A rainscreen is an exterior wall built as two layers — an outer cladding and an inner assembly — separated by a cavity sized for the passive removal of liquid water and water vapor. Instead of trusting one sealed surface to stop every drop, the wall manages water through drainage, ventilation and pressure equalization. It's the system we build across DC, Maryland and Virginia.
The Rainscreen Association in North America (RAiNA) describes a rainscreen as an assembly applied to an exterior wall consisting of an outer layer, an inner layer, and a cavity between them sufficient for the passive removal of liquid water and water vapor. That cavity is the whole idea: it gives water somewhere to go and the wall a way to dry.
A face-sealed wall asks a single outer surface to be perfect forever. A rainscreen assumes some water will always get past the cladding — through joints, around fasteners, in wind-driven rain — and is built to drain it away and ventilate the wall dry before it can do harm. Behind the cavity, a continuous weather-resistive barrier is the real line of defense, and the cladding becomes a durable, good-looking screen rather than the only thing standing between the building and the weather.
That distinction matters most in climates like ours. The Mid-Atlantic pushes humid summers, heavy rain and winter freeze–thaw cycles at a building in turn — conditions where a wall's capacity to drain and dry, not just to repel, is what keeps the structure sound over decades.
Five layers, working from the weather toward the structure. Hover or tap a number to walk through the assembly.
Fig. 01 — Drained & back-ventilated rainscreen assembly
A complete rainscreen is more than a panel. Each layer has a job, and the performance lives in how they're detailed together.
The outer screen that deflects the bulk of the rain and gives the building its face. Open or closed joints, in any of six panel materials.
The defining gap. It drains water, ventilates the wall so it dries, and lets air pressure equalize across the cladding.
The continuous water-tight membrane behind the cavity — the surface that genuinely keeps water out, with the cavity as its drainage path.
An unbroken exterior insulation layer that minimizes thermal bridging and improves the envelope's energy performance.
Where the climate and assembly call for it, a vapor retarder manages where moisture can move through the wall.
The stud or CMU backup the system anchors to, plus the sub-framing that holds the cladding off the wall and forms the cavity.
Three approaches to the same goal, chosen by exposure, building height and architecture.
A cavity open at the top and bottom keeps air moving continuously behind the cladding, so incidental moisture evaporates and the wall stays dry.
Adds a dedicated drainage path to the ventilated cavity: water drains away down the back of the panel while air still circulates. The most common DMV approach.
Compartmentalizing the cavity balances wind pressure across the cladding, so wind-driven rain isn't forced through the joints — ideal for taller and high-exposure buildings.
DMV in practice
On a Mount Pleasant project here in the District, open-joint panels were held about a half-inch off the wall with roughly three-eighths-inch gaps between them. The joints look like they invite rain in — but at that spacing they equalize air pressure across the panel, so wind-driven water isn't pushed through. Anything that does get past drains down the back of the panels or evaporates, and a high-performance waterproof membrane behind the cavity does the real work of keeping the building dry. The payoff is both performance and a clean, gridded, distinctly modern façade.
Talk through your projectEvery system above can be built in any of these. Each has its own strengths for the DMV climate and building type.
Common questions from architects, builders and owners across the DMV.
Yes — humid, rainy climates are exactly what they're for. Open joints look like they invite water in, but the gap behind the cladding equalizes air pressure so wind-driven rain isn't pushed through, and any water that does pass drains down the cavity and evaporates. In the Mid-Atlantic's wet summers and freeze–thaw winters, the assembly's ability to drain and dry is what protects the wall.
Vented and drained / back-ventilated (DBV) systems are the most common across the DMV. Vented assemblies keep air moving through a continuous cavity; drained and back-ventilated assemblies add a dedicated drainage path while air circulates behind the panel. For taller or high-wind buildings, pressure-equalized systems compartmentalize the cavity to balance wind pressure across the cladding.
Fiber cement, terracotta, metal composite and metal plate, HPL and UHPC all perform well here. Fiber cement is the durable, fire-resistant workhorse; terracotta holds color and integrity for decades on institutional work; metal plate and composite suit government and healthcare buildings; HPL and UHPC offer modern, low-maintenance finishes. The right choice depends on the building's exposure, use and architecture.
Continuous exterior insulation behind the cladding helps projects meet energy-code requirements and can contribute toward LEED credits, which matters for commercial work in DC and Maryland. Assemblies are also detailed for the wind, fire and moisture provisions that apply to the building's type and height.
Look for fluency in building science and careful membrane detailing, not just panel installation. The weather-resistive barrier behind the cavity is the line that actually keeps the building dry, so the transitions at windows, parapets and penetrations are where a good installer earns their keep. End-to-end envelope coordination avoids the gaps that open up between trades.
Yes. Open-joint rainscreens — panels held off the wall with deliberate reveals between them — give a clean, gridded, contemporary façade and suit modern infill and institutional buildings across DC, Maryland and Virginia. The look is a direct expression of how the system manages water and pressure, so the aesthetic and the performance come together.
Tell us about the building and the look you're after. We'll help you land on the right system, material and detailing.
