Coatings
Neil Smit
 |
Seed Newsvine |
Coatings play a key role in our industry — from protecting potentially vulnerable structural material from the elements, to providing valuable energy savings. Let’s take a look at some popular coatings and associated costs.
Coatings for Structural Steel
One of the most important uses for coating applications these days is for reinforcing steel. Consider a suspended slab:
- Concrete has compressive strength but zero tensile strength.
- Reinforcing steel provides the tensile strength in the slab.
- Concrete can be permeable.
- Uncoated reinforcing steel in the slab can rust and lose strength.
- The slab is now vulnerable to damage or collapse.
Applying epoxy coating to reinforcing steel eliminates rusting — and thus the potential of cracking and spalling of slabs, especially those exposed to the weather. The other options, of course, are galvanized or stainless reinforcing steel.
What Will It Cost?
Epoxy-coated reinforcing steel will cost $400 more per ton than non-epoxy coated.
(Source: Means Building Construction Cost Data, 2008)
Surface Coatings
Some epoxy surface coatings are recommended for driveways, pool decks, and tennis courts, too. They are also good for foot traction on commercial and industrial floors. Take your choice of solvent or water-based coatings. Water-based is recommended for indoor use — and is odorless. Heavy-duty epoxy coatings average two to three times as tough as the concrete they’re applied to.
What Will It Cost?
Epoxy-based coating, 2 Coats: $.56/SF
(Source: Means Building Construction Cost Data, 2008)
Roof Coatings: Green Alternatives
Even in mild climates, the sun beating down on a roof all day can cause it to reach extreme temperatures and drive considerable heat into a building via conduction. Installing a reflective roof (or painting an existing roof with a reflective coating), is a key means of reducing heat gain.
Today the US Environmental Protection Agency (EPA) is touting white reflective acrylic coating of roof systems, which can be applied to either new or existing roofs. The fact that it’s white means it reflects the heat and saves energy.
Reflective roof coatings not only help prevent the building from getting hot, but also reduce heat island effects and prolong the life of the roof. Multiple studies of buildings in hot climates (including California, Texas, and Florida) have documented 10%–50% energy savings when roofs were retrofitted with reflective coatings.
Reflective coatings can be applied to any roof surface and can reflect about 82% of total sunlight. Non-petroleum, water-based reflective coatings are the best environmental choice. However, modeling indicates that in colder climates, such as Colorado, increased winter heating energy is more than the savings in summer cooling energy.
What Will It Cost?
Fibrated aluminum coating $.23/SF
