One of the most important decisions you make in building your log cabin is the foundation selection. According to The International Association of Certified Home Inspectors (InterACHI) the purpose of a foundation is to “transfer the load of a structure to the earth and resist loads imposed by the earth.” Several factors impact your foundation decision including climate, geography, water tables, topography, properties of the soil, local code requirements, personal preference and budget.
Regardless of the type of foundation, the majority of American log cabin foundations are built with some form of concrete, either poured, block or precast. Some types of foundations used for log cabin homes are slab, pier, crawlspace and basement. They all have advantages and disadvantages.
Concrete Slab Foundation
A flat concrete pad is installed and requires that the lot be graded prior to construction. Ungraded lots may experience drainage issues if water is not directed away from the log cabin walls. A vapor barrier between wet soil and concrete is recommended.
Advantages of Concrete Slab
- Requires less labor and excavation which means quicker completion and lower cost
- Prevents rodents from nesting under your log cabin
- Entrances to your log cabin will only be a step or two, which can be important if occupants have difficulty climbing stairs.
Disadvantages of Concrete Slab
- Limited access to any systems installed under floors such as plumbing or electrical
- Poor construction could lead to uneven flooring, drainage problems and moisture penetrating through cracks
- Unpredictable performance in areas of prolonged frost
A pier foundation can consist of concrete cylindrical columns (piers) placed in the ground to support the load of a log cabin while elevating it off the ground.
Advantages of Pier Foundations
- Allows access to electrical and plumbing systems
- Less expensive than crawl space
- Suitable for sloped lots
- Allows for thorough termite inspection
Disadvantages of Pier Foundations
- Without proper ventilation, moisture can build up leading to mold and rotting in wooden floors.
- Interior flooring can be squeaky and prone to vibration
- Rodents have easier access to your log cabin
Similar to pier foundations but crawl spaces have a perimeter wall. Crawl spaces should be at least three to four feet.
Advantages of Crawl Spaces
- Can accommodate HVAC and plumbing systems making them accessible for maintenance
- The perimeter wall can add curb appeal and be constructed out of material such as stone or brick.
Disadvantages of Crawl Spaces
- Potential problems with moisture are not as noticeable.
- Poorly installed or unsealed ducts can lead to unwanted materials (dust, moisture) circulating through your ventilation
Think of a basement as a combination of a slab foundation and crawl space. Basements are usually built on a concrete slab but are dug to at least eight feet deep.
Advantages of Basements
- Provide additional storage space
- Can be finished for extra living space without increasing log cabin’s footprint
- Basements provide a cooler space during warm weather
- Excellent location for mechanical equipment providing easy access for maintenance and repairs
Disadvantages of Basements
- Most expensive foundation to build due to excavation, material and labor costs
- Tend to be damp
- Not an option in areas with high water tables or unsettled soil
- Cave-like if without day light
The strength and stability of your log cabin rely on a firm foundation. Geography, climate and personal preference should guide your decision. Talk with a professional in your area to ensure that you are making the right choice as well as abiding by local code requirements.