Radiant Barrier Paint Spray vs.
Radiant Barrier Foil
What is
the difference between Radiant Barrier Paint and Radiant
Barrier Foil? Both the radiant
barrier spray paint and
the radiant barrier foil "Reflect" or
will not "Emit" attic radiant heat. The best available radiant
barrier paint will reflect about 75% of the radiant heat
transfer and the radiant barrier foil
will reflect about
97%
of
the
radiant
heat
transfer. Radiant Barrier Foil is actually
the "Best" radiant
barrier. You can either install it yourself or hire a professional
installer who uses our foil insulation.
What is Radiant Barrier Paint? Radiant
Barrier Spray Paint is essentially "liquid foil". All Radiant
Barrier Paints are different, but basically pure aluminum is ground
into a
powder and put into a clear paint. Once the clear paint dries the aluminum
powder forms a layer of aluminum. The best radiant barrier
spray spray
is only available to commercial contractors,
and
is an environmentally safe, water-based low-e paint called HeatBloc-75,
Radiance
e.25. or
Lo/MIT. When the spray is installed CORRECTLY
it will reflect about 75% of the radiant heat and can be a very good
product. I have personally sprayed hundreds of homes in the Dallas
- Ft Worth DFW area with fairly good results.
Getting good results with radiant
barrier paint assumes a couple of things:
First, that the rafters are being sprayed completely (this
usually
costs more). Second, the paint is being applied with the correct
coverage (many spray contractors put it on too thin or too thick).
Finally,
there are some contractors (even large ones who advertise heavily)
that will cut the paint with
WATER
to
extend the coverage. This is called "Cutting" and it is
cheating to cut costs. As a result, the TRUE
EFFECTIVENESS of
radiant barrier
paint installed by many contractors is really only about 15-40%
reflectivity. The typical consumer can't tell the difference between a good
installation and a poor job without testing.
Finally, Radiant Barrier Spray Paint is NOT a good
Do
It Yourself Project.
The fumes are noxious, you MUST use a VOC Respirator, you need a high-end airless
spray rig, know what size spray tip to use and the proper pressure to get correct
coverage and eliminate cloggage. Most people who try to do it themselves will
actually blow too much paint and the material cost alone wil be over .30/ft.
The radiant barrier foil cost is less than .13/ft. Painting
with a roller is impossible since there are thousands of nails sticking through
the roof deck and using a brush would take forever.
Different Brands of Radiant Barrier
Spray Paint and Test Results. Many companies
have developed radiant barrier spray paint. In fact, NONE are
TRUE radiant barriers since they all reflect less than 90% of the heat
which is the definition of a true radiant barrier. They are technically
called "Reflective Coatings" Here is a REPORT
BY RIMA which did independent testing on all the different radiant
barrier paints. Notice that the BEST paint STILL emits 22% of the
radiant heat compared to only 3% for Radiant Barrier Foil.
Some paints claim to be "Award Winning". Please email me if you can find out what this "Award" is and if it has any significance.
And, the
paint tests were on perfectly applied smooth samples under laboratory
conditions - not
your attic. Your attic is made up of porous wood that loves
to soak up paint and NOT keep it on the surface to create a smooth,
shiny
film
required
to be fully effective. In order for paint to come close to the tested
emissivity rating the wood surface MUST be primed with a primer/base
coat of paint first.
Product
Manufacturer/Distributor
Emittance -LOWER
is BETTER
Radiant
Barrier Foil Insulation
.03 Lowest
Possible - BEST
Radiance e-0.25
Chemrex - Now owned by BASF
.23
HeatBloc-75
STS Coatings
.22
E-Barrier
Sherwin Williams
.36
Therma-Guard Silver
United Community Services of America
.57
LO/MIT I II
Solec-Solare Energy Corp
.23
HeatShield R-20
Kwik Co
.90 - Highest Tested-WORST
Radiosity 3000
Green Building Supply
.89
Hy-Tech Barrier Coat #85 - A
Hy-Tech
.66
Hy-Tech Barrier Coat #85 - B
Hy-Tech
.70
Insuladd-RBC
Tech Traders
.59
Koolcoat
Pawnee Specialties
.86
"FREE" Solar Attic
Fans and other incentives. Here
is where the problem occurs. If you put the paint on too thin, add
water or use an inferior "cheap" paint, then customers do not
get the "cool" attic
they are promised. So, some companies have resorted to doing
things
like
giving away "FREE" solar
fans. Yes, if you put an attic fan in the attic it will decrease
the attic temperature but a fan will not stop any radiant heat transfer.
It's actually a little tricky. A cooler attic is nice, but what we
really need to do is reduce the temperature of the insulation.
Who Do We Recommend? There
are some very good radiant barrier spray installers. Unfortunately
there are some that are not very good. The problem
is you are not sure which one is coming to your house. Therefore,
I do
not endorse any particular
company. If you are going to have the spray method done follow this
advise: Use one of the top-rated radiant barrier paints above. CHECK
for factory sealed/labeled containers that are opened on site. NO premixed
paint
in generic buckets.
COUNT
the
number
of
gallons. It is hard to really estimate but if they are putting it on
at 500-1000 ft./gallon it will not get the results promised. INSPECT
Physically climb back into some of the dark corners of your attic with
a flashlight and digital camera. Take some pictures and see if they
got the whole roof. Agree to hold back partial payment until YOU are
satisfied. I hate to be so critical but I've seen so many bad installations
it is pretty common. I once had an installer who worked for
me tell that the prior company he worked for told him that they would
rather send him back on the 1 in 20 customers that complained rather
then for him to do it right with the proper amount of paint the first
time.
Also, ask for quote to spray the entire rafers with
the deck AND how much a to apply a primer coat before the radiant
barrier paint. This will give a better comparison between
the spray and foil. Often, the price to include the full rafter
and apply primer is MORE than you can have the foil professionally installed.
Why Use Radiant Barrier Foil? Basically
you are counting on the PRODUCT to do the work not a PERSON. If the
foil is installed somewhere between the roof or rafters and the insulation
it WILL reflect 97% of the radiant heat. This is indisputable
- Radiant Barrier Foil works! And, It is actually difficult
to install the foil wrong. This is the
difference between Quality Assurance and Quality Control. You can ASSURE
that
reflective foil will
work. You can only HOPE that the Radiant Barrier Spray is installed
correctly. We no longer install radiant barrier paint. We only sell
radiant barrier reflective foil insulation to do-it-yourselfers and
professional installers.
