Distribution box
A 5"×5" FRP extrusion at the top of each column handles structure, anchoring, and electrical distribution in one aligned component.
Baldwin pergola engineering uses ASCE/SEI 7-22 for wind and snow loading, with project-specific exposure category, risk category, ground snow load, and site conditions coordinated before fabrication.
Wind, snow, and loading criteria for permitted and commercial structures.
3-second gust basis by exposure and risk category, with upgrade paths for higher exposure.
IBC limit for pergola members; standard systems are calculated with substantial reserve.
Standard twin 2×8 FRP system against a 2.5 minimum factor of safety.
| Loading standard | ASCE/SEI 7-22 |
|---|---|
| Standard wind design | 130 mph, 3-second gust by exposure and risk category |
| Deflection limit | L/180 per IBC; standard twin 2×8 FRP system calculated far beyond that threshold |
| Factor of safety | FRP beam flexure FS = 6.3 against a 2.5 minimum |
| Upgrade paths | Four wet-set rods per column, 3/4" or 1" stainless rod, aluminum beams, additional keystone fasteners |
Structural engineering is performed by a licensed PE with a Connecticut DOT bridge-inspection background, with footing design support from a licensed soil engineer. Licensure coverage spans 40 states.
The CNC-machined notches mechanically interlock rafters, purlins, and beams so the assembly behaves as a partial composite box-girder rather than a set of independent sticks.
| Tensile strength | 30,000 psi · ASTM D638 |
|---|---|
| Compressive strength | 30,000 psi · ASTM D695 |
| Flexural strength | 30,000 psi · ASTM D790 |
| Density | 0.065 lb/in³ · ASTM D792 |
| Water absorption | 0.15% max in 24 hr · ASTM D570 |
| Fire classification | NFPA Class A / UBC Class 1 · ASTM E84-01 |
Interlocking notched rafters and purlins add rigidity and produce a clean assembled look. The notch bearing prevents relative movement; the stainless screw at each crossing locks the assembly into a three-dimensional space frame.
Open pergolas experience significant net uplift. The column-to-footing and beam-to-column connections are usually the governing elements — not the beam span.
A 5"×5" FRP extrusion at the top of each column handles structure, anchoring, and electrical distribution in one aligned component.
Drill-and-anchor placement after the footing cures allows exact column positioning. Simpson AT-3G adhesive, stainless stud, and 100 ft-lb tensioning put the column in permanent compression.
On curved aluminum pergolas, the horseshoe keystone converts beam-end uplift from screws in tension to screws in shear — approximately 9,600 lb uplift capacity in the tested configuration.
Wiring routes through hollow FRP columns, beams, and rafters. Downlights, uplights, fans, outlets, switches, heaters, and AV pathways can be integrated without exposed conduit.
FRP ledger, HDPE mounting blocks, bottom-notched rafters and purlins, and weep paths keep water moving. Apply silicone sealant at the top edge of the ledger only — do not caulk the ends or bottom.
Climate-controlled booth, Benjamin Moore exterior system, custom color matching, seven-day minimum cure, and project-specified commercial coatings when required.
In-house shop drawings are available with DWG, DXF, and PDF files upon request. For permitted work, the package can include PE-stamped drawings, structural calculations, footing design support, ASTM references, and connection details.