Mobile Home Insulation

Mobile Home Insulation

Replacing Mobile Home Insulation Mobile Home Belly Wrap Long-Term Savings Tips Recommended Zip Code Insulation Calculator Applies to Site Built Homes Also

Recommended Mobile Home Insulation

First, check the insulation in your homes attic, ceilings, exterior and basement walls, floors, and crawl spaces to see if it meets the levels recommended for your area. Insulation is measured in R-values—the higher the R-value, the better your walls and roof will resist the transfer of heat. DOE recommends ranges of R-values based on local heating and cooling costs and climate conditions in different areas of the nation. The map and chart below show the DOE recommendations for your area. State and local code minimum insulation requirements may be less than the DOE recommendations, which are based on cost effectiveness. For more customized insulation recommendations, check out the Zip Code Insulation Calculator. This tool provides insulation levels for your new or existing homes based on your zip code and other basic information about your home. Although insulation can be made from a variety of materials, it usually comes in four types; each type has different characteristics.

Rolls and batts—or blankets—are flexible products made from mineral fibers, such as fiberglass and rock wool.
They are available in widths suited to standard spacings of wall studs and attic or floor joists: 2x4 walls can hold R-13 or R-15 batts; 2x6 walls can have R-19 or R-21 products.

Loose-fill insulation—usually made of fiberglass, rock wool, or cellulose in the form of loose fibers or fiber pellets, it should be blown into spaces using special pneumatic equipment. The blown-in material conforms readily to the homes cavities and attics. Therefore, loose-fill insulation is well suited for places where it is difficult to install other types of insulation.
Rigid foam insulation—foam insulation typically is more expensive than fiber insulation. But it's very effective in buildings with space limitations and where higher R-values are needed. Foam insulation R-values range from R-4 to R-6.5 per inch of thickness, which is up to 2 times greater than most other insulating materials of the same thickness.

Foam-in-place insulation—this type can be blown into walls and reduces air leakage, if blown into cracks, such as around window and door frames.

Insulation Tips

Consider factors such as your climate, building design, and budget when selecting insulation R-values for homes.
Use higher density insulation on exterior walls, such as rigid foam boards, in cathedral ceilings and on exterior walls.
Ventilation helps with moisture control and reducing summer cooling bills. Attic vents can be installed along the entire ceiling cavity to help ensure proper airflow from the soffit to the attic to make homes more comfortable and energy efficient. Do not ventilate your attic if you have insulation on the underside of the roof. Check with a qualified contractor.
Recessed light fixtures can be a major source of heat loss, but you need to be careful how close you place insulation next to a fixture unless it is marked IC—designed for direct insulation contact. Check your local building codes for recommendations. See Lighting for more about recessed cans.
As specified on the product packaging, follow the product instructions on installation and wear the proper protective gear when installing insulation.

Long-Term Savings Tip

One of the most cost-effective ways to make homes more comfortable year-round is to add insulation to your attic.
Adding insulation to the attic is relatively easy and very cost effective. To find out if you have enough attic insulation, measure the thickness of the insulation. If it is less than R-30 (11 inches of fiber glass or rock wool or 8 inches of cellulose), you could probably benefit by adding more. Most U.S. homes should have between R-30 and R-60 insulation in the attic. Don't forget the attic trap or access door.
If your attic has enough insulation and your home still feels drafty and cold in the winter or too warm in the summer, chances are you need to add insulation to the exterior walls as well. This is a more expensive measure that usually requires a contractor, but it may be worth the cost if you live in a very hot or cold climate. If you replace the exterior siding on any homes, you should consider adding insulation at the same time.
You may also need to add insulation to your crawl space or basement. Check with a professional contractor.

New Construction

For new homes in most climates, you will save money and energy if you install a combination of cavity insulation and insulative sheathing. Cavity insulation can be installed at levels up to R-15 in a 2 in. x 4 in. wall and up to R-21 in a 2 in. x 6 in. wall. The insulative sheathing, used in addition to this cavity insulation, helps to reduce the energy that would otherwise be lost through the homes wood frame. The table below shows the recommended combinations. For example, in Zone 5, you could use either a 2x4 wall with R-13 or a 2x6 wall with R-21. For either of those two walls, you should also use an inch of insulative sheathing that has an R-value of R-5 or R-6.

Today, new products are on the market that provide both insulation and structural support and should be considered for new homes construction or additions. Structural insulated panels, known as SIPs, and masonry products like insulating concrete forms are among these. Some home builders are even using an old technique borrowed from the pioneers: building walls using straw bales. Check online at for more information on structural insulation.

Radiant barriers (in hot climates), reflective insulation, and foundation insulation should all be considered for new homes construction. Check with your contractor for more information about these options. Look at Insulation R value zone map below.

Insulation R Values Zone Map Picture

All of Alaska in Zone 7 except for the following boroughs in Zone 8:

Northwest Arctic
Southeast Fairbanks
Fairbanks N. Star
Wade Hampton
North Slope

Zone 1 includes:

Puerto Rico
Virgin Islands

*These recommendations are cost-effective levels of insulation based on the best available information on local fuel and materials costs and weather conditions. Consequently, the levels may differ from current local building codes for homes.

Cost Effective Insulaton Values

Cost Effective Insulation Values Picture

Mobile Home Insulation and Belly Wrap

Any gaps or damage in the under floor mobile home insulation can be repaired as you would any homes, with minor exceptions. Simply install roll type insulation of sufficient "R" value in between the floor joists and affix in place with insulation support wires. Use the insulation that has the facing on it. The fabric on the underside of manufactured homes is generally called "belly wrap", some homes have a hard fiber board called "belly board" You need to either then pull the belly wrap cover over the new insulation or if that is not possible you can leave the new insulation exposed as it would be in site built homes. I do recommend repairing the belly wrap. Belly wrap to fix any damaged areas can be purchased from a mobile home supply. Belly wrap is available in lots of sizes and is not expensive. Here is a great place to get Belly Board Wrap. They have all the supplies you need to repair the belly wrap and board. I have also seen the underside of the home closed off with foam board after insulating. This may be over kill, unless you are in live in extreme conditions. This is also a good time to insulate pipes or duct work. Be sure to correct the reason for damage before doing the repair, such as water leaks or critters. The belly wrap is used to prevent moisture under homes from getting up into the under side of the floor and cause rot and mildew. I suggest putting down a vapor barrier under the home, such as sheet plastic. Be sure to check with local regulations.

Replacing Mobile Home Insulation

I removed all the belly wrap and blown in insulation under my double wide and replaced it with batt insulation, I also used insulated flex duct work with no problems. That was 5 years ago and still no problems. If you live in a climate with very cold winters I would recommend that you insulate the homes water pipes with pipe insulation that can be found at your local home improvement store and cover all your pipes before installing the batt insulation. These are the long foam sleeves you place over your pipes. For over kill you can wrap the pipes in aluminum foil before you put the foam sleeves in place. Be sure to cover everything with the sleeves and leave no gaps using quality duct tape to make the foam sleeves stay in place. Select the highest R value for the insulation batts that you can afford. There is a data sheet in your mobile home somewhere that has these R values, usually found in the laundry area cabinets and it has a zone map, also called a data plate, (see below for picture of mobile home data plate) with other info on it like the serial number. It will tell you the homes wall, floor and ceiling insulation values. Match or exceed these values. I left no dead air space when I did mine. The batt insulation tells you on the paper side whether to place the paper side towards the living space or not follow those instruction. Be sure to cover the homes pipes with the insulation where you can, if there is any dead air space because of that it should be fine. Determine how much square feet you have and buy the insulation accordingly. The belly wrap can be replaced, if you so desire after re-insulating and is available through some of the mobile home supply vendors advertising on my site and is cheaper than you might think. However that is a lot of work. Don't forget the wire hangers to hold the insulation in place. You also may want to consider using a heat tape to further prevent problems in the area the pipes cannot be adequately insulated, like where the water line come up into the homes interior, follow the package instructions on the heat tape. Lastly airtight underpinning is important. There are even insulated skirting underpinning panels you can use.

Here is anatomy view of a single wide mobile home showing the placement of insulation. Double wide homes are very similar.

Anatomy View of a single Wide Mobile Home Picture

Mobile Home Data Plate

Mobile Home Data Plate Picture