insulation is insulation that has a layer of paper or foil attached to one side. It is often used in walls, floors, and ceilings.

Advantages:

  • Can provide an additional layer of protection against moisture
  • Can improve the energy efficiency of the house
  • Can reduce the risk of mold growth

Disadvantages:

  • May be more expensive than unfaced insulation
  • May be difficult to install in tight spaces or around electrical outlets

Adding Plastic Sheeting

  1. Plastic sheeting: Plastic sheeting is a thin layer of plastic that is installed on the interior of the house over the insulation before drywall is added.

Advantages:

  • Can provide an additional layer of protection against moisture
  • Can improve the energy efficiency of the house
  • Can reduce the risk of mold growth

Disadvantages:

  • May be difficult to install in tight spaces or around electrical outlets
  • May not be as aesthetically pleasing as drywall

In general, it is important to consider the specific needs and concerns of an old house when deciding whether to add a vapor barrier, faced insulation, or plastic sheeting. Each option has its own unique advantages and disadvantages, and the best choice will depend on the age, condition, and construction of the house, as well as the goals of the insulation project.

If wall cavities are prone to moisture accumulation, what steps should be taken to prevent insulation from remaining wet and potentially causing wood rot and structural decay within the wall cavities?

If the wall cavities of an old house are prone to moisture accumulation, it is important to take steps to prevent the insulation from remaining wet and potentially causing wood rot and structural decay. Here are some steps that can be taken to prevent moisture accumulation in wall cavities:

Moisture Prevention Steps

  1. Address the source of the moisture: The first step in preventing moisture accumulation in wall cavities is to address the source of the moisture. This may include repairing leaks, improving ventilation, or addressing other issues that are causing moisture to accumulate in the cavities.
  2. Use moisture-resistant insulation: Choosing insulation that is resistant to moisture can help to prevent moisture accumulation in the wall cavities. Options include fiberglass insulation, rock wool insulation, and some spray foam insulation.
  3. Install a vapor barrier: A vapor barrier is a layer of material that is installed on the exterior or interior of the house to prevent moisture from entering the wall cavities. This can be an effective way to prevent moisture accumulation in wall cavities that are prone to moisture.
  4. Ensure proper ventilation: Proper ventilation is important for preventing moisture accumulation in wall cavities. This can be achieved by adding vents or using insulation that allows for airflow.
  5. Monitor and maintain the insulation: Regularly inspecting the insulation and addressing any moisture accumulation that is found can help to prevent wood rot and structural decay within the wall cavities. If the insulation becomes wet, it is important to remove the water and dry the insulation as soon as possible to prevent long-term damage.

By taking these steps, it is possible to prevent moisture accumulation in the wall cavities of an old house and protect the structure from wood rot and structural decay.

How do I find where exterior moisture penetration can occur in a house and damage insulation and the house structure?

There are several specific places and methods that can be used to check for exterior moisture penetration in a house and determine where it is occurring. These include:

Stopping moisture from the outside

Exterior Moisture Penetration

Moisture penetration from the exterior of a house can cause serious damage to the insulation and structure of the home if not addressed promptly. There are several places and methods a homeowner can use to check for potential sources of moisture penetration. Here is a guide to help you get started:

  1. Inspect the roof: One of the most common sources of moisture penetration is the roof. Check for missing, damaged, or poorly sealed shingles. Also, look for any damage to the flashing or sealant around vents, chimneys, and other openings.
  2. Check the walls: Examine the exterior walls of your home for any cracks or gaps that may allow moisture to enter. Pay particular attention to the areas around windows, doors, and corners.
  3. Look at the foundation: The foundation of your home is vulnerable to moisture penetration due to the constant contact with the ground. Check for cracks or gaps in the foundation and make sure the soil around the foundation is graded properly to direct water away from the house.
  4. Test for moisture: Use a moisture meter or a moisture detector to check for high moisture levels in areas of the home that may be prone to moisture penetration, such as basements, attics, and crawl spaces.
  5. Hire a professional: If you are unable to locate the source of moisture penetration or are unsure how to fix it, consider hiring a professional home inspector or contractor to assess the problem and recommend a solution.

By following these steps, you can help protect your home from the damaging effects of moisture penetration and maintain a healthy, comfortable living environment.