What You
Will Be Doing
Heat naturally flows from a warmer area to a
cooler one. It does this in only three ways:
conduction, where heat is transferred directly
from mass to mass; convection, the movement of
heated air from one space to another (hot air
rises, heavier cool air sinks); and radiation,
which simply means that any warm. body gives off
heat toward a cooler one
The
function of insulation is to minimize the
radiation and convection transfer of heat with a
minimum of solid conduction so that our homes
stay warmer in cool weather and cooler in warm
weather.
In this
section we review the merits and uses of various
types of well-known insulations and inform you
on how best to evaluate R-values. |
R stands for 'resistance to heat flow.' The greater the
R-value, the greater the insulative power. R-value
requirements depend on factors such as local climate and
the surface you are insulating (walls, ceiling, floor,
etc.) and will be regulated by your local building code.
I suggest you contact the office of your city or county
building inspector for the requirements of your area.
Each region of the country has different requirements
for adequate amounts of insulation.
In many areas,
local utility companies will offer helpful suggestions
on how to reduce your energy bills. Many will arrange to
have an expert come to your home to point out areas that
need to be insulated or weatherized. Often there is no
charge for this service and it may even lead to low- or
no-interest loan programs you may be eligible for. Also,
state or federal tax credits may apply.
Check with your
State Energy Commission, local power company, or local
building materials dealer or home center for the optimum
R-value in your region.
Safety
Safe-use
practices are important when you work with any type of
insulation.
- Dust mask
and goggles are necessary for work with all types of
insulation, or when sawing wood.
- Fully cover
your body, if possible long sleeves, a hood, long
pants, and gloves. Insulating materials are skin
irritants.
- Always use
the correct tool for the job.
- Be sure
power tools are properly grounded.
- Watch power
cord placement so that it does not interfere with
the tool's operation.
- A hard hat
should be worn, since roofing nails may be sticking
through the sheathing.
- If you are
not allergic to tetanus shots, be sure yours is
current. There are usually exposed, rusty nails in
an old attic.
- Keep the
insulation clear (3" or so) from objects that
transfer heat to reduce fire hazards, and install
sheet metal baffles around recessed light fixtures,
chimneys, and flues.
- In older
homes with possible frayed wires, do not allow the
aluminum vapor barrier of batt insulation to come in
contact with the wire, since it could short circuit
- Working in
attics or other hot areas can cause loss of body
salt by excessive sweating. Consider taking salt
tablets.
- When
working outside on a roof, wear shoes or boots with
rubber soles; stay clear of power lines; secure
extension ladders with safety hooks that clamp over
the ridge; and delay your work until the roof is
free from dampness of rain, frost snow, or dew.
- When
working high on the outside of the house, I suggest
you rent scaffolding to provide a balanced, level
working surface.
- Do not step
through attic floor joists onto the ceiling of the
room below. It will give way.
- Some types
of insulation are flammable. Check with your local
building department and fire department for special
application precautions or restrictions.
Useful Terms
Caulk.
A pliable material, usually forced into a gap or crack
with a gun or pressurized can, hardens into an effective
seal against air and moisture infiltration.
Cellulose.
Blown-in or loose, consists of rock wool, glass fiber,
vermiculite, and/or perlite. Use this in floors, walls,
and hard-to-reach places. This type of insulation is
poured between joists or blown in with special equipment
It is best suited for use in irregular-shaped areas and
is the best option for blowing into existing finished
walls.
Fiberglass.
Blankets or batts, a \widely used insulator for walls,
floors, ceilings, roofs, and attics. Fitted and stapled
easily between studs, joists, and beams, I feel it is
best suited for the do-it-yourselfer.
Flexi-vent.
A waffle-like strip of plastic designed to allow air
circulation to carry away moisture that could build up
under insulation.
Foam.
Extruded polystyrene, isocyanurate board, and fiberglass
board. These rigid panels are used on unfinished walls,
in new construction, or on basement and masonry walls or
exterior surfaces. The panels are glued or cut to
friction fit between studs, joists, or furring strips
and must be covered \with drywall or paneling for fire
safety. They offer a high insulating value for a
relatively thin material, but are highly flammable, and
some chemically based sprays or foams may discharge
poisonous films over a period of time. Be sure to use a
closed-cell, waterproof rigid panel in exterior
applications or in high moisture areas.
Furring.
Strips of wood used to level out a surface prior to
finishing.
Shims.
Thin wedges of wood used to bring furring strips level
with each other when used on an uneven wall.
Silicate
compound. Made of glass and sand. It does not burn,
release toxic fumes, nor attract vermin. It comes in
lightweight easy-to-handle bags and should be used in
the same manner as loose fill or cellulose.
Vapor barrier.
Most common is a 6 mi. sheet of plastic attached over
insulation to eliminate moisture infiltration and
deterioration of insulation.
Tip :
Working in your attic is hot and tiring. Try to work
early in the morning before it gets too hot. Carry a
spray container of cold water to spray on yourself and
your fogged-up goggles. |
