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18x20 Portable Garages

An 18 x 20 ft garage is the double: two cars side by side, or a pickup beside a boat on its trailer, under one cover. The lead model in this size is the ShelterLogic ShelterTube, a rectangular-tube steel frame (2 x 3 in, 15-gauge) under a triple-layer waterproof cover, rated for a 35 lb per sq ft ground snow load, and for 80 mph winds at 10 ft tall or 70 mph at 12 ft. It has zippered doors at both ends, so you can drive straight through, and comes 10 ft or 12 ft tall in gray or green.

The 10 ft ShelterTube stands 9′10″ tall and the 12 ft one 11′10″, with an 18 ft wide door opening that reaches 108 in at its peak on the 12 ft model — room for a van or a boat on its trailer. The size also includes the ShelterCoat 18x20 peak garage (9 ft or 11 ft) and the Gazebo Penguin Deluxe Double Car Shelter with two windows. One car? See 12x20 garages; for a permanent roof, 20x20 carports and car shelters.

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  1. Gazebo Penguin

    Deluxe Double Car Shelter, 18 × 20 ft, White

    18 × 20 ft Polyethylene cover Freestanding

    Special Price $1,423.95 Regular Price $1,499.00

    Save $75.05

    Freight delivery

  2. ShelterLogic

    ShelterTube Garage, 20 × 18 × 10 ft, Wind and Snow-Load Rated, Grey

    18 × 20 ft Polyethylene cover

    Special Price $2,969.95 Regular Price $3,899.98
    Out of stock
  3. ShelterLogic

    ShelterCoat Peak Garage, 18 × 20 × 9 ft, Grey

    18 × 20 ft Polyethylene cover

    Special Price $1,697.95 Regular Price $3,184.60
    Out of stock
  4. ShelterLogic

    ShelterCoat Peak Garage, 18 × 20 × 11 ft, Grey

    18 × 20 ft Polyethylene cover

    Special Price $1,697.95 Regular Price $3,323.06
    Out of stock
  5. ShelterLogic

    ShelterCoat Peak Garage, 18 × 20 × 11 ft, Green

    18 × 20 ft Polyethylene cover

    Special Price $1,697.95 Regular Price $3,323.06
    Out of stock
  6. ShelterLogic

    ShelterTube Garage, 20 × 18 × 10 ft, Wind and Snow-Load Rated, Green

    18 × 20 ft Polyethylene cover

    Special Price $2,963.95 Regular Price $3,999.98
    Out of stock
  7. ShelterLogic

    ShelterCoat Peak Garage, 18 × 20 × 9 ft, Green

    18 × 20 ft Polyethylene cover

    Special Price $1,697.95 Regular Price $3,184.60
    Out of stock
  8. ShelterLogic

    ShelterTube Garage, 20 × 18 × 12 ft, Wind and Snow-Load Rated, Green

    18 × 20 ft Polyethylene cover

    Special Price $3,165.95 Regular Price $4,199.98
    Out of stock
  9. ShelterLogic

    ShelterTube Garage, 20 × 18 × 12 ft, Wind and Snow-Load Rated, Grey

    18 × 20 ft Polyethylene cover

    Special Price $3,169.95 Regular Price $4,199.98
    Out of stock
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18x20 garage FAQ

Is 18 x 20 big enough for two cars?

Yes, for two cars or small SUVs parked side by side, or one vehicle plus a trailer, a snowblower and a workbench. Inside, the ShelterTube is 19′9″ wide by 18′1″ deep. Leave about 2 ft between the cars and the walls so the doors can open.

Is 20x18 the same as 18x20?

Yes, the same footprint named from a different side. ShelterLogic names the ShelterTube 20x18: 20 ft along the side walls and 18 ft across the ends, where the doors are, so two cars park nose-in through one end.

What is it rated for?

The ShelterTube is rated for a 35 psf ground snow load; the 10 ft model for 80 mph winds and the 12 ft model for 70 mph. Its frame carries a 10-year prorated warranty (full repair or replacement in year 1) and the cover 1 year. The ShelterCoat 18x20 states no rating, and its warranty is 1 year. Snow-load ratings explained shows what 35 psf means where you live; brush heavy snow off any fabric roof.

How is it anchored?

Anchor every leg: to concrete, to ground anchors in soil, or to a pony wall. The ShelterTube goes together with slip-fit joints and self-tapping screws, and our portable garage assembly guide covers the set-up. Check your bylaw first: many municipalities limit the size and season of a temporary shelter.

Read next: the winter car shelter guide and snow-load ratings for carports and garages.