If you are buying or selling a manufactured home in California, sooner or later someone may ask whether the property has a "433A" or, less directly, whether the home is on a “permanent foundation.” Unfortunately, the term "permanent foundation" is often used loosely and can create confusion. How a manufactured home is physically installed and anchored to its foundation is one subject. Whether it has been installed and documented under the 433A process—and therefore treated as a fixture or improvement to the real property—is another completely separate subject.

What Is a 433A?

Form HCD 433A, issued by the California Department of Housing and Community Development (HCD), is formally called the Notice of Manufactured Home, Mobilehome, or Commercial Modular Installation on a Foundation System. It is used when a manufactured home is installed on an approved foundation system as a fixture or improvement to the underlying real property under California Health and Safety Code §18551(a).

The installation is permitted and inspected by the appropriate enforcement agency. After approval and issuance of a Certificate of Occupancy, the 433A is recorded with the county recorder. The recorded document provides legal notice that the manufactured home has become a fixture or improvement to the real property, rather than remaining separately titled personal property. HCD's title record is then changed accordingly.

These distinctions can be important to lenders, title companies, appraisers, buyers, sellers, and taxing authorities.

Does Every California Manufactured Home Need a 433A?

No. California law allows manufactured homes to exist as personal property as well as real property. Many manufactured homes have been legally installed for decades while remaining separately titled through HCD.

The absence of a recorded 433A does not, by itself, mean that the home was improperly installed or that there is something physically wrong with its foundation. A 433A is used when the manufactured home is installed on an approved foundation system as a fixture or improvement to the underlying real property under California Health and Safety Code §18551(a).

California law even recognizes that a manufactured home can be installed on a foundation system while remaining chattel, or personal property. That is an important distinction: being attached to a foundation and being legally part of the real estate are not the same thing.

The Confusing Term: “Permanent Foundation”

Much of the confusion comes from the phrase "permanent foundation." In ordinary construction terminology, most people hear “permanent foundation” and imagine a traditional poured-concrete or masonry perimeter foundation similar to the foundation beneath a site-built house. In manufactured-housing, real-estate, and lending discussions, however, the term is also commonly used to describe the home's legal status.

California HCD itself uses “permanent foundation” in some contexts to describe a manufactured home installed on a foundation system as a fixture or improvement to the underlying real property, inspected and approved by the building official, with the 433A recorded. This is where much of the confusion originates. In construction and inspection terminology, “permanent foundation” may describe a physical foundation configuration. In California real-estate and lending terminology, the same words may instead refer to the home's legal status.

Standard Set Versus Permanent Set

For inspection purposes, manufactured-home installations are commonly described nationally using two broad physical configuration types:

1. Standard Set. A Standard Set manufactured home is typically supported beneath its structural frame by piers. These may include concrete masonry piers, manufactured metal supports, or other approved components. Footings or pads transfer the loads to the soil. The manufactured home also requires an anchoring or bracing system to resist forces such as wind and earthquakes.

Because the piers and underside of the manufactured home would otherwise remain exposed, a nonstructural enclosure or skirting is commonly installed around the perimeter. Skirting may be constructed from numerous materials, including manufactured panels, metal, masonry, wood products, or other materials.

The important point is that the skirting normally is not the foundation. The manufactured home's structural loads are generally being carried by the piers and supporting system behind it.

2. Permanent Set. With what inspectors commonly describe as a Permanent Set, the manufactured home is installed over a foundation more closely resembling that of a conventional site-built house. There may be a poured-concrete or reinforced-masonry perimeter foundation supported by concrete footings, creating a conventional crawlspace or sometimes a basement.

Interior supports or piers are still commonly necessary because manufactured homes are generally designed to carry substantial loads through their steel chassis or other designated structural support locations. The home is then structurally connected or anchored to the foundation system. Because the perimeter foundation itself encloses the crawlspace, separate decorative skirting is generally unnecessary.

What About the Hitch, Axles and Wheels?

Another common misconception is that a manufactured home becomes real estate once the wheels, axles, or towing equipment have been removed. It isn't that simple.

Manufactured homes are designed and built for transportation to their installation site. Removing transportation components may be part of an installation, but the presence or absence of those components does not, by itself, establish whether the home is legally personal property or real estate.

Likewise, seeing an old hitch beneath a manufactured home does not establish that there is no 433A. The presence or absence of transportation components does not determine the home's legal property status; that status must be established from the appropriate records.

Can a Home Inspector Determine Whether a Manufactured Home Has a 433A?

No. A home inspector can inspect the visible physical condition of the manufactured home's foundation and support system. Depending upon accessibility and the scope of the inspection, that can include observations involving:

• piers and supports;
• foundation walls and footings;
• anchoring or bracing components;
• visible deterioration or damage;
• improper or displaced supports;
• crawlspace conditions; and
• other visible structural concerns.

What a visual home inspection generally cannot establish is whether the installation was properly engineered, whether every component conforms to the original approved foundation design, whether all required permits received final approval, or whether a 433A was recorded. Those are documentation questions.

A manufactured home's legal status should normally be confirmed through sources such as the county recorder, HCD records, title company, lender, and applicable local building department.

Why Does a 433A Matter When Buying a Manufactured Home?

The issue frequently arises because of financing. A lender may require documentation establishing that a manufactured home is legally attached to the underlying real property before it will make a particular type of real-estate loan. That is why buyers often first hear about a “433A” from a lender, appraiser, real-estate agent, or title company rather than from a home inspector.

A lender may require a recorded 433A before financing a manufactured home as real estate. That does not mean every manufactured home in California is required to have one. Many manufactured homes remain legally titled as personal property.

For a buyer, the practical question is whether the home's current title and foundation status satisfy the requirements of the proposed loan and transaction.

Three Important Questions That Should Be Kept Separate

When evaluating a California manufactured home, it helps to ask three different questions:

1. Is the foundation and support system physically performing adequately? That is primarily an inspection and structural-condition question.
2. Was the manufactured home installed using an approved foundation system and were the appropriate permits and approvals obtained? That is primarily a permitting and engineering documentation question.
3. Has a 433A been recorded so that the manufactured home is legally a fixture or improvement to the underlying real estate? That is primarily a title and public-records question.

The answers to those questions may be related, but they are not interchangeable.

The Bottom Line

​Don’t be confused by the terminology. The key points are:

• A California manufactured home does not automatically require a 433A.
• The 433A, if filed with the county recorder, documents a specific legal process in which a manufactured home installed on an approved foundation system becomes a fixture or improvement to the underlying real property.
• It should not be assumed that “permanent foundation” means the manufactured home must be sitting on a traditional concrete perimeter foundation.
• You generally cannot determine whether a manufactured home has a 433A simply by looking underneath it.
• The physical foundation should be evaluated for its visible condition, while legal status, permitting, title, and financing requirements should be verified through the appropriate records and professionals.

Understanding these differences can eliminate a great deal of unnecessary confusion when buying or selling a manufactured home in California.

The foundation is the backbone of your home—literally. It determines how your home handles moisture, shifting soil, and even energy efficiency. Two of the most common foundation types are slab and crawlspace. Each comes with its own benefits, drawbacks, and maintenance requirements. Understanding the differences can save you thousands in repairs and help you choose the right home for your needs.

A slab foundation is a single layer of poured concrete, usually 4–6 inches thick, that rests directly on the ground. Plumbing lines and sometimes HVAC ducts are embedded within or beneath the slab.

✅ Pros of Slab Foundations:

• Lower cost: Usually cheaper to build than crawl spaces.
• Fewer pest problems: No open space for rodents or termites to invade.
• Low maintenance: No crawl space to inspect or ventilate.
• Better energy efficiency: No cold air circulating under the home.

❌ Cons of Slab Foundations:

• Plumbing repairs are sometimes harder: Drainage pipes are embedded in or under the slab, making leaks expensive to fix.
• Cracking risks: Soil movement or poor drainage can cause cracks.
• Limited access: No underfloor storage or easy access to wiring/ducts.

A crawl space foundation elevates the home 18–36 inches above the ground, leaving a small space between the home and the soil. Utilities like plumbing and ductwork often run through this space.
 
✅ Pros of Crawl Spaces:

• Easy access for repairs: Plumbing and wiring are accessible.
• Better for sloped lots: Crawl spaces adapt to uneven terrain.
• Elevated protection: Keeps home above potential flooding (to an extent).

 
❌ Cons of Crawl Spaces:

• Moisture problems: Without proper ventilation or encapsulation, mold and rot can develop.
• Pest risks: Rodents, termites, and other pests love dark, damp spaces.
• Higher energy costs: Exposed underfloor can lose heat unless insulated properly.

Which is Better?
There’s no one-size-fits-all answer. If low maintenance is your priority, a slab might be best. If you value accessibility for repairs and plan to run utilities under your home, a crawl space may make more sense. Just remember: proper drainage and ventilation are key to either option’s long-term performance.
 

Water is one of the most destructive forces a home can face, particularly when it comes to its foundation. Poor drainage can lead to soil erosion, foundation cracks, basement flooding, and even structural instability. Fortunately, by taking proactive steps such as grading the landscape correctly, maintaining gutters and downspouts, and installing proper drainage solutions, homeowners can protect their investment and avoid costly repairs.

Grading Around the House
The slope of the ground around your home—also known as grading—is a crucial factor in directing water away from the foundation. Ideally, the soil should slope away from the house at a minimum of 6 inches over the first 10 feet. If the ground is flat or slopes toward the foundation, water can accumulate and seep into basements or crawl spaces, leading to moisture issues and potential damage.

If your yard is not properly graded, you may need to add soil around the foundation to create a proper slope. This should be done using compacted fill dirt rather than mulch or loose soil, which can wash away easily. In cases where regrading is not feasible, alternative drainage solutions such as swales or French drains may be necessary.

Gutters and Downspouts: First Line of Defense
Gutters and downspouts play a crucial role in directing rainwater away from the foundation. When they are clogged, damaged, or improperly installed, water can overflow and pool around the home, leading to moisture issues and potential structural damage.

• Clean gutters at least twice a year to remove leaves and debris.
• Check for leaks, sagging, or improper installation.
• Ensure gutters are properly pitched so water flows toward the downspouts.

Downspouts should discharge water at least 5 feet away from the foundation. If they are too short, water can pool near the base of the house. Adding downspout extensions or splash blocks can help direct runoff away effectively.

Drainage Solutions to Prevent Water Damage
Even with proper grading and gutter maintenance, some properties may still experience drainage issues due to soil type, landscaping, or other factors. In such cases, additional drainage solutions may be required.

• Swales—A swale is a shallow, sloped channel designed to guide excess water away from the home. It can be lined with grass, gravel, or stone to slow down water flow and prevent erosion.
• French Drains—A French drain consists of a perforated pipe buried in a trench filled with gravel. It collects and redirects water away from the home, making it an effective solution for properties with persistent drainage problems.
• Sump Pumps and Drain Tiles—For homes with basements or crawl spaces prone to water intrusion, installing a sump pump system or exterior drain tiles can provide extra protection by actively removing water from around the foundation.

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Conclusion
Protecting your home’s foundation from water damage starts with proper grading, gutter maintenance, and effective drainage solutions. Whether it is regrading the soil, extending downspouts, installing swales, or adding a French drain, these measures help keep your foundation dry and stable. By taking proactive steps now, homeowners can avoid costly repairs and ensure their homes remain structurally sound for years to come.

​Concrete can crack for a myriad of reasons, often due to the complex interplay of several factors. Here are some common causes:

• Shrinkage: As concrete cures and dries, it shrinks. If the shrinkage is restrained, tensile stresses develop, which can lead to cracking. This is often referred to as drying shrinkage. 
• Drying Too Fast: If concrete dries too quickly, it can lead to increased shrinkage and cracking. Rapid drying can be caused by high temperatures, low humidity, wind, or inadequate curing practices. Proper curing is essential to control the rate of moisture loss and ensure the development of concrete strength.
• Lack of Expansion Joints: Expansion joints are crucial in allowing the concrete to expand and contract with temperature changes. Without them, the concrete is more likely to crack due to thermal stresses. If joints are not properly placed or designed, or if they are not filled correctly, cracks can form along these weak points.
• Lack of Quality Control: Improper mixing, placing, or curing of concrete can lead to defects and increased susceptibility to cracking. Too much water in the concrete mix can weaken the concrete, making it more susceptible to cracking. Certain chemical reactions within concrete, such as alkali-silica reaction (ASR), can cause expansion and cracking over time.
• Thermal Stress: Temperature changes cause concrete to expand and contract. Rapid temperature fluctuations can induce thermal stresses, leading to cracks.
• Freeze-Thaw Cycles: In colder climates, water can seep into concrete, freeze, and expand. This cycle of freezing and thawing can cause cracking.
• Load Stress: Concrete is strong in compression but weak in tension. Excessive loads, especially those causing bending or stretching, can lead to cracking.
• ​Subgrade Settlement: If the ground beneath the concrete settles unevenly, the unsupported concrete can crack due to the stress.
• Corrosion of Reinforcement (rebar): In reinforced concrete, if the steel reinforcement corrodes, it expands and causes the surrounding concrete to crack.

Proper design, material selection, and construction practices are key to minimizing the risk of cracking. Understanding the specific cause of cracking in any given situation often requires a detailed analysis of the construction process, materials used, and environmental conditions.

Manufactured homes provide a cost-effective and efficient housing solution for many. One common issue faced by owners of these homes is the appearance of cracks along the marriage line—the joint where different sections of the home are joined together. Hairline cracks are somewhat normal and nothing to be too concerned about. However, more significant cracks are generally caused by movement within the foundation system that need to be addressed. Understanding why these cracks form and how to repair them can help you maintain the structural integrity and aesthetic appeal of your home. In this article, we will explore the causes of these cracks and provide steps to fix them.

What is the Marriage Line?
The marriage line is the seam where two sections of a manufactured home are joined. This critical area is secured with bolts, screws, and other fasteners to help ensure structural stability. However, because it is a junction point, it is particularly vulnerable to stress and movement.

Why do Cracks Form?
Cracks along the marriage line in manufactured homes are primarily caused by foundation movement due to excess moisture in the soil, but can also be caused by thermal stresses and seismic movement. Moisture-related movement can occur due to several reasons:

• Drainage Issues: Water in the soil and pooling around the foundation can lead to soil erosion or swelling, both of which can destabilize the foundation. Some typical root causes of moisture issues are:
  • Lack of rain gutters
  • Downspouts that discharge next to the foundation
  • Homes installed on a slope with inadequate surface and sub-surface drainage (e.g. swales, French drains, etc.) around the home
  • Lack of ventilation in the crawlspace
• Soil Conditions: Expansive soils that swell with moisture and shrink when dry can cause significant foundation movement, leading to stress on the marriage line.
• Seasonal Changes: Temperature fluctuations (e.g. freeze and thaw) can cause the soil to expand and contract, leading to foundation shifts.
• Improper Foundation: An inadequately designed or installed foundation can shift, causing the sections of the home to move and develop cracks. An occasional problem are single-stack piers instead of double-stacked piers installation along the marriage line—check your home manufacturer’s installation and setup instructions.

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Fixing Cracks in the Marriage Line
Before addressing the cracks, inspect the foundation of your home or have it professionally inspected. Look for signs of movement such as: uneven floors; deteriorated wood pads and shims; tilted, sunken, or fallen-down piers; and gaps between piers and support beams. Also, look for signs of excess moisture such as: pools of water, evidence of past pooling, efflorescence (the white chalky residue left when water evaporates), wood rot, and soil erosion.

Step 1: Address the Root Cause(s) of the Problem

The first step is to address the root causes of the problem unique to your home, which are most often related to moisture. Common solutions include:

• Fix any plumbing leaks
• Address any grading issues (surface water drainage flowing towards foundation) which might include installing swale(s) to divert surface water away from the foundation
• Installing rain gutters
• Installing downspout extenders and splash blocks to divert water away from the foundation
• Install French drains around the foundation to remove water from the soil
• Improving ventilation under the home
• Installing a vapor barrier (link)

Geotechnical engineering is the study of the behavior of soils under the influence of loading forces and soil-water interactions. If you live in an area with expansive soils, please consult with a geotechnical engineer who may recommend soil stabilization techniques, such as:

• Adding lime to the soil reduce the plasticity and swell potential
• Adding cement or fly ash to improve the soil strength and reduce expansiveness
• There are other chemical additives that can be used

Step 2: Fix Foundation Issues While Re-Leveling the Home

This step is best done by professionals, but it is possible to do as a DIY project if you have the right tools (hydraulic jack, laser-level, bubble level, tape measure, etc.) and mindset. Common remedies include:

• Re-constructing tilted and fallen-down piers
• Installing additional (new) piers as needed
• Replacing single-stack piers with double-stack piers along the marriage line(s)
• Replacing (rotted) wood pads with prefabricated (plastic) or concrete pads
• Adding and removing shims to achieve level

​Optional advanced measures:

• Pouring concrete footers
• Replacing standard (dry-stack concrete block) piers with adjustable metal piers

Step 3: Repair the Cracks

Clean the cracked areas to remove any dust, debris, or loose material. This ensures that the caulk and joint compound adhere properly.

For small cracks, use a flexible, paintable caulk to fill the gaps. Load the caulk into a caulking gun and carefully apply it along the crack. Smooth it out with a putty knife and allow it to dry according to the manufacturer’s instructions.

For larger cracks:

1. Apply a layer of joint compound over the crack using a putty knife.
2. While the compound is still wet, place drywall tape over the area and press it into the compound.
3. Apply another layer of joint compound over the tape, smoothing it out to blend with the surrounding wall. Allow this to dry completely.
4. Once the joint compound is dry, sand the area smoothly with a sanding block or sandpaper. This helps to blend the repaired area with the rest of the wall.

Prime the repaired area to prepare it for painting. Once the primer is dry, paint the area to match the rest of your wall. This will help make the repair virtually invisible.

Preventing Future Cracks
While it's impossible to eliminate the risk of cracks entirely, you can take steps to minimize them by:

1. Maintaining proper drainage around the home to prevent water pooling and soil erosion.
2. Periodically inspecting your foundation yourself or have your home inspected by a professional to catch and address potential foundation issues early.
3. Depending upon need, it is recommended that you re-level your home every few years, with a suggested maximum of five year intervals.

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Conclusion
Cracks along the marriage line of a manufactured home can be a distressing issue, but they are often manageable with the right approach. By understanding that these cracks are typically caused by foundation movement, and by following the steps outlined above, you can repair and help prevent future cracks, ensuring your home remains safe and comfortable. Regular maintenance and attention to your home’s foundation are key to preventing these issues from recurring. With proper care, your manufactured home can continue to provide a secure and appealing living space for years to come.

Hidden beneath our feet, crawlspaces play a crucial role in the structural integrity and health of our homes. These dark and often damp places can harbor moisture-related problems leading to potential health hazards and structural damage. Thankfully, vapor barriers made from polyethylene plastic sheeting are a relatively inexpensive method to help control moisture. In this article, we explore the significance of vapor barriers in helping to prevent water from the ground causing high humidity within the crawlspace and the rest of the home.

Understanding the Role of Ground Vapor Barriers
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Excluding the obvious sources of water vapor into the crawlspace such as interior water leaks and water intrusion from the exterior, the single largest source of humidity within a crawlspace is from the ground itself through water evaporation. Water from the exterior of the house will infiltrate to the interior ground surface of the crawlspace through simple capillary action where it then evaporates.

A vapor barrier is a thin, impermeable material typically made from polyethylene or similar plastics. When installed on the ground in a crawlspace it acts as a protective shield, preventing water vapor from the damp soil below from rising and infiltrating the crawlspace and living spaces above. This simple yet effective technique offers a multitude of benefits, ensuring a healthier and more comfortable home environment.

The Perils of High Humidity

High interior humidity levels can lead to a host of problems, some of which may not be immediately apparent:

1. Mold and Mildew Growth: Excessive moisture encourages the growth of mold and mildew, leading to unsightly stains, foul odors, and potential health issues for occupants.
2. Dust Mites and Allergens: Humid environments provide an ideal breeding ground for dust mites and allergens that can trigger allergic reactions and respiratory problems in sensitive individuals.
3. Reduced Comfort: High humidity levels make indoor spaces feel sticky and uncomfortable.
4. Structural Damage: Prolonged exposure to moisture can cause corrosion of metal in electrical, plumbing, and structural components and can rot wooden beams, floor joists, and other structural elements, compromising the overall integrity of the home.

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Mobile and manufactured homes often have unique challenges compared to traditional houses, including a higher susceptibility to moisture-related issues. Due to their mobility and often temporary installations, they are more prone to uneven ground, which can lead to poor drainage and increased moisture within the crawlspace.​

Benefits of Vapor Barriers

The benefits of installing vapor barriers in crawlspaces are significant:

• Mold and Mildew Prevention: High humidity levels and excess moisture create an ideal environment for mold and mildew growth, ultimately leading to corrosion of metals, wood rot, and damage to structural elements. By helping to maintain a dry environment, vapor barriers extend the life of your home's foundation and other systems.
• Improved Energy Efficiency: By keeping the crawlspace dry, the installed insulation's effectiveness remains intact, reducing the strain on HVAC systems and resulting in lower energy bills.
• Pest Mitigation: Vapor barriers on the ground can help to discourage and thwart infestation from subterranean termites, burrowing animals, and other unwanted critters.
• Radon Mitigation: Radon is present in our area, but not prevalent; click here for more information. Ground vapor barriers are a common mitigation measure against radon, should that be present, promoting a cleaner and safer living environment.

 
In the quest to protect our homes from moisture-related issues, the vapor barrier has emerged as an invaluable ally. From controlling moisture and preventing mold growth to enhancing energy efficiency and structural integrity, vapor barriers play a vital role in safeguarding our living spaces. Embracing this essential technology allows us to ensure the long-term safety, health, and comfort of our homes.