What you can build yourself and what requires a contractor

A patio cover is a permanent or semi-permanent structure attached to your home that shades an outdoor seating area. You can build straightforward versions yourself — a basic lattice frame or post-and-beam shade structure — but anything that requires electrical work, ties into your roof, or needs to support heavy snow load should go to a licensed contractor. The line between DIY and professional work depends on your local building code, the complexity of the attachment, and whether the structure needs a permit.

Most jurisdictions require a permit for any patio cover that is larger than a certain size (often 200 square feet) or that attaches to the house. Even if your cover is small enough to skip a permit, building it wrong can damage your home's foundation, create water leaks, or fail under wind or snow. Before you start, check with your local building department about what size and type of structure needs approval.

Key Takeaways

  • straightforward freestanding lattice or shade cloth structures under 200 square feet often do not require a permit, but attached covers almost always do.
  • Attaching a cover to your house requires flashing and proper waterproofing where it meets the roof or wall, or water will leak into your home.
  • Post footings must go below the frost line in your area — typically 12 to 48 inches deep depending on your climate — or the structure will shift and crack.
  • Electrical work, gas lines, or structural ties to your roof should be done by a licensed contractor, not a homeowner.
  • Building codes specify how much wind and snow load your cover must withstand, which determines post size, spacing, and foundation depth.

Freestanding covers you can build without a permit

A freestanding patio cover sits on its own posts and does not attach to your house. These are the easiest DIY option because they do not require flashing, do not tie into your roof, and often fall outside permit requirements if they are under a certain size. Check your local code — many jurisdictions allow structures under 120 to 200 square feet without a permit, though some require one regardless of size.

The basic structure is four or more posts set in concrete footings, connected by beams, with rafters and shade material on top. You will need a level site, a post-hole digger or auger, concrete mix, pressure-treated lumber, a circular saw, a drill, and basic carpentry tools. The hardest part is getting the posts perfectly vertical and the footings deep enough. Posts must sit below your local frost line — the depth at which soil does not freeze in winter. If a footing is too shallow, frost heave will push the post up and crack the structure. Frost line depth varies from 12 inches in warm climates to 48 inches in cold ones; your local building department or a soil engineer can tell you the depth for your area.

Dig holes at least 3 feet deep in cold climates, 2 feet in moderate ones. Set posts in concrete that extends slightly above grade so water does not pool at the base. Use a level on two sides of each post before the concrete sets. Once the concrete cures (usually 48 hours), attach beams with bolts or lag screws, never nails. Shade material can be wood slats, lattice, shade cloth, or polycarbonate panels — all are fastened to the rafters with screws.

Attached covers that need flashing and a permit

An attached patio cover connects to your house, usually along the wall or roof line. This is where most DIY projects go wrong, because the connection must be waterproof or rain will run down the inside of your wall and rot the framing. Your local building department will require a permit and will inspect the flashing — the metal or rubber seal where the cover meets the house.

The cover attaches to the house with a ledger board — a horizontal beam bolted to the rim joist (the beam that runs along the top of your foundation). The ledger must be bolted through the rim joist into the band board or header, not just screwed into the house's siding. Bolts go every 16 inches, and the ledger must sit on top of the flashing so water runs over it, not behind it. If you bolt the ledger directly to the siding, water will get trapped behind it and rot the house framing.

Flashing is a bent metal or rubber strip that slides under the house's siding and over the top of the ledger board. It directs water down the outside of the ledger instead of behind it. The flashing must extend at least 4 inches up the wall and be sealed with caulk rated for exterior use. If your house has brick or stone, the flashing must be set into a mortar joint, which usually requires a mason. Many DIY covers leak because the flashing was installed wrong or the caulk failed. If you are not confident in waterproofing, hire a contractor for the ledger and flashing, then build the rest yourself.

Posts, footings, and foundation depth

The foundation is the most critical part of any patio cover, and it is where most DIY mistakes happen. Posts must be set in concrete footings that go below the frost line, or the structure will heave and crack. Frost heave occurs when soil freezes, expands, and pushes the post up. When the soil thaws, the post settles unevenly, and the structure cracks or becomes unstable.

Dig holes at least 12 inches in diameter and deep enough that the bottom is below the frost line. In cold climates, this can be 36 to 48 inches. In moderate climates, 24 to 30 inches is usually enough. If you are not sure, call your local building department or a soil engineer — the cost of a phone call is less than the cost of rebuilding a failed structure. Pour concrete into the hole, set the post in the concrete while it is still wet, and use a level to make sure the post is vertical. Concrete takes 48 to 72 hours to cure fully; do not attach beams until it has cured.

Posts should be pressure-treated lumber rated for ground contact, typically 4x4 or 6x6 depending on the span and load. Do not use untreated wood or standard lumber — it will rot. Space posts no more than 12 feet apart for most climates, but check your local code, which may require closer spacing if you live in a high-wind or heavy-snow area.

Shade materials and roof options

Once the frame is built, you have several choices for shade material, each with different costs and maintenance needs. Wood slats are the most common — 2x6 or 2x8 boards spaced 1 to 2 inches apart. They provide dappled shade, look finished, and are straightforward to replace if one rots. Space them running east to west so the sun angle changes the amount of shade through the day. Wood needs to be sealed or stained every few years to prevent rot.

Lattice is lighter and cheaper than solid slats but provides less shade. It is good for climbing vines and looks decorative. Shade cloth is a woven fabric that blocks 30 to 90 percent of sunlight depending on the weave. It is inexpensive and straightforward to install but needs to be replaced every 5 to 10 years and can tear in high wind. Polycarbonate panels are rigid plastic sheets that are clear, translucent, or opaque. They are durable and provide good shade but can yellow over time and are more expensive than cloth or slats.

If you want a solid roof that sheds rain, you will need metal roofing or shingles, which requires more structural support and usually a contractor. A solid roof also needs gutters and downspouts to direct water away from the house, and the weight of the roof material may require deeper footings and larger posts.

Building permits and inspections

Most attached patio covers and any cover over a certain size requires a building permit. The permit process varies by jurisdiction but usually involves submitting a site plan, a drawing of the structure, and details about the posts, footings, and attachment method. The building department will review the plans to make sure the structure meets code, then issue a permit. You will pay a fee, which is usually based on the square footage of the cover.

Once you start building, the inspector will visit to check the footings before you pour concrete, then again after the frame is up to verify that posts are vertical, bolts are tight, and flashing is installed correctly. If you skip the permit and the inspector finds an unpermitted structure, you may be ordered to remove it or bring it into compliance, which can be expensive. Unpermitted work can also affect your home's resale value and your homeowner's insurance.

If you are unsure whether your cover needs a permit, call your local building department and describe what you want to build. They will tell you whether a permit is required and what the inspection process looks like. This conversation is free and will save you from building something that fails inspection.

When to hire a contractor instead

Hire a contractor if your cover needs to tie into your roof, if it requires electrical work (for lights or fans), if it is in a high-wind or heavy-snow area, or if you are not confident in your carpentry skills. A contractor will handle the permit, design the structure to meet local code, and take responsibility if something fails. They will also know the frost line depth, the wind and snow loads for your area, and the flashing details that prevent leaks.

Contractors typically charge by the square foot or by the hour. A straightforward attached cover might cost $3,000 to $8,000 installed, depending on the size and materials. A freestanding cover is usually cheaper because it does not require flashing. Get quotes from at least three contractors and ask to see examples of their work. Make sure they are licensed and insured, and ask whether the permit is included in the price.

Frequently Asked Questions

Do I need a permit for a small patio cover?

Most jurisdictions require a permit for any cover attached to the house, regardless of size. Freestanding covers under 120 to 200 square feet often do not need a permit, but this varies by location. Call your local building department to confirm what applies to your project.

How deep should post footings be?

Footings must go below the frost line, which is the depth at which soil freezes in winter. This ranges from 12 inches in warm climates to 48 inches in cold ones. Your local building department can tell you the frost line depth for your area. If you dig too shallow, frost heave will crack the structure.

Can I attach a patio cover to my roof?

You can, but it requires proper flashing and usually a contractor. The attachment must be waterproof, or rain will leak into your home. If you want to tie into the roof, hire a licensed contractor who knows your local code and can may provide the work against leaks.

What is the best shade material for a patio cover?

Wood slats are durable and look finished but need sealing every few years. Shade cloth is cheap and straightforward to install but lasts 5 to 10 years. Polycarbonate panels are rigid and long-lasting but more expensive. Choose based on your budget, how much shade you want, and how much maintenance you are willing to do.

What happens if I build a patio cover without a permit?

If an inspector finds an unpermitted structure, you may be ordered to remove it or bring it into compliance at your own expense. Unpermitted work can also affect your home's resale value and may not be covered by homeowner's insurance. It is cheaper to get a permit upfront than to deal with these problems later.