How to Build a Multi-Level Deck

  • 70 hours
  • Intermediate
  • 500-1,000
What You'll Need
Lumber
Screwdriver
Post hole digger
Screws
Saw
Varnish
Paint Brush
Joist Hanger
Level
Drill and bits
Hammer

A multi-level deck can provide hours of entertainment and many serene moments of Zen. Use it to focus on details of the patio or another garden feature you’re especially proud of. It's not a project for the faint of heart, so if you’re not naturally blessed with carpentry know-how, a friend or family member with deck building experience, or handy skills combined with the drive to accept this challenge, do your research and proceed with caution. Don’t be deterred if you don’t have these skills, as long as you have patience and fortitude to begin. (But we do encourage you to make friends with the staff at your local home improvement store.)

Step 1 - Do Your Homework

Check for city or county regulations regarding a deck installation to verify code requirements for your area. These regulations will ultimately dictate your decisions to either add on or start from scratch, height and spacing of railings, footing size, joist and beam spans, and may even describe the type of acceptable hardware and lumber.

In addition to city regulations, check with your HOA to get the proper approvals before work begins. They can quickly put the kibosh on a project deemed not in keeping with the look of the neighborhood, wasting time, money, materials, and effort. And you could be in for a fight if your HOA won’t don’t back down.

A brand-new build may also need some excavation to create a level surface. Before any digging commences, call 811 to check for any underground lines on your property that could suffer damage from your project.

backyard with multi layer deck

Step 2 - Decide on Design and Layout

Adding a level to an existing deck is an easier way to create a multi-level design, especially if you can salvage any of the framework and decking materials that are still in good condition, and in keeping with your planned footprint. If you aren’t so lucky, factor in demolition and rubbish removal into the budget so you can start with a clean slate.

There was a time when redwood and cedar were the only choices when building a new deck. These days, the wide variety of decking materials available allow you more options so you can choose based on factors like your environment, your budget, and your own preferences. Pressure treated wood is a less expensive option from cedar and redwood, but will require regular application of sealer or stain at least every other year to keep it looking good. Vinyl and composite decking require less maintenance, but are at least as expensive as natural redwood.

Once you’ve decided on final design and type of materials, procure your materials and store it appropriately until construction begins.

Step 3 - Install the Ledger Boards

Install a ledger board to provide strength to the framing and the deck. Remove any siding skirting the bottom of your house to the height of the deck. Fit enough ledger boards to cover the area exposed by the removed siding. If your house has a brick or stone veneer, you won’t be able to attach it to the house. Instead, build a free-standing frame to support the new deck.

Ledger boards should be placed at the same height up the side of the wall as the supporting deck footers. A laser level will ensure your deck is completely level and prevent you from accidentally designing a ramp instead of a deck. Of course, you don’t need one of these fancy tools to accomplish this task. The same result can be achieved by securely taping a spirit level to a very long board to work out the positions and heights of the footers.

Secure the boards temporarily with framing nails every two feet. Don’t secure lag screws just yet so they don’t get in the way when you install joists later.

Install flashing around the perimeter where ledger board meets the house. Then reattach siding to the house, allowing for the height of the decking material.

Step 4 - Determine Joist Spacing

This will vary depending on the type and size of lumber used. Mark the locations of joists on ledger board. Once these have been marked, properly secure the ledger board with lag screws, being sure to comply with your building authority regarding spacing and type of structural fastener particular to your situation.

Step 5 - Set up Footings

Use a post hole digger to dig the post holes before installing the deck footings. These holes will need to be deeper than the frost line in your local area, so ensure that you know where this is, and get guidance from your local authority on how deep the holes should be placed. Stand the posts in the holes and pour concrete in each hole, allowing them to set and cure for 48 hours.

Tip: Consult your building authority prior to pouring concrete. They may require an inspector come out and check the progress of your project before footings are completed.

hand laying boards on a deck

Step 6 - Add Framework and Decking

A multi-level deck adds complexity to a single level build since you must determine how the levels will be supported and attached to each other. Frame the levels one at a time to give you a reference point as you’re building. If your design includes a level not attached to the ledger board, additional bracing is required to achieve a stable design.

Attach 2” x 10’ joists at the pre-determined locations you figured out in Step 4 along the ledger board. Once joists are in place, lay decking material across the joists, leaving a 1/8” gap between boards. If lumber is wet, boards can be laid butted up against each other since gaps will open up between them as they dry.

Step 7 - Protect Your Investment

If you chose vinyl decking, you chose a color ready to install, but wooden decking will need to be protected after installation. Deck stains come in a variety of colors to suit your desires. You’ve accomplished a great deal, so after you’ve taken a break to admire your work, protect it with a stain and moisture sealant that will keep it beautiful for many years to come.