Learning how to build a luxury epoxy flooring is not as daunting as one would expect, well, for detached structures at least. Homeowners who build their own garage can save thousands over hiring a builder who, in many cases, will subcontract to the same construction crews that you can hire. Or if feeling adventurous, or just downright thrifty, one can invite friends over for a few beers over the weekend and put them to work.
There are many items to consider while in the early planning stage such as:
Garage size: One car, two car, or even a three car garages can be designed with various sizes, but the lot and homeowner’s budget are generally the limiting factors. Local building codes vary, but typically a structure must not encroach within eight feet of property lines in rural areas and from zero to four feet in city limits. Detached garages must also be set back from other buildings by a minimum of eight feet, but this must be confirmed with local building offices as bodes vary. One important consideration is roof overhang. Eave and gable end overhangs are typically 12″ – 24″ (although less than 12″ is common in windy areas) and must be considered when determining building size and placement.
One method of determining the perfect size is to add 12′ to 15′ of width for each vehicle. If planning to use the interior walls on the sides for storage this will require another two feet of width per side. The length should be a minimum of 22′ and add four to ten feet for a work bench and storage. A two car garage could be calculated as 2 x 12′ +4′ for storage along each wall = 28′ x 22′ long without a work bench. Common sizes include:
1. One car: Common garage sizes include 12′ x 24′, 14′ x 24′, and 16′ x 24′. A length of twenty four feet is pretty much the minimum if you have a full size truck and even with a small or mid-size car there will be little wiggle room at twenty or twenty two feet.
2. Two car: The most common garage size in many states and provinces is 24′ x 24′ because many building codes required an engineered drawing and two inspections by a structural engineer for concrete floating slabs (monolithic) larger than this size. If space is scarce and the two cars are small to mid-size a 20′ wide may adequate, but certainly not comfortable.
3. Three car: There are many three car garage sizes due to more room for numerous designs and homeowners often have larger budgets when considering these larger construction projects. Common sizes are 36′ – 42′ wide by 26′ – 30′ long.
Foundation: floating slab (monolithic) and slab with frostwall are the two most common foundation options. The floating slab is less expensive and easier to build, but often require an engineered drawing and two inspections for larger concrete slabs (i.e. 24′ x 24′). In cold weather climates many contractors install 2.5″ foundation foam under the concrete to reduce heaving during freeze/thaw events. Engineered floating slabs in cold climates usually require this with an addition two feet extending out around the perimeter of the slab.
Adding 6′ x 6′ #10 wire mesh to the slab is an inexpensive method of increasing the floor strength and reducing cracking of the concrete. Most contractors install floating slabs with a thickened concrete perimeter 12″ – 16″ thick around the outer 16″ – 24″ of the perimeter. Adding two rows of #4 rebar will increase the edges. Concrete strength should be a minimum of 3,000psi and many contractors use 4,000 and 4,500 psi as the additional cost is minimal. Another consideration is ordering concrete with fibermesh, and macro-synthetic fiber used for secondary reinforcement of concrete. Local concrete suppliers can provide costs for adding this to concrete. Slab thickness is dependent on the concrete strength and reinforcement designs, however a good rule of thumb is to pour a 4″ or thicker slab.
Frostwall minimum depth is determined by local building codes and is typically 48″ in cold climates and 36″ in more moderate areas. Once the trench is excavated a footing approximately 12″ wide by 8″ thick is formed and poured and a keyway is etched the length of the footing to prevent movement of the concrete wall. The frostwall is formed and poured on the on the footing and anchor bolts are installed in the to attach the walls to the foundation. The concrete slab is then poured to designed thickness. Obviously this foundation system requires more time and expense.
