Real Challenges. Proven Solutions.
Retrofit projects come with constraints that new construction rarely faces. You're working around existing structures, matching veneer depths, coordinating trades on tight timelines, and meeting current energy codes with assemblies that weren't designed for them. For architects and builders navigating these realities, an exterior wall system that integrates drainage and insulation from the sheathing out makes the difference between a smooth retrofit and one that drags through change orders.
The Old Mill Panel+ Wall System addresses these challenges head-on. It combines EPS foam insulation panels, built-in drainage channels, and precise veneer alignment into a single coordinated assembly. The result is faster dry-in, reduced labor coordination, and code-compliant thermal performance without stacking multiple subcontractors.
How Integrated Drainage Works in Retrofit Wall Systems
Moisture control in retrofit applications differs from new construction. Existing substrates may have variable conditions. Flashing details need to tie into what's already there. Traditional multi-step approaches require a separate weather barrier, drainage mat, and veneer support system, each with its own install sequence and inspection point.
Panel+ simplifies this with cross-drainage channels engineered directly into the EPS foam. These channels run vertically and horizontally across the panel face, allowing water that penetrates the veneer to drain downward and exit at the base of the wall. Because the drainage plane is built into the insulation layer itself, there's no separate mat to install or position.
For retrofit projects, this matters in two ways. First, fewer materials mean less coordination between waterproofing and insulation crews. Second, the integrated drainage plane maintains consistent performance even when installed over substrates with minor irregularities.
According to the U.S. Department of Energy, effective moisture management in exterior walls prevents structural damage, maintains insulation performance, and reduces the risk of mold growth. Panel+ delivers engineer-level moisture control by combining drainage, ventilation, and a properly detailed weather barrier in one tested assembly.
Why Continuous Insulation Matters for Retrofits
Thermal bridging accounts for significant heat loss in buildings with framed walls. When insulation sits only between studs, the framing itself becomes a thermal short circuit. In retrofit scenarios, adding cavity insulation alone rarely achieves meaningful energy performance improvements.
Continuous insulation breaks this pattern by wrapping the entire envelope in an uninterrupted thermal layer. Panel+ delivers R-4.2 per inch at 75°F, with standard thicknesses from 1 inch to 4 inches. That means a 4-inch Panel+ assembly achieves R-16.8 at the panel alone, before counting any existing cavity insulation.
For architects specifying retrofit assemblies, continuous insulation also simplifies code compliance. Current energy codes including IECC and ASHRAE 90.1 increasingly require exterior insulation on wall assemblies. Panel+ meets these requirements while delivering NFPA 285 compliant assemblies for projects requiring fire-tested wall systems.
The challenges of retrofitting with continuous insulation often include attachment complexity and veneer alignment. Panel+ addresses both with integrated alignment guides for thin brick, stone, or tile veneer, eliminating the need for separate support systems.
What Sets Integrated Systems Apart from Multi-Step Assemblies
Traditional retrofit approaches typically involve four to six separate components installed in sequence: weather barrier, insulation board, drainage mat, mechanical fasteners, and veneer support. Each layer requires its own quality control checkpoint. Each trade handoff creates an opportunity for installation error.
Panel+ consolidates these functions. The system includes:
- Old Mill Air & Water Barrier in the fluid-applied adhesive method
- Panel+ EPS foam panels with integrated drainage and ventilation channels
- Built-in veneer alignment for consistent thin brick or stone spacing
- Old Mill Adhesive for panel attachment
This single-source approach reduces material handling, shortens the install sequence, and gives one system warranty to cover the entire assembly. Old Mill Building Products backs Panel+ with a 15-year system warranty.
For builders managing retrofit timelines, the labor savings add up fast. Panel+ reduces installation labor by up to 60 percent compared to traditional lath and scratch methods. Crews move from substrate prep to veneer install faster, which means earlier dry-in and reduced weather exposure for the project.
Installation Methods for Different Retrofit Conditions
Retrofit substrates vary. Some projects involve sound concrete or masonry. Others require attachment over existing sheathing or cladding removal. Panel+ accommodates both scenarios with two approved installation methods.
Fluid-applied adhesive method: Old Mill Air & Water Barrier applies directly to the approved substrate, creating the primary weather barrier. Old Mill Adhesive is then combed vertically with a half-inch notch trowel to form drainage channels before the Panel+ EPS panels are set. This method works well on sound, clean substrates where mechanical fasteners are impractical or undesirable.
Mechanically fastened method: A drainable building wrap installs behind the Panel+ panels, which are then attached with Old Mill washers and approved fasteners. This approach suits retrofits over wood sheathing or where adhesive-only attachment doesn't meet project specifications.
Both methods deliver the same thermal performance and drainage capability. The choice depends on substrate condition, structural attachment requirements, and project-specific details.
Performance Metrics That Matter for Retrofit Specifications
Specifying retrofit wall systems requires clear performance data. Vague claims about "improved efficiency" don't help you demonstrate code compliance or justify material selections to owners.
Panel+ assemblies are NFPA 285 compliant, meeting the standard fire test for exterior wall assemblies with combustible components. This compliance is increasingly required for commercial and mixed-use retrofit projects, particularly those involving multi-story facades or jurisdictions with stricter fire codes.
Energy cost reductions with Panel+ reach up to 40 percent when replacing uninsulated or poorly insulated assemblies. R-values up to R-20 are achievable with 4-inch panel configurations. These numbers translate directly to utility savings and LEED or ENERGY STAR credits for projects pursuing certification.
For labor planning, the 60 percent reduction in installation time compared to traditional methods affects both schedule and budget. Fewer labor hours mean lower soft costs and earlier occupancy dates.
Retrofit Applications Across Building Types
From hospitality and retail to education and healthcare, Old Mill Panel+ shows up where performance and speed matter. Retrofit applications include:
- Multi-family housing: Older apartment buildings with failing EIFS or stucco benefit from complete envelope replacement with Panel+ and thin brick veneer.
- Commercial facades: Office buildings seeking updated aesthetics plus energy performance can achieve both with one assembly.
- Historic renovation: Projects requiring brick appearance without the structural load of full masonry find Panel+ and thin brick an effective solution.
- Retail renovations: Fast turnaround requirements align with Panel+ installation speed.
Panel+ has been used across hundreds of commercial and mixed-use projects to simplify envelope design, meet NFPA 285 requirements, and deliver a masonry finish without complicating the build.
The Result: Integrated Performance for Retrofit Projects
Retrofit wall systems with integrated drainage and continuous insulation address the core challenges architects and builders face: moisture control, thermal performance, code compliance, and installation efficiency. Panel+ delivers all four in a single coordinated system.
What you get with Panel+:
- Continuous insulation with R-4.2 per inch, up to R-20 at 4-inch thickness
- Built-in drainage and ventilation channels for moisture management
- NFPA 285 compliant assemblies for fire-tested performance
- Up to 60 percent labor reduction compared to traditional methods
- 15-year system warranty from a single source
- Real thin brick, stone, or tile finish with built-in alignment
Looking for a retrofit project like yours? Contact Old Mill Building Products for sector-specific examples, technical details, and installation support.
