How to Build Wooden Steps or Decks
DIY Decks and Steps
10 "Steps" to Build Your Own Steps (or Deck)
Here's how we made a new deck with steps on one side:
1. Measure the Area, and Draw out What You Want to Build
- Graph paper
- Tape measure
- Laser level, if available
- Read all the steps first, then plan things out.
- Do a scale drawing. Graph paper helps.
- Draw parts to scale - can you use standard lengths?
- The ADA specs work for most folks. Remember to allow for swinging doors.
2. Mark out the Area Where You Are Going to Build
(If you are replacing an existing structure, remove it now, and save the parts for patterns.)
- Tape measure
- Crowbar, hacksaw, etc.
- Make it square. Saves time later. (Use a 3,4,5 triangle to find square—see drawing.)
- If you're building indoors or on an existing pad, you mark it with chalk or spray paint. If you're building on dirt, mark it with stakes.
- Set the stakes outside where you plan to build, so the strings cross over the important places like pier blocks or corners. That way you can untie the strings, start digging, and then re-tie them to check your work.
3. Supply Run
Get lumber (footings, supports, and decking), bolts, brackets, deck screws. If needed, also get pier blocks, gravel, concrete bolts, and vapor-barriers. (Railings and brackets, trim and finish can wait until later.
- Square Level
- A counter-boring drill bit, bolt-sized bit and deck screwdriver bits
- Extension cord(s)
- Wheelbarrow or gravel bags
- And maybe get lunch
- Use your drawing to calculate the amounts you need. Get 10% extra.
- You can reuse old lumber in a lot of ways, but make sure anything that touches the ground is rot-proof. Pressure-treated wood lasts longest, but it's toxic. Cedar lasts reasonably long, with less arsenic. Don't use any wood that's already rotting it will spread.
- Use a moisture barrier between the wood and outdoor foundations, and consider drainage for the whole thing.
- Screws are cheaper by the pound. You'll want several matching screwdriver bits.
4. Set Pier Blocks, or Bolt a Footer to Your Existing Foundation
- Tamper (plywood on a pole works fine)
- OR, bolts, bolt-gun, and footer
- For pier blocks or concrete footing, figure out how high the bottom of your block or footing needs to be, and dig 12" to 18" below that. (Should also be to mineral soil below frost level). Fill with gravel, compacting every few inches.
- Set the pier block onto the gravel, or build a form and pour a concrete footing. Line up any slots or brackets to hold the planks in place.
- Level and Drainage: Aim for level. Outdoors, give it a slight outward slope for drainage. An inch in 8 or 10 feet is enough—that's under 1/8 inch per foot. You can set this slope now, or use shims to adjust your supports later. The closer you get now, the better. Add gravel or sand and tamp it to level.
- No foundation: Stairs need lateral support. If you can't bolt them down, or are using loose pier blocks, connect both ends of the staircase with a horizontal tie (on the bottom) and triangular braces. Check older local steps for good and bad examples.
5. Build Support Frames for Deck / Landing and Run Supports for Stairs
- Tape measure
- Adjustable angled "square," if available
- Decks or landings: You are basically building a big, shallow, level box or frame. Use 2"x8" boards, set on edge. Attach them firmly at the ends, and to the wall joist if available: use brackets, bolts, or both. Include a faceplate to attach the step supports if needed. For larger decks, or high landings, add diagonal corner braces.
- Once the main frame is in place (check that it's square!), add supports for the decking. Build in supports every 2 feet, in the opposite direction as you will lay the deck. Attach these securely to the main box with nails or hanging brackets. Cut some 2' bracers to hold the supports in place, and nail or bracket these too.
- Check level frequently: you don't want it to slope in any direction except the slight drainage. You can use small pieces of wood as shims to raise a low corner, or notch it slightly to meet the foundation/pier block on a high corner. Make sure the whole thing is sturdy, even if the shims go missing.
- If you are building a landing or support at the top of stairs, you will need to frame this and a footer before you can fit the stair.
- Stairs and steps: Make all steps the same width and height to prevent accidents
- ADA recommends at least 11" deep for big feet, and not more than 5" high. Remember that the step planks themselves are usually 1-2" thick - adjust your supports so that the finished top of each step will be an equal distance apart, or you may have a dangerously steep bottom step.
- For diagonal stair supports, use 2x12" boards (or logs), to fit the space. Cut the ends to fit flush with the header, and try to notch it where it meets the footer. (You can use a footer across pier blocks, too, as long as it's tied to the other supports. Use a horizontal tie to connect the bottom footer with the top support, if there is any chance that the bottom support can give or slide outward.).
- Prepare blocks or braces to firmly nail/bracket the stair support ends in place, but don't attach them yet.
- Step supports: Steps must be close to level, and evenly spaced. Here are 2 ways to create steps: the notch, and the box (illustrated).
- Notching: Lay your supports in place, then cut level notches for stairs. Be careful to leave enough board to support the weight (250 lbs or much more - any chance of moving a fridge down these stairs?). For longer stairs, use wider wood. (If you are thinking, "I could stand in the middle of a 2"x8" this long, no problem", then get a 2"x12" so there is still 8" left when you are done cutting notches.) This method is great for shorter steps. If your foundation is level, you can bundle and cut multiple boards all at once, creating consistent stairsteps.
- For short steps (total height <12"), you can use a board on its side instead of diagonally, cutting notches parallel to the floor.
- Box/Ladder: Build the staircase like a slanted ladder. Bolt or nail tread supports firmly to the sides, underneath each step. Then attach stair treads atop these supports. Consider adding a notched center support or backing for extra stiffness. Your planks remain intact, the strength of each step depends on the fasteners.
- For railings, create boxes or braces for the railing posts, or bolt them firmly onto the intact side supports in at least 2-3 points per joint. More connection points are stronger, if you can do it without weakening either support.
6. Check Level, Plumb, Rise and Run, Etc.
- Plumbline (rock on a string)
- Check level both directions along the deck, and between supports for each stair tread. Spot-check a few diagonals (for a square or rectangular shape, both diagonals should be the same length). Stand back and look at the overall impression.
Do this now, or it will haunt you later.
7. Install Deck Boards and Stair Treads
Your handy saw/drill/screwdriver, etc.
- For decks and landings: Start at one end (your original square point, maybe) and work toward the other end. Maintain a consistent small gap (1/4" or 1/8") between each board—cut a spacer from a small piece of trim or use a paint-stir-stick. Use your square to make sure you don't end up going askew. You may need to rip the last board to fit, and cut notches around railing supports or stairs.
- If you need more than one length of the deck board to bridge the full distance, have ends meet in the center of supports, and try to alternate the joins instead of lining them all up.
- For stair treads, use a single stair tread board for each step. Make sure it is supported well. (Stair tread is usually clear-vertical-grained wood for indoors, but you can use 2x12's if it's cheaper.)
- Stair treads should also have a "kick-plate" to prevent feet from slipping through. You can install this from behind each stair now, or as a trim piece later. It's easier now.
8. Install Railings
- Bits Saw
- Sandpaper (Special railings and brackets, if needed)
For ADA, the railing should be continuous, 1 1/4" to 1 1/2" in diameter; 1 1/2" inches away from any wall, and able to support 250 lbs without undue stress. (Brackets are generally sized to support these requirements.) It should extend beyond the stairs (12" at the top, one stair tread plus 12" at the bottom) with smooth or rounded ends.
- Mark the desired height (34-38" above the front edge of each stair) on the supports or wall.
- Position the top of the railing at the desired height. Mark the bracket or rail placement. (If screwing into a wall, place brackets at studs or joists.)
- Cut and sand rail (and supports) as needed.
- Screw or bolt brackets in place, and attach railing to supports.
9. Trim, Sand, and Finish
It's time for another shopping run! Is the project "supervisor" giving you all kinds of "helpful" advice? Here's their chance to make the big decisions. A 1/2" by 2" trim board works fine as flush trim, or use extra 2x4"s as a toe rail and trim. Include lattice or whatever. Select a stain and clear coat, deck paint, or other deck finish.
- Finish nails and hammer (or more deck screws and plugs)
- Brushers or rollers
- Gloves and ground cloth if needed (for cleanup)
- Place trim on the exposed ends of the deck boards, and all the way around. Finish with lapped or mitered corners.
- Plug screw-holes if desired, and sand surface to remove splinters.
- Dust off the surface, apply finish according to directions. Wait recommended time between coats.
- If you want a slight safety-tread surface without buying another product, you can sprinkle fine sand onto wet clear-coat and then re-coat after it dries.
10. Clean Up and Celebrate
- Bucket or caddy
- Save some screws and plugs, and finish or paint, in case of future repairs.
- Oil or refinish every few years to extend life.
- Keep leftover wood dry for future projects.
- Last but not least, let the "supervisor" buy you dinner!
A Few Last Words
You will notice that we did not use any glue, 'Nails in a tube,' or other patented goop. The last thing we want in stairs or decking is a rotting support that we can't get to because it has another board glued over a screw or bolt-head.
No project is perfect. We try to build our projects so they can be taken apart again later, to remodel or restore them.
These directions are intended for a simple deck or front stoop. Ask your local building supply (or builders you may know) for any tips on building in your particular location or situation.
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.