How to Build a Pergola Attached to the House: Instructions and Drawings

Need to know how to build a pergola attached to the house? Want to build a DIY pergola? This simple design can be expanded or shrunk as necessary to fit the space you have over your patio or deck.

Introduction

Pergolas provide shade and a place to hang potted plants over patios and decks. If you choose to attach your pergola to the house, it must be anchored to the house framing and not the trim, siding, or fascia boards. Since attaching a pergola to the house framing is a structural change, you’ll need a building permit in most cases. Before you start building or buy any materials, check with your local building department for local code, permits, and inspection information. This is how to build a pergola attached to the house.

Related reading: Best Modern Pergola Designs & Trends

Sizing Your Pergola

A DIY pergola or arbor only has to support its own weight and the weight of whatever you hang from it. This allows you to extend beam and rafter spans. On a larger pergola, however, you don’t want the lumber to appear unsubstantial, so it is important to increase the size of the members appropriately. Move up to 6-by-6 posts and 2-by-8 beams and rafters to keep the pergola looking sturdy. Add intermediate posts and additional beams anytime a beam or rafter span is longer than 12 feet to prevent sagging in the future.

Ledger Board

The ledger board attaches to the house framing and supports the pergola rafters. You can attach the ledger to the roof rafters, but it is better to attach it to the wall framing. Cut the ledger board from 2-by-6 or 2-by-8 lumber. If you’re using anything but pressure-treated lumber, seal the ledger board with a quality wood sealer before you start construction. Insert a piece of Z flashing behind the siding above the ledger location and attach the ledger to the wall studs with two 1/2-inch galvanized lag bolts through the ledger into each stud.

Posts

Layout the posts for your DIY pergola. The posts support a double beam, which supports the rafters. Hang the plumb bob from the end of the ledger so the point is just barely above the patio surface. When it stops swinging, mark the patio under the point. Measure straight out from the mark to the patio edge and mark again. Snap chalk lines between the marks at the house and the patio edge.

Measure back towards the house 8 to 12 inches from the patio edge along the chalk lines and mark. Snap a new chalk line between these marks. Place the posts on this line equidistant from the lines perpendicular to the house. Ensure a square layout by measuring diagonally to the plumb bob marks from the intersecting chalk lines. Both measurements should be the same.

Drill holes into the patio at the post marks with a hammer drill and place lag bolt sleeves into the holes. Attach adjustable post brackets to the patio with 1/2-inch lag bolts screwed into the sleeves. Stand a post in each bracket and temporarily brace them with two pieces of 1-by-4 lumber. Plumb the post with a post level and nail it to the bracket with galvanized 1 1/2-inch bracket nails.

Beams

Attach a mason line to the bottom edge of the ledger at the middle and pull it out to the posts. Attach a line level to the mason line and find the level point on each post and mark it. The double beam should extend beyond the posts. Cut decorative ends on the two pieces and hold them on the posts parallel to the house with the top edges even with the level lines from the ledger. Attach the double beam to the posts with two 1/2-by-7-inch carriage bolts at each end.

Rafters

Space the rafters evenly and no more than 16 inches apart. Cut the outside end to match the decorative ends of the double beam. Attach the rafters to the ledger board with galvanized joist hangers, screws and bracket nails. Use galvanized hurricane ties to attach the rafters to the beam. You can add additional pieces of narrowly spaced 2-by-2, 1-by-3, or lattice across the top of the rafters for additional shade. That’s how to build a pergola attached to the house.

Conclusion

Building a pergola attached to your house takes careful planning and proper steps. Ensure your materials are of good quality; the ledger must be securely connected to the wall framing. Your posts and beams must be sturdy and spaced well for roof support. Always check local building codes before you begin. If done perfectly, the new outdoor shaded area will beautify and enhance your patio or deck with comfort. Put in plants or decorative elements to customize the area to your liking. Keep safe, and enjoy your outdoor haven.

FAQs (Frequently Asked Questions)