Problem
Until today, the vast majority of building construction has utilized foam plastics (i.e. EPS and XPS) or mineral wool for thermal insulation.
Desired properties
Commercially available in 3 to 5 years
Produced from biological / natural processes
Problem
The service life of architectural coatings significantly impacts building maintenance costs. As the majority of installed cost is labor, improvements in quality of materials that reduce the cost of recoating over decades are economically attractive for building owners.
Desired properties
- Cost does not exceed that of currently available top-quality coatings (i.e. $0.30 per square foot)
- Coating can be installed or applied effectively in winter temperatures down to 25°F
Specifications
Category 1: Long-lasting architectural paints / coatings
Reduce building maintenance cost with fewer recoatings
Problem statement
Reduce building maintenance cost with fewer recoatingsThe service life of architectural coatings significantly impacts building maintenance costs. As the majority of installed cost is labor, improvements in quality of materials that reduce the cost of recoating over decades are economically attractive for building owners. Although they are more expensive, top-quality coatings cost 27% less over 25 years because they have 50% more service life.
Estimated 25-year recoating cost for 20,000 square-foot building
| Coating type | Mid-quality | Top-quality | Target | Stretch |
|---|---|---|---|---|
| Materials | $0.20 / sqf | $0.30 / sqf | $1.00 / sqf | $0.30 / sqf |
| Labor | $0.80 / sqf | $0.80 / sqf | $0.80 / sqf | $0.80 / sqf |
| Service life | 4 years | 6 years | 12 years | 12 years |
| 25-year cost | $120,000 | $88,000 | $72,000 | $44,000 |
If the service life of the architectural coating can be extended to 12 years, and the total material cost does not exceed $1.00 per square foot (5 times the cost of traditional architectural coatings), maintenance cost 20,000 square foot commercial building over 25 years can be reduced from $120,000 to $72,000a. Achieving 12 years at similar cost to today’s best-quality coatings would reduce the 25-year cost by half. Larger (particularly tall) buildings have even more savings potential, given higher labor costs for recoating.
Possible approaches
Any solutions that extend the service life of building envelope coatings will be considered. Specific materials of interest include silicone polymer resins, fluorinated polymer resins, and new polymer technologies. For example, a solution could be a water-based resin that can be formulated into a water-based coating.
Known approaches not of interest
Unless significant performance/cost breakthroughs or innovative applications can be achieved, the following materials represent known state-of-the-art and are thus not of interest:
- Acrylic clear coat sealers applied over traditional architectural coatings, thus requiring 2 coats
- Clear sealers such as those utilized by the automobile and fiber cement panel industries
- Resins that can be blended with traditional acrylic polymers for durability, such as water based polyvinylidene fluoride (PVDF), water based fluoroethylene vinyl ether (FEVE), or water based silicone emulsion resins.
Key success criteria
Required:
- The VOC of the formulated product does not exceed 50 g/L
- Gloss ranges of MPI Class 1 and 2 are achievable
- Cost does not exceed 5 times that of mid-quality acrylic coatings (i.e. $1 per square foot or less)
- Formulated coating has superior gloss/color retention, chalk resistance, and yellowing resistance
- Coating can be installed or applied effectively in winter temperatures down to 40°F
Desired:
- Cost does not exceed that of currently available top-quality coatings (i.e. $0.30 per square foot)
- Coating can be installed or applied effectively in winter temperatures down to 25°F
Technical specifications [Cat. 1]: Long-lasting architectural paints / coatings
| Property | Standard | Requirement |
|---|---|---|
| Resistance to wind driven rain | ASTM D6904 | No water penetration @ 2 coats or 1 coat with primer coat |
| Moisture resistance | ASTM D2247 | No deterioration @ 28 days |
| Adhesion to concrete | ASTM D4541 | >200 psi |
| Reaction to fire | ASTM E84 | < 25 Flame spread < 75 Smoke developed |
| Freeze/thaw resistance | ASTM E2485 | Pass 60 cycles |
| Volatile organic compound (VOC) | SCAQMD Rule 1113 | 50 g/L |
| Color retention | ASTM G155 | Superior chalk/yellowing and fade resistance: Delta E < 2 after 5,000 hours (10,000 hours stretch target) of accelerated weathering |
| Formulated cost of coating | Minimize | $1.00 per square foot or less |
| Water vapor permeability (desired, not required) | ASTM E96 Method A | > 10 perms (572 ng/Pa●s●m²) |
| Water absorption (desired, not required) | ASTM C272 | <10% |
| Tensile strength (desired, not required) | ASTM D-412 | >200 psi |
| Gloss ranges (desired, not required) | MPI | Class 1 and 2 |