A common method for providing a stable and level base for manufactured housing involves the use of concrete masonry units. These units, often arranged in a grid-like pattern, support the chassis of the home and distribute its weight evenly across the ground. This system elevates the structure, preventing direct contact with the earth and mitigating issues related to moisture and ground movement.
Proper support is essential for the longevity and structural integrity of a manufactured home. It prevents sagging floors, sticking doors, and other problems associated with uneven settling. Furthermore, this type of underpinning can provide a measure of protection against wind damage and may be a requirement for meeting local building codes or securing financing. Historically, alternative materials such as wood were used, but masonry units offer superior durability and resistance to decay.
The following sections will delve into the specific materials, installation techniques, inspection guidelines, and maintenance procedures related to this critical aspect of manufactured home construction. These elements are vital for ensuring a safe, stable, and code-compliant dwelling.
1. Material Durability
The selection of durable materials is fundamentally linked to the long-term performance of a manufactured home’s concrete masonry unit underpinning. The inherent properties of the materials used directly influence the foundation’s capacity to withstand environmental stressors and structural loads. Compromised material integrity can lead to settling, instability, and ultimately, significant structural damage to the home.
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Compressive Strength
Compressive strength, measured in pounds per square inch (psi), quantifies a block’s ability to resist crushing under load. Higher compressive strength is essential for supporting the weight of the home and mitigating the effects of ground movement or shifting. Inadequate compressive strength leads to cracking and crumbling, compromising the foundation’s ability to evenly distribute the load. The American Society for Testing and Materials (ASTM) standards provide guidelines for minimum compressive strength requirements for concrete masonry units used in foundation applications.
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Resistance to Moisture Intrusion
Concrete is porous, and prolonged exposure to moisture can lead to deterioration and weakening of the material. Freeze-thaw cycles, prevalent in colder climates, exacerbate this process. Water that penetrates the block expands upon freezing, causing internal stresses that can lead to cracking and spalling. Proper sealing and drainage around the foundation are critical for minimizing moisture intrusion and extending the lifespan of the masonry units. Hydrophobic admixtures can be added to the concrete mix to reduce water absorption.
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Chemical Resistance
Soil chemistry varies significantly, and some soils contain sulfates and other chemicals that can react with concrete, causing it to degrade over time. This chemical attack, known as sulfate attack, results in expansion and cracking of the concrete. Using sulfate-resistant concrete (Type II or Type V cement) is essential in areas with high sulfate concentrations in the soil. A soil test is recommended to determine the chemical composition of the soil surrounding the home.
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Dimensional Stability
Changes in temperature and humidity can cause concrete to expand and contract. While these dimensional changes are typically small, they can contribute to stress and cracking over time, especially in long, uninterrupted foundation walls. Properly spaced expansion joints allow for these movements, minimizing stress and preventing the formation of cracks. Reinforcement with steel rebar can also improve the dimensional stability of the foundation.
The interplay of these factors determines the overall durability and performance of the concrete masonry unit underpinning. Careful consideration of material selection, coupled with proper installation and maintenance, is crucial for ensuring the long-term stability and safety of the manufactured home. Failure to address these issues can result in costly repairs and a potentially unsafe living environment.
Frequently Asked Questions
This section addresses common inquiries regarding the use of concrete masonry units to support manufactured homes, providing clarification and essential information for homeowners and those involved in the installation or maintenance of these systems.
Question 1: What constitutes an acceptable concrete masonry unit for manufactured home support?
Acceptable units must meet or exceed the minimum compressive strength requirements as defined by applicable building codes and industry standards, such as those established by ASTM. They must be free from cracks, chips, or other defects that could compromise their structural integrity. Furthermore, consideration should be given to local environmental factors, such as soil composition and freeze-thaw cycles, when selecting appropriate materials.
Question 2: How frequently should a manufactured home’s underpinning be inspected?
Visual inspections should be conducted at least annually, with more thorough evaluations performed every three to five years, or after significant weather events such as floods or severe storms. Inspections should focus on identifying any signs of cracking, settling, displacement, or deterioration of the masonry units, as well as checking the condition of the mortar joints and any supplemental support structures.
Question 3: What are the primary indicators of a failing or inadequate support system?
Key indicators include uneven floors, doors or windows that are difficult to open or close, visible cracks in interior walls, sagging of the home’s chassis, and the presence of gaps between the home and the underpinning. Any of these signs suggest a potential structural issue requiring immediate attention and professional evaluation.
Question 4: Is professional installation of manufactured home underpinning necessary?
While some homeowners may attempt DIY installations, professional installation is strongly recommended. Trained professionals possess the knowledge and expertise to ensure proper leveling, spacing, and securing of the units, as well as adherence to local building codes and regulations. Incorrect installation can lead to structural problems, safety hazards, and potential legal liabilities.
Question 5: Can alternative materials be used in place of concrete masonry units for manufactured home support?
Alternative materials, such as treated wood or metal piers, may be permitted in some jurisdictions, but their suitability depends on local building codes, soil conditions, and the specific requirements of the manufactured home. Concrete masonry units remain a widely accepted and reliable option due to their durability, stability, and resistance to environmental factors.
Question 6: What maintenance procedures are essential for preserving the integrity of a concrete masonry unit foundation?
Essential maintenance includes ensuring proper drainage around the foundation, sealing cracks or deteriorated mortar joints promptly, and preventing the accumulation of debris or vegetation near the base of the home. Addressing minor issues proactively can prevent more significant and costly problems in the future.
Proper installation, regular inspection, and diligent maintenance are vital for ensuring the longevity and stability of a manufactured home’s support system. Consulting with qualified professionals and adhering to established guidelines are essential for safeguarding the investment and ensuring the safety of the occupants.
The following section will explore the legal and regulatory considerations surrounding manufactured home foundation systems.
Essential Tips for Manufactured Home Underpinning with Concrete Masonry Units
The integrity of a manufactured home’s foundation is paramount for safety and longevity. The following guidelines address critical aspects of installation and maintenance when utilizing concrete masonry units for underpinning.
Tip 1: Prioritize Site Preparation. Prior to installation, ensure the ground is properly graded and compacted. Uneven or unstable soil can lead to settling and structural issues. Remove all organic matter and debris, and consider a geotextile fabric to prevent weed growth and soil erosion.
Tip 2: Adhere to Code Requirements. Local building codes dictate specific requirements for the spacing, dimensions, and materials used in manufactured home foundations. Obtain the necessary permits and consult with local authorities to ensure compliance. Failure to adhere to these regulations can result in fines or mandatory remediation.
Tip 3: Use High-Quality Materials. Opt for concrete masonry units that meet or exceed industry standards for compressive strength and durability. Consider soil conditions and climate when selecting materials. In areas with high sulfate content, sulfate-resistant concrete is essential.
Tip 4: Ensure Proper Drainage. Implement a drainage system to divert water away from the foundation. Standing water can weaken the supporting structure and contribute to moisture problems within the home. Install gutters and downspouts, and ensure the surrounding ground slopes away from the foundation.
Tip 5: Maintain Consistent Spacing. Proper spacing of the concrete masonry units is crucial for even weight distribution. Follow the manufacturer’s recommendations and local code requirements for the distance between supports. Inadequate spacing can lead to sagging floors and structural stress.
Tip 6: Implement Adequate Ventilation. Provide adequate ventilation beneath the manufactured home to prevent moisture buildup. Install vents in the skirting or foundation walls to allow for airflow. Poor ventilation can contribute to mold growth, wood rot, and other moisture-related problems.
Tip 7: Regularly Inspect and Maintain. Conduct routine inspections of the foundation to identify any signs of cracking, settling, or deterioration. Address any issues promptly to prevent them from escalating. Seal cracks and repair damaged mortar joints to maintain the integrity of the underpinning.
Adherence to these guidelines minimizes the risk of structural problems and ensures the long-term stability of a manufactured home. Regular maintenance and proactive problem-solving are essential for preserving the investment and safeguarding the residents.
The next segment will cover regulatory requirements of this type of foundation.
Mobile Home Block Foundation
The preceding discussion has highlighted the critical factors associated with the use of concrete masonry units in supporting manufactured homes. Proper material selection, meticulous installation techniques, diligent maintenance practices, and adherence to regulatory guidelines are paramount for ensuring the structural integrity and longevity of the dwelling. The long-term stability of a manufactured home is directly contingent upon the robustness and effectiveness of its foundation system.
Therefore, prioritizing professional expertise and comprehensive understanding of relevant codes is essential. Neglecting these aspects can lead to significant structural problems, safety hazards, and financial burdens. A well-maintained support system is not merely a structural component but an investment in the enduring safety and value of the manufactured home. Owners are encouraged to seek professional advice and rigorously implement preventative measures to safeguard their property and ensure the well-being of its occupants.
