Insulation is a critical component to building. There are so many
considerations as to HOW a garage, accessory structure or attached
garage is properly built. Despite the best of trade work, no line is
perfectly straight. No hole perfectly bored. There is an industry
standard that the State and Federal government prescribe for all
Having several interacting components such as HVAC, Electrical,
Mechanical and Plumbing work all running together in the walls and
ceilings of garages and additions require fire-hazard and insulation
evaluation. Wires have to have a grounding point and need special
insulation to properly conduct electricity. Electrical services require
holes and notches in and around lumber – studs and trusses. A
grounding rod is used in monopour foundations, or rebar in the footing
can be tied together with copper wire mesh to prevent imploding. HVAC
work requires areas to run ductwork and plumbing requires ample space
through the slab and floor joist systems. All of these holes and areas
have to be insulated to protect them from decay as well as the escape
and infiltration of air.
When attaching a new garage to your home, the foundation area and
adjoining walls have to be insulated. The footing and slab must be
insulated both vertically and horizontally in many cases. The
International Residential Building Code requires the following:
Vertical wall insulation of frost protected shallow foundations that
adjoin (point of attachment) a slab-on-ground foundation that does not
have a monthly mean temperatures maintained at a minimum 64 degrees are
required to have insulation. Vertical wall insulation shall extend
between the frost protected shallow foundation and the adjoining slab
foundation. If you are adding a new garage to an existing heated
structure, horizontal and vertical insulation is not required between
the frost-protected shallow foundation. An exception to this is if the
new attached garage forms an inside corner, only horizontal insulation
is required in that instance.
All horizontal insulation placed less than 12 inches below the ground
surface or that portion of horizontal insulation that extends more than
24 inches from the foundation edge can be insulated by the concrete
foundation. Standard garage foundations have footings that are 16”x20”
and a standard concrete slab is 4” thick in Virginia. Therefore,
insulation is not required in these instances.
Each property and garage project is unique in some way. H.W.
Enterprises, Inc. has been building garages, barns and additions for
over 59 years and no two building plans were the same. Call a
professional who knows State and Federal building codes. Call H.W. Enterprises, Inc. in Newport News, VA at 757-595-4562 or 757-696-1927.