Fire-Hardening a 3,000-Square-Foot Timber-Lagging Wall During a Salinas Bridge Repair

A bridge repair is a good moment to think about fire. While crews rebuilt a structure in Salinas, NanoTech added Class A protection to a 3,000-square-foot timber-lagging wall with Wildfire Shield, folding wildfire mitigation into work that was already underway.

In March 2024, as part of a bridge repair in Salinas, California, NanoTech Materials' Wildfire Shield was applied to a 3,000-square-foot wood timber-lagging wall. American Civil Construction did the work. The fire-resistant coating was meant to protect the structure from wildfire damage and stretch its service life.

Pairing the coating with the repair was the practical move. It put modern fire protection on the wall while crews were already on site, and it strengthened the structure's safety and durability for the community around it.

Project at a glance

Bridge infrastructure with combustible retaining structures

Bridge approaches and embankments often use wood timber lagging to hold back soil and support the roadway. On California's central coast, where wildfire and wildland-urban-interface exposure run high, that combustible timber is a liability near a critical river-and-road crossing. A fire that damages the lagging can threaten the very structure the bridge repair set out to restore.

Doing it once, during the repair

The wall was already open and accessible during the repair, so it was an efficient time to add fire protection. Coordinating the mitigation with the scheduled work used the access and traffic control that were already in place, and it saved a second trip later.

Why combustible lagging is a risk, and how the coating answers it

Wood ignites and chars under radiant heat and direct flame, then spreads fire and loses strength. Intumescent fireproofing only reacts once heating starts, so the substrate can ignite before the coating activates, and the char it forms can smoke and off-gas.

A passive barrier that needs no activation energy

Wildfire Shield protects passively from the moment it cures. Built on NanoTech's patented Insulative Ceramic Particle (ICP) technology, it pairs high emissivity, high reflectivity and low thermal conductivity to reflect and re-radiate heat and slow its path into the wood. That makes a high-temperature thermal barrier with no flame spread and no smoke (ASTM E84 Class A, 0/0).

In testing witnessed by Department of Transportation personnel, coated timber lagging was held under a direct propane-torch flame for 20 minutes while the thermocouples behind the coating stayed near ambient.

Wildfire Shield applied on-site to the bridge's timber lagging

Working with American Civil Construction, the team coated the 3,000-square-foot wall during the bridge repair. They cleaned and moisture-checked the substrate, then built the coating up in passes to the specified dry-film thickness, following the surface of the wall.

What the coating system delivered

•     A Class A coated surface: ASTM E84 Flame Spread 0, Smoke Developed 0

•     Passive, non-sacrificial protection that needs no activation energy

•     Fire protection added without a separate mobilization

•     Longer service life for the timber lagging, supporting the bridge-repair investment

•     A water-based coating with simple water cleanup

•     Backed by NanoTech's 10-year material warranty

Modern fire protection, folded into essential repairs.

Coating the lagging during the bridge repair added wildfire resilience with no separate mobilization, strengthening safety and durability for the surrounding community.

Safety and durability, reinforced in one pass

The wall left the project with Class A passive fire protection and a longer service life, and the mitigation work fit inside the existing schedule.

Salinas points to a cost-effective habit for any DOT: build Wildfire Shield into scheduled bridge and highway work, so fire mitigation rides along with repairs already happening.

What this means for your team

The same outcome reads differently depending on your role. Here is what this project means for the people who own, specify and apply fire-protection coatings.

For DOT structural & fire-protection engineers

Wildfire Shield gives specifiers a documented, independently tested alternative to defaulting to concrete for fire-exposed wooden infrastructure. It is verified to ASTM E84 (Class A, 0/0), plus E119, E162 and E662, and it came through a 20-minute direct flame-impingement test on timber lagging witnessed by Department of Transportation personnel. That is the kind of evidence it takes to qualify a non-traditional material with confidence.

For DOT district managers & budget authorities

Coating in place, or shop-applying off-site, preserves existing timber lagging instead of replacing it with costlier concrete or steel. Wildfire Shield is non-sacrificial and is built to protect the structure across repeated fire events when the system is maintained, so it stretches mitigation budgets across more lane-miles while keeping crews and traffic moving.

For bridge & highway contractors / applicators

Wildfire Shield is sprayed or rolled with common equipment and conforms to the geometry of timber lagging, abutments and fences, with no jacketing or fabrication required. On-site or off-site shop application removes seasonal and just-in-time bottlenecks, and NanoTech's certified-applicator training and supervision keep DOT-specified work on schedule.

Wildfire Shield technical specifications

Wildfire Shield is a water-based, non-sacrificial fire-mitigation coating built on NanoTech's patented Insulative Ceramic Particle (ICP) technology. Key published properties are summarized below; confirm project specifics against the current Technical Data Sheet and SDS.

Frequently asked questions

Why coat the lagging during a bridge repair?

The repair already had site access and traffic control in place, so adding Wildfire Shield avoided a second mobilization. That cut cost and disruption while improving the structure's fire resilience.

How is Wildfire Shield different from intumescent fireproofing?

Intumescent coatings have to be triggered by fire. They char and swell only after the substrate begins to heat, so the wood can ignite before the coating activates, and the char can give off smoke and toxicity. Wildfire Shield is non-sacrificial and works the moment it is applied. Its mix of high emissivity, high reflectivity and low thermal conductivity reflects and re-radiates heat and slows the heat that reaches the wood, with no flame spread and no smoke development (ASTM E84 Class A, 0/0).

Can the coating survive more than one fire?

Yes. Because it is non-sacrificial, Wildfire Shield is designed to protect the underlying structure through repeated wildfire events when the coating system is inspected and maintained. NanoTech recommends yearly inspections for wear, cracking or damage, and worn areas can be touched up by overcoating rather than fully replaced.

How hot can Wildfire Shield withstand?

It withstands direct flame exposure up to 3,272°F (1,800°C). In testing witnessed by Department of Transportation personnel, coated timber lagging was held under a direct propane-torch flame for 20 minutes while the thermocouples behind the coating stayed near ambient.

Is it safe and environmentally responsible?

Wildfire Shield is water-based and non-toxic, with no reportable VOCs and no toxic runoff or leaching, and it is not classified as hazardous for supply or use. It cleans up with water and suits sensitive settings such as national parks and the wildland-urban interface.

Related resources

From NanoTech Materials

•     Wildfire Shield product page

•     Fire Protective Coating System overview

•     Wildfire mitigation applications

•     Industries we serve

•     Resource library and case studies

•     Request a quote or join the certified-applicator network

External references

•     CAL FIRE (California Department of Forestry and Fire Protection)

•     ASTM International fire-test standards

Talk to NanoTech about wildfire protection

Protecting timber lagging, bridges, utility poles, fences or homes in a wildfire-prone area? Talk to NanoTech about Wildfire Shield, or join our certified-applicator network. Call (888) 296-6266, email [email protected], or visit nanotechmaterials.com.

About NanoTech Materials. NanoTech Materials is a Houston-based materials-science company developing advanced coatings for energy efficiency and fire protection. Its Fire Protective Coating System, including Wildfire Shield, is built on patented Insulative Ceramic Particle (ICP) technology to protect critical wooden infrastructure and high-value assets from wildfire, buying time and saving lives.

_{© 2026 NanoTech Materials. All rights reserved. Performance data summarized from NanoTech technical documentation (TDS, SDS, Application & Technical Manual) and the Wildfire Shield Project Portfolio; confirm project-specific details and current published values with a NanoTech representative.}