Insulating Your Camper: Is Foam Board A Good Idea?

Insulating your camper with foam board is a great way to keep your vehicle warm in the winter and cool in the summer. Foam board insulation is a rigid panel made of polystyrene, polyisocyanurate, or polyurethane. It has a lower R-value than other types of insulation, but it can last for a long time without losing quality. To insulate your camper, you can cut and install the foam board inside the walls and roof of your vehicle. However, this process can be challenging and expensive, so it is recommended to seek professional help or opt for other insulation methods if you are not confident in your abilities.

The best foam board for camper insulation

When it comes to choosing the best foam board for your camper insulation, there are several factors to consider. The insulation's effectiveness, ease of installation, health and environmental impact, cost, and fire resistance are all important considerations. Here are some options for the best foam board insulation for your camper:

Polyiso Foam Board

Polyiso foam board, also known as PIR (Polyisocyanurate) board, is a popular choice for camper insulation. It has a high R-value, indicating superior insulating properties. PIR boards are made by blending different materials to create a rigid, single-core of Polyisocyanurate, which is then sandwiched between two layers of high-performance aluminium foil. This construction provides a radiant heat barrier and improves the board's durability. PIR boards are also moisture-resistant and have a low environmental impact, making them a more sustainable option than other types of foam boards. They are widely available in DIY stores and relatively easy to install, although custom installations can be expensive.

XPS Foam Board

XPS (Extruded Polystyrene) foam board is another option for camper insulation. It is made through an extrusion process where plastic resin and other ingredients are melted and then continuously extruded through a die, resulting in closed-cell rigid insulation. XPS foam board is moisture-resistant, preventing mould growth. It also has superior long-term strength and durability due to its closed-cell structure, making it resistant to the vibrations of the van while driving. XPS boards are typically more affordable than PIR boards, but they have a higher environmental impact due to the manufacturing process.

EPS Foam Board

EPS (Expanded Polystyrene) foam board is similar to XPS but with a slightly different manufacturing process. EPS boards are made by moulding small foam beads and then applying heat or steam to expand and fuse them together. However, EPS boards have small voids between the beads, making them less effective at preventing water penetration. They are also less durable and may degrade over time, especially when exposed to vibrations during travel. EPS boards are typically the most affordable option among foam boards, but they have a lower R-value and may not provide the same level of insulation as PIR or XPS boards.

When choosing the best foam board for your camper insulation, consider the specific needs of your camper and your budget. PIR boards offer superior insulation and durability but come at a higher cost. XPS boards are a good alternative if you're looking for something more affordable and moisture-resistant, but they have a higher environmental impact. EPS boards are the most budget-friendly option, but they provide less insulation and are more susceptible to moisture and degradation over time.

How to install foam board insulation

Foam board insulation is a skill worth acquiring for any DIY enthusiast. The lightweight boards are typically 4 feet by 8 feet and range from 0.5 to 2 inches thick. Before you begin, you must choose the right type of foam board insulation for your project, such as EPS (expanded polystyrene) or XPS (extruded polystyrene).

Step 1: Measure and Cut the Boards

First, determine the amount of insulation you need using a tape measure. For an 8-foot-high wall, a 4-foot by 8-foot sheet can be installed without trimming. For shorter or taller walls, you will need to cut multiple boards accordingly. Wall studs typically measure 12, 16, or 24 inches, so you only need to trim the boards lengthwise. For irregularly shaped walls, use a sharp knife to trim each sheet. To cut the boards, take a sharp blade and cut at an aggressive angle straight through the insulation panels.

Step 2: Hang the Rightly Sized Boards

You can hang the foam boards on the wall using either construction adhesive or button cap nails. Ensure that the spacing is correct to fit the stud. The sheets placed side by side should be connected to a single stud, which will strengthen the wall laterally. Install the foam boards vertically if the drywall is placed horizontally to avoid unwanted cracks or intersections.

Step 3: Apply Joint Tape (Optional)

Sealing the joints is optional, but it is recommended to improve the insulation.

Step 4: Install Foam Board Inside the Wall

If your walls are thicker than the standard 2"x4" or do not meet the building code-recommended R-value, you will need to install foam board inside the wall. Measure the spacing between the studs, typically 16" or 24" centres, and cut the foam board accordingly. You may need to use construction adhesive to glue multiple layers of foam sheets together or use interior wall insulation panels.

Step 5: Choose Your Installation Method for Cement or Masonry Block Walls

When installing foam boards on a cement or masonry block wall, you can choose to attach the boards directly to the block or use furring strips. It is recommended to attach the boards to furring strips for better insulation, as an air gap between the board and the wall improves its performance.

Step 6: Install the Furring Strips

Use masonry nails and a pneumatic nail gun to install the furring strips, placing them on consistent centres from the floor to the ceiling. Construction adhesive or nails can be used to attach the strips, ensuring a 3/4" gap between the foam board and the block wall. This gap will protect the foam from moisture.

The cost of foam board insulation

Cost Factors

• Type of Foam Board: The cost of foam board insulation can vary depending on the type of material used. For example, XPS foam board is generally more expensive than EPS foam board. Polyiso (PIR) foam board, known for its high R-value and environmental friendliness, tends to be pricier than other options.
• Thickness: The thickness of the foam board also influences the cost. Thicker boards provide better insulation but come at a higher price.
• Quantity: Buying in bulk can often result in savings. Many retailers offer discounted prices when purchasing 10 or more boards.

Pricing Examples

• Owens Corning FOAMULAR NGX Insulating Sheathing: 0.5" x 4' x 8' SE R-3 XPS Rigid Foam Board Insulation. Buy 10 or more for $17.07 each.
• Owens Corning FOAMULAR NGX F-150: 1" x 4' x 8' SSE R-5 XPS Rigid Foam Board Insulation. Buy 10 or more for $28.77 each.
• R-Tech: 1" x 48" x 8' R-3.85 Insulating Sheathing. Buy 10 or more for $28.77 each.
• Owens Corning FOAMULAR 150: 1" x 4' x 8' R-5 Scored Square Edge Rigid Foam Board Insulation Sheathing. Buy 10 or more for $14.38 each.
• Owens Corning FOAMULAR NGX: 1" x 2' x 2' R-5 Project Panel XPS Rigid Foam Board Insulation. Buy 10 or more for $48.57 each.
• Owens Corning FOAMULAR 150: 2" x 4' x 8' R-10 Scored Square Edge Rigid Foam Board Insulation Sheathing. Buy 10 or more for $48.57 each.
• Owens Corning FOAMULAR 150: 2" x 4' x 8' R-10 Unfaced Square Edge Insulation Sheathing. Buy 10 or more for $58.47 each.
• Owens Corning FOAMULAR NGX F-250: 2" x 4' x 8' SSE R-10 XPS Rigid Foam Board Insulation. Buy 10 or more for $58.47 each.
• RMAX Pro Select R-Matte Plus-3: 0.5" x 48" x 8' R-3.2 ISO Rigid Foam Board Insulation. Buy 10 or more for $25.09 each.
• Owens Corning FOAMULAR: 1/4" x 4' x 50' R-1 Fanfold Rigid Foam Board Insulation Sheathing. Buy 10 or more for $9.88 each.
• 3/4" x 1.25' x 4' R-2.65 Polystyrene Panel Insulation Sheathing: 6-Pack. Price not specified.
• STYRO Industries FP Ultra Lite: 2" x 2' x 4' Stucco Grey Foundation Panel. Price not specified.

Additional Costs to Consider

When insulating a camper with foam board, there are additional costs to consider beyond the foam board itself. These include:

• Adhesives: You will need to purchase appropriate adhesives to attach the foam board to your camper. Foil HVAC tape is recommended for its ability to withstand cold temperatures and leave no residue when removed.
• Tools: You may need to purchase or rent tools for cutting and installing the foam board, such as knives, saws, or staple guns.
• Other Materials: Depending on the complexity of the project, you may require additional materials such as duct tape, tent stakes, markers, or protective gear.
• Labour: If you choose to hire a professional to install the foam board insulation, you will need to factor in labour costs, which can vary depending on the size and complexity of the project.

Pros and cons of foam board insulation

Foam board insulation is a great alternative to fibreglass batt insulation. It has a higher R-value per inch of thickness, is resistant to moisture and is easy to work with. Here are some pros and cons of foam board insulation to help you decide if it's the right choice for your camper.

Pros:

• It is a terrific alternative to fibreglass batt insulation, which is commonly found in homes.
• It has a higher R-value per inch of thickness, meaning it provides better insulation.
• It is resistant to moisture, making it a good choice for areas that may get wet, such as an exterior foundation, basement or house wrap.
• It is easy to work with and can be cut with a circular saw or utility knife.
• It is available in standard sizes (4x8 sheets) and smaller sizes, with thicknesses ranging from 1/4 inch to two inches.
• It is durable and lightweight, with convenient dimensions of 2'x8' and 4'x8'.
• It can be used to protect slabs, control the flow of vapour and moisture, and keep wall cavities dry.
• It can reflect heat into a room, boosting thermal resistance.
• It is versatile and can be used in a variety of applications, including below grade, on the warm side of a wall, and on a wall's exterior.
• It is simple to install and can be cut to size and set in place with an adhesive, screws and washers, or special spray foam.

Cons:

• It is more expensive than traditional batt insulation, so it may not be suitable for all budgets.
• It may not be easily reusable or transportable, especially if you plan to move your camper often.
• It may not be suitable for all climates, as its performance can deteriorate in very cold temperatures.
• It has a higher embodied carbon content and can be less environmentally friendly than other types of insulation, such as PIR boards.
• It may not be suitable for all areas of a camper, and you may need to use other types of insulation in combination with foam board.

Other insulation options

There are several other options for insulating your camper van, including:

• Reflective Bubble Foil Insulationpolythene bubble membrane with two reflective aluminium foil surfaces. While it is effective at reflecting radiant heat, it should not be installed directly onto the van's surface as it will not have any effect. Instead, it should be placed at least 1 inch (2.5 cm) away from the van's panels to act as a radiant barrier. It can also be used as window coverings to shield your van from incoming sunlight and keep it cool during hot days.
• Polyurethane Spray Foam Insulation: This type of insulation is applied directly onto the van's walls using a spray canister. It expands to form an airtight barrier that insulates against temperature, moisture, and noise. It is lightweight and affordable but can be challenging to install, especially for inexperienced individuals.
• Fibreglass Wool Insulation: Fibreglass wool is composed of fine glass fibres that can be cut to shape and stuffed into hard-to-reach places. It is affordable, widely available, and easy to install. However, it absorbs moisture, which can lead to mould growth and deterioration over time. It also poses potential health risks, as inhaling tiny fibreglass particles can be harmful.
• Rockwool Insulation: Rockwool is a rock-based mineral fibre insulation made from Basalt rock and recycled Slag. It has similar thermal properties to fibreglass but is more durable and better at dealing with moisture. It also has excellent acoustic properties, effectively trapping soundwaves and dampening vibrations. However, it is more expensive than fibreglass and requires protective gear during installation due to potential health risks.
• Sheep Wool Insulation: Sheep wool is a natural and sustainable insulation option that effectively traps air, providing a thermal barrier. It can absorb and wick away moisture, resist mould and mildew, and has excellent sound-deadening properties. However, it has a lower R-value per 100mm than some other insulation materials, so more thickness is needed to achieve the same insulating effect.

Frequently asked questions