Most buyers treat the decision to add side panels as a cosmetic upgrade. It is not. A metal carport with sides is a structurally different product than an open-leg carport, one with a different wind-l...
Most buyers treat the decision to add side panels as a cosmetic upgrade. It is not. A metal carport with sides is a structurally different product than an open-leg carport, one with a different wind-load profile, different anchoring requirements, and in many wind-zone states, different permitting obligations that can make enclosed sides effectively non-optional. Get that specification wrong in either direction and the consequences are real. Under-specify in a high-wind region and you risk structural failure. Over-specify on a low-exposure site and you absorb unnecessary cost that never pays back. This guide treats the sides decision as what it actually is: an engineering question driven by wind exposure, regional code requirements, and security criteria. Working through the sections below, you will learn how open and enclosed carports differ structurally, how wind-load ratings work and why your location determines your floor, where codes mandate enclosed sides outright, how anchoring method shapes total wind resistance, and how to confirm whether certified drawings are required before you order. By the end, you will have a working specification framework rather than a list of features to compare. Open Legs vs. Enclosed Sides: What Actually Changes Structurally The physics here is straightforward and consequential. An open-leg carport lets wind pass beneath and through the structure; the frame intercepts relatively little of that energy. Add metal carport siding and the equation changes entirely. Those panels become a continuous surface that catches the full force of the wind and converts it into direct lateral load, pushing against the frame, transferring stress down through the footings, and pulling hard against every anchor point. The structure is no longer deflecting wind; it is resisting it. That distinction drives every specification decision that follows. Adding side panels requires a genuine re-evaluation of frame gauge, anchor type, and bracing configuration, not a simple add-on order. The wind-load engineering profile of the structure changes materially, and treating it as anything less creates a mismatch between what the frame is rated to handle and what the environment will actually deliver. This is why a 12x20 metal carport with sides and a 12x20 open-leg unit are structurally distinct products. They share a footprint and a roof, but they perform differently under identical wind conditions. Specifying one when you need the other is not a minor oversight; it is an engineering error with real consequences during the next significant storm. Cardinal Carports addresses this load environment with a tubular steel framing system carrying a galvanized finish for corrosion resistance. Cardinal Carports uses tubular steel framing with a galvanized finish; frame gauge options include a standard-duty and a heavy-duty 12-gauge upgrade for higher-load applications. Cardinal Carports offers frame upgrade options for higher-load and certified applications, and the heavier gauge becomes the appropriate specification once side panels are added in anything above a moderate wind zone. Cardinal Carports includes peak braces and corner braces as part of its standard framing system. That detail matters more once sides are added, because enclosed siding increases the lateral load paths through the structure. Bracing that adequately handles an open-leg configuration is doing more work once those panels are in place, and having it built in from the start is a meaningful structural advantage rather than an afterthought. The code dimension compounds everything. Shifting from an open to an enclosed configuration changes the structure's exposure category under most building code frameworks, often triggering different permitting thresholds and, in many jurisdictions, a requirement for engineered drawings. That paperwork requirement is the subject of later sections, but its root cause is here: wind loads on non-building structures are treated differently by code once enclosure enters the picture, and buyers who understand that early avoid the costly surprise of discovering it after the order is placed. Wind Load Fundamentals Every Buyer Needs to Know Before Specifying Understanding how that structural shift translates into measurable load is where most buyers lose the thread. Wind load is the force wind exerts on a structure, expressed in pounds per square foot (psf). Four variables determine the actual psf a structure must resist: geographic location, building height, terrain exposure category, and the structure's own design profile, including whether sides are enclosed or open. Wind Speed and Pressure Are Not the Same Number The most consequential misconception buyers carry into the specification process is treating mph and psf as proportional. They are not. Wind pressure increases with the square of wind speed, so a relatively modest speed increase produces a disproportionately larger pressure load. As the under-specification case study below demonstrates, a 28% speed gap produces a far larger pressure gap, pressure scales with the square of wind speed. Snow Load Is a Separate, Compounding Requirement In cold-weather regions, ground snow load adds a second psf requirement that must be certified independently of wind. Standard certification tiers typically run from 20 psf (moderate climates) through 30, 40, and 60 psf, with specialty certification available up to 90 psf for extreme high-mountain applications. Buyers in the Mountain West or Upper Midwest often need to satisfy both a high wind-speed rating and a heavy snow-load rating simultaneously, which drives frame and anchor decisions beyond what either requirement would impose alone. The Full System Must Be Specified Together Frame gauge is one variable in a system that also includes bracing configuration, anchor type, and on-center spacing. A heavy-gauge frame anchored inadequately still fails under lateral load. Concrete anchors deliver the highest uplift resistance and are typically required for certified applications; ground anchors introduce soil-composition variables that affect holding capacity under sustained loading. Upgrading the frame without confirming the anchor specification addresses only half the equation. The single most reliable safeguard is contacting the local building department before requesting a quote. Buyers who estimate their wind zone from a map or a neighbor's permit have ordered to the wrong standard before the first measurement is taken. What Under-Specification Actually Looks Like: A 20x20 Case Study Those fundamentals matter most when they go unverified. A case surfaced in a metal carport buyer community puts the cost of skipping the code check in concrete terms. A buyer ordered a 20x20x9 carport rated for 90 mph and 20 psf ground snow load, based on their own estimate of what their county required. The actual county standard was 115 mph and 40 psf, standards that had been on the books unchanged for more than five years. The buyer did not discover this before ordering. Certified engineered drawings for the compliant specification were quoted separately at approximately $600, a line item that had no place in the original budget. The 28% wind-speed gap is not a minor rounding error. Because wind pressure scales with the square of wind speed, a 28% increase in required wind speed translates to a dramatically larger increase in wind pressure load on the structure, because pressure scales with the square of wind speed. A frame engineered for 90 mph is not marginally undersized for 115 mph; it is a structural failure waiting to happen and a permit denial that stops installation on day one. The snow load mismatch compounds the problem: 20 psf versus 40 psf is a doubling of the design snow load, affecting every connection point in the frame. This is not an edge-case scenario. Permitting enforcement for wind and snow loads is actively rigorous across jurisdictions, and local building…