Hugh Cairns: Mobile home inspections


Mobile home inspections are approached by home inspectors in a manner that diverges from traditional site-built housing inspections because mobile home structures are designed and constructed quite differently. When we build a traditional site based home, the construction is generally inspected by the authority of jurisdiction. Since mobile homes are factory built, most often in a uniform fashion at a remote location, they are built to standards approved by the Canadian Standards Association (CSA). Mobile homes have specific construction and design standards to assure their durability, quality and most importantly, safety. Mobile homes are constructed on a non-removable steel frame and transported building sites on wheels.

Since the 1972, mobile homes manufactured in Canada have been required to carry CSA certification. CSA certification is usually proven on older mobile homes as an important decal placed on the exterior cladding of the home. It’s important not to remove or deface the decal, without it, its value may be diminished. On newer homes the CSA sticker may be located at the electrical panel.

There are many advantages of purchasing a mobile home, many of which are easily explained by your realtor. Most people tend to be attracted to their attractive pricing and value. Lower monthly payments, insurance costs, and perhaps even faster equity build-up make them a smart buy. I find that they are generally reliable and uncomplicated resulting in economical maintenance, repairs and upgrades.

Mobile home inspections aren’t all about picking them apart, making sure that things are right is just as important. Should the mobile home inspection yield a problem, it can usually be resolved for much less expense than a traditional house. Knowing what problems are present, if any, will get you off to a great start.

Inspecting mobile home sites

Inspecting a mobile home begins with inspecting its site. Successful mobile home installations always begin with good site preparation and selection. Considerable planning for the installation for a mobile home as once they have been placed, they are seldom relocated.

Making sure the ground is stable will maintain the investment in the home. Since moisture is one of the largest enemies of any home, the understructure of mobile homes should be nice and dry. When moisture is present under a mobile home, a whole host of problems are likely to occur. All soil foundations must be properly graded.

Mobile home installation practices

Prior to installation all vegetation and organic material should be removed below where the home is to be located. Newer installations require that the pad be filled with gravel or a similar inorganic material above the surrounding finished grade. The slope of the grade should peak at the center of the mobile and slope to the outside of the home. A minimum slope of 2% is generally accepted. Sloping will prevent damaging water accumulation from under the structure.

Placing a plastic ground cover over the pad will assist in preventing moisture intrusion into the structure. The ground cover should extend at least 6 inches past the exterior perimeter of the home and be weighted down. Plastic ground covers help eliminate soil gas concerns.

If the home is to sit on a perimeter foundation wall, the foundation should conform to building code. When the home is supported by its longitudinal support on piers, it should be installed according to the manufacturer’s instructions and by observing specific anchorage and pier system arrangements governed by the local authority.

Clearances are important for access and ventilation. Usually the minimum acceptable clearance under the home is 24”. In the case of a sloped pad, minimum clearance between the bottom of the structure and grade level should be at least a 12”.

Where skirting is used, it should be designed to accommodate frost movement, be corrosion resistant or pressure treated, and its exterior finish be weather resistant. Make sure ventilation is installed in the skirting and that it appropriate access panels especially at sewer, water and power connections.

Quite often I see that the installation of an older mobile home doesn’t observe many of today’s mandated safe practices. Efforts to make existing homes conform to new standards will help safeguard the investment in the home.

The installation of the utility services of a mobile home is an important element. Make sure that requirements and regulations for utility hook-ups are met. The installation of the home’s ventilation systems is critical to the performance of the home. Appliances or clothes dryers should not be vented into the crawl space.

Mobile home inspections – electrical system

Mobile home inspections should prioritize safety concerns, starting with the electrical system. Used mobile homes may be offered for sale in British Columbia provided that they have a valid CSA approval mark and that the original wiring has not been altered without a permit. In the event the electrical wiring system has been altered without a permit, or there is no record of valid CSA approval, the mobile home must be re-inspected to satisfy the requirements of the BC Safety Authority and a new approval label applied to the home. Owners of mobile homes can certify their electrical systems at any time regardless of their CSA status.

If you need to certify using the BC Safety Authority process you will have to engage a licensed electrician to inspect and approve the entire electrical system. All of the receptacles and branch wiring circuits must be tested and properly bonded to ground for safety. If they aren’t, they must be otherwise protected to meet requirements for the safety of occupants. Any owner-modified and otherwise unsafe wiring must be brought up to current standards in order to gain certification.

Mobile home owners should observe the use of properly rated switches, bulbs and other electrical system components in their homes. Not using recommended or approved electrical components can result in safety hazards. Overloading electrical circuits, unsuitable convenience wiring or inadequate extension cords can lead to potential fires.

Speaking of fires, smoke and carbon monoxide alarms are critical for safety. The best exit is a fast exit. Make sure your alarms are in top notch working order. Remember, most alarms are good for up to 10 years, after that, they wear out and must be replaced.

Inspecting mobile home heating and cooling systems

The shear design nature of mobile homes results in maximizing the potential of their footprint. Mobile homes are designed to be self-contained and their heating and cooling systems are paired with their size. Mobile home furnaces are often installed in confined spaces and may result in contact with flammable materials. Special consideration must be made for clearances and an inspection should seek indications of exterior furnace failures. Clearances around interior vents should be observed for optimum efficiency and comfort.

Just like traditional homes, mobile homeowners can experience heating problems. Furnace heat exchangers should be evaluated by a HVAC technician, especially later in their service life. The potential for carbon monoxide leaks into the home should be eliminated. Regular filter maintenance is required for air filtration, to optimize the equipment’s efficiency and for safety. Of great importance is to evaluate the system’s flues and chimneys for proper operation and general condition.

Most mobile homes are cooled with wall mount or zone air conditioners. These units are regarded as personal appliances and are replaceable when the reach the end of their service lives. Mobile owners should pay specific attention to the condition of their cooling system. Older air conditioners that run constantly or have poor cooling performance are unsatisfactory. Observations of poor performance can be a result of a failing compressor or inadequate sizing. Remember that wall mount air conditioners require significant electrical power. Overloading a circuit can cause the breaker to trip or worse, a safety hazard.

More and more, mobile home owners are looking to ductless heat pumps for their indoor heating and cooling comfort. These units perform substantially like their traditional cousins and are ideally suited for mobile homes.

Mobile home inspection – plumbing and moisture

In the case of mobile homes in Canada, the Canadian Standards Association plays a large role in plumbing components. All plumbing system components should bear their approval. Where low quality tub and sink fixtures have been used, special attention should be used to look for cracks and leaks. Make sure that there are proper shutoffs have been installed at sinks and toilets.

Testing the waste distribution systems requires applying adequate flow at the fixtures for a significant period of time. Where water leaks, or where there is poor site drainage, water can mitigate from the understructure. Look for improperly installed moisture barriers and condensation drainage.

Mobile home inspection – structural and exterior issues

Most mobile homes have been engineered to be self-contained units that do not include to option of structural alterations or the installation of attachments without consequence. Avoid mounting of structural components to the exterior walls that can pull or push the structure. Additions like decks or stairs should be completely independent from the mobile home.

Insufficient sheathing beneath the siding and poorly installed skirting are problems to look for. Any penetration, whether it be through the roof, sides or underbelly of the home should be closely examined. Water leaks in the roof seams or covering, leaks at windows and doors can cause destructive deterioration and invite contamination and insect infestations. The under-wrap is particularly important for insulation purposes. It should be fitted properly and not hanging down.

Inspecting Mobile home additions

Renovations and additions to mobile homes should be conducted with proper permitting. Make sure that you contact your local building department prior to any additions or alterations to ensure you have the required permits.

Mobile homes are designed to be moved and as such don’t enjoy many of the permanent structural advantages that traditional homes have. Most mobile homes don’t have permanent stable foundations to tie into, nor do they accommodate or anticipate permanent additions in their design. Additional weight, pressure and support factors are not factored. 

Additions to mobile homes should be fashioned to be self-supporting and should have minimal contact. Sealing the gap between the units is acceptable. Factory built additions for mobile homes are available. They are constructed with portability in mind as well as standards for joining. Pre-constructed additions can be transported directly to the site for quick incorporation.

When adding an addition to a mobile home, make sure you consider the HVAC, plumbing and electrical needs of the new spacde.

Adding decks and porches to a mobile home

Decks are a great feature to enjoy the outdoors on. If you’re considering adding a deck to a mobile home approach it as a separate structure. This method will preserve the independent structural integrity of the mobile. The same strategy should be considered if you are considering adding a carport or steps.

Before you constructing any structural project, get in touch with your local building department for proper procedure and permitting.

Mobile home energy efficiency

There is a large energy efficiency line to be drawn between old and new mobile homes. This includes insulation and mechanical efficiencies.

Up until the mid-eighties most exterior walls of mobile homes were built form 2 x 4’s and insulated with R-12 fiberglass batt insulation. From the mid-eighties on, most exterior walls are 2 x 6 construction that have an R-20 value.

Ceiling insulation in older mobiles is minimal. Expect older homes to have a low R-value. Newer mobiles often have ceiling insulation of R-24 to R-34.

High air leakage in older mobile homes is common. After the early 70’s they are considerable tighter. Today’s mobile homes have fresh air venting incorporated into their design.

Forced air heating systems in older mobile homes delivered conditioned air to rooms but it wasn’t returned to the furnace by the same method. This resulted in uneven heating of the home especially when kitchen and bathroom exhaust fans were operated.

Draft proofing older mobile homes helps. Sealing exterior penetrations can help reduce air leakage significantly. Make sure that sufficient makeup ventilation is present to prevent back drafting of flue gases into the home when exhaust fans are operating.

On average, for older mobile homes, the largest improvements that can be made are:

Draftproofing 37%

Door and window replacement 12%

Exterior wall insulation 18%

Furnace upgrade 34%

Improving energy efficiency is best undertaken with a solid plan. I recommend engaging a professional energy advisor to assess the home and provide a step-by-step report.