Deck Cover/Roof Calculator

Depends on the deck's design dead load + the cover's added weight. IRC R301.5 minimum is 10 psf dead load — meaning your deck framing already supports 10 psf of permanent weight (deck boards, railings, baked-in furniture). An open pergola adds 3.5 psf — fits under 10 psf. A gable cover with shingles adds 18.5 psf — DOES NOT fit under 10 psf. The calculator's headroom check flags this. If overbudget, options: (1) build the cover as freestanding next to the deck (separate footings + posts that don't load the deck), (2) reinforce the deck with sister joists + larger beams to add capacity, or (3) downgrade to a lighter cover type.

Open pergola = rafters only, no roof panel. Provides partial shade via rafter spacing (typically 6-12″ between rafters). No rain protection. Cost $20-40/sqft installed. Louvered pergola = motorized aluminum louvers that tilt open or closed. Provides FULL rain protection when louvers closed + full sun when open. Adjustable via remote. Premium brands: Struxure ($100/sqft), Equinox ($90), Renson ($120), Sun Louver ($80). Worth it if you'll use the deck year-round + want rain protection AND open-air feel.

Retractable awning at 1.5 psf — it's mostly cantilevered from the house wall, with no deck-attached structure. Doesn't catch snow (retracts in winter). Best when you want shade on demand without committing to a permanent structure. Trade-off: must be retracted in storms (manual or motorized). Sun Setter + Awntech are the major brands. After retractable awning: open pergola (3.5 psf), polycarbonate patio cover (4 psf), louvered pergola (6.5 psf), lean-to (8 psf), gable (11 psf).

Almost always, yes. Most jurisdictions require a permit for ANY permanent roof structure regardless of size (IRC R105.1). Open pergolas sometimes squeeze under permit-exemption rules (under 200 sqft + un-roofed + freestanding) — but if attached to the house, it almost always needs a permit. Gable + lean-to covers definitely require permit + plan + structural engineer letter. Permit fees $200-1,500 depending on jurisdiction and cover type.

Yes — gable covers are commonly built to match existing house roof pitch + shingle color. The roofing contractor will: (1) tie into the existing house roof valley + flashing, (2) match shingle color/style to the existing house, (3) carry the gable rafters down to the deck or to dedicated posts. Most expensive cover type because of the integration work. Budget extra for siding repair if removing existing siding to tie in.

Depends on the roof panel. Open air + shade cloth (70-95% sun-block fabric) let in light + air. Acrylic + polycarbonate panels are translucent — let in 60-80% of light without UV. Metal pan + shingles are opaque — block 100% of light. For a sunny deck zone you want translucent panels (polycarbonate). For a sun-shaded relaxation zone you want opaque panels (gable with shingles, metal pan). Most modern designs use polycarbonate for the middle ground.

Yes, but with caveats. Premium louvered pergolas (Struxure, Equinox) are engineered for 30-50 psf snow load when louvers are CLOSED. In heavy snow zones (40+ psf) the louvers should be opened to let snow fall through, then closed when not snowing. Some models auto-detect snow and open the louvers. Budget-tier louvered pergolas may not have snow rating — confirm with manufacturer before buying in MN/WI/ME/upstate NY. The Snow Load Calculator gives you your local PSF.

Yes for: gable roof covers (always), lean-to covers above 200 sqft, any cover where the dead-load check flags amber/red, any cover in hurricane wind zones, any cover catching 30+ psf snow load, any cover where the existing deck's structural design is unknown. The engineer letter runs $400-1,500 and is required by most permit offices anyway. The simpler covers (open pergola, polycarbonate patio cover, retractable awning) typically don't need engineering — prescriptive design works.

Yes — toggle the 'screens' option. Adds $14.50/lf of perimeter for screen-in panels (typically aluminum frame + Phifer fiberglass mesh). A 16×12 cover with screen-in panels adds about $810. Creates an enclosed screen room while maintaining outdoor air feel. Most popular with gable + lean-to covers (which already block rain) — combined cost typically $7-12K total for a screen room. Cheaper than a glass sunroom by 5-10×.