Modular Home Foundations
Modular Home Foundations
Modular Home Foundation Types
Modular Home Conditioned and Non-Conditioned Foundations
Another question to answer is if the foundation space will be conditioned or non conditioned space. Depending on your use of the foundation and the topography of your land will determine if the foundation for your modular home should be conditioned or non conditioned space.
Foundation Materials for Modular Homes
Deciding on the material used to construct your modular home's foundation will depend on your building budget and the use of the foundation space. The primary materials used for a modular home foundation include poured cement; cement blocks; ICFs (insulated concrete forms); prefab cement walls (Superior Walls) or wood panels.
Modular Home Foundations and Crawl Spaces
Full Foundation Spaces - A full foundation space for your modular gives your a basement under your entire home. A basement can then be used for storage or living space. If you are going to use the basement strictly as a storage space you will not be required to install egress-able windows or doors. If you are planning to finish the space in the future it is wise to install agreeable windows and doors to meet state and local building codes in the future. The next decision to make is if your modular homes foundation basement is going to be conditioned or non-conditioned space.
Crawl Space - a crawl space is just that - an area where you can crawl under the home. Crawl space might be used to save a few bucks, but in the end a crawl space is a poor decision. Another reason a crawl space might be used is to contend with high ground water levels. Either way the crawl space is worthless space. If you have high ground water levels, you should consider bring in fill or building a raised modular home unit where half of the foundation wall is framed so the foundation space can be used in the future.
Conditioned vs. Non-Conditioned Foundations
Conditioned Modular Home Basements - Conditioned basement space for a modular home means the foundation walls and floors will be part of the thermal envelope of the home. Conditioned basements require the walls and floor of the foundation to be insulated. The walls can be insulated with spray foam, fiberglass or rigid insulation board. The concrete floor of a modular home basement should be insulated with four inches of rigid insulation board. The side walls should have an R-Value of thirty and the floors should have a minimum R-Value of 10. A conditioned foundation space will need to be "connected" to the space above if its a crawl space.
Non Conditioned Modular Home Basements - Non-Conditioned basements mean the basement is treated as though it is outside the thermal envelope. The ceiling of the basement is the thermal envelope and the door to the basement will be treated as an exterior door. This is the cheapest type of basement because only the ceiling and require air sealing and insulation. The R-Value of a modular home basement should be an R-30 and the door should be an ENERGY STARŪ rated exterior door.
Modular Home Foundation Materials
Poured Cement Foundation Walls for Modular Home Foundations
Cement Block Walls for Modular Home Foundations
Insulated Concrete Forms for Modular Home Foundations
Prefab Cement Walls or Superior Walls for Modular Home Foundations
Wood Modular Home Foundations
Slabs and Flatwork
The most important site constructed component for a modular home is the foundation. The foundation must be square, plumb and built to the correct dimensions
Types of Foundation for Modular Homes
Modular homes require a foundation and can not be built slab on grade. Modular homes require space under the home for electrical, HVAC and plumbing connections. The two types of Foundation for modular homes include full foundations and crawl spaces. Prefab home foundation can be conditioned or non conditioned space. Depending on the topography of your building lot, you could take advantage of a walk out basement.
Modular Home Foundation Insulation
Depending on if your foundation for your prefab home is going to be conditioned or non conditioned will determine if the walls, ceilings and or floors will be insulated. In the past, foundation insulation was over looked leading to cold and uncomfortable floors. In addition to insulating a modular home foundation it is important to air seal the foundation space to minimize prefab home air leakage and drafts in the foundation or basement.
Foundation Materials for Modular Homes
Modular Home foundations can be constructed on site or manufactured in a factory and installed on site, much like a modular home. Foundation materials for modular homes include cement and wood. Stone foundation are not conducive to modular home or site built construction due to the irregularities of stone as a building materials. It is important for the your prefab home foundation to be square, plumb and correctly sized.
Foundation Drainage and Damp Proofing
The key to a dry basement for your new modular homes is to properly drain the area around the foundation of the home. This includes correctly directing roof run off water away from the foundation, foundation drains and damp proofing the exterior walls of the foundation. In addition to stopping moisture from getting into your new prefab home foundation, installing drains and sump pumps is a method to remove any moisture that does penetrate the foundation space.
Modular Home Foundation Moisture Control
Modular Home Finished Foundation Spaces
One of the most economical space to convert to living space is the basement of a home. If the building site is sloped to accomodate a walk out basement it is wise to take advantage of your modular homes foundation space as living space. If the prefab homes building site is not sloped, you will be required to install egress systems so the foundation will comply with today's building codes.
Finished Basements for Modular Homes
Foundation Flatwork for Modular Homes
Today is common for all homes to have a cement poured in the prefab homes foundation space. Poured cement acts as a moisture barrier to stop ground water from entering the new modular homes foundation space. In addition to installing cement it is important to install a vapor barrier and insulation under the foundation slab.
Modular Home Foundation Slabs and Flatwork
Check List For A Modular Home Foundation
A good builder will use a check list before, during and after the construction of a modular home foundation. The check list will make sure the foundation is: square and plumb; mechancicals are correctly located; drainage systems are properly located and etc. Checklists will help minimize the cost of building by eliminating the potential of forgotten planning elements and expensive retrofits to your prefab homes foundation.
Modular Home Foundation Check List