Build Staircase
The staircase connects your living space to your new attic room. Quality construction ensures decades of safe, comfortable use and adds value to your home.
Why Quality Stair Construction Matters
Your attic staircase will be used thousands of times over its lifetime - every trip up and down relies on solid construction. Stairs with uneven risers cause trips, wobbly handrails fail to prevent falls, and inadequate structural support can lead to sagging or failure. Building code requirements exist because stairs are a leading cause of home injuries. Taking time to build stairs correctly ensures your family's safety and creates a feature that enhances your home's value rather than detracting from it.
Tools & Materials You'll Need
Step-by-Step Guide
Frame the Stairwell Opening
Create the floor opening that stairs will pass through:
Structural Requirements:
- * Opening typically 10-14 feet long by 36-42 inches wide
- * Double headers at both ends of opening
- * Double trimmers along sides
- * Joist hangers at all connections
- * Engineer approval if cutting more than 2 joists
- Mark opening on ceiling below, accounting for headroom line
- Support joists with temporary walls before cutting
- Cut joists cleanly at header locations
- Install double headers with joist hangers
- Install double trimmers and secure cut joists
- Remove temporary supports once framing is complete
Calculate Rise and Run
Precise calculations ensure uniform, code-compliant steps:
Calculation Process:
- Measure total rise: Floor to floor including subfloor = e.g., 118"
- Divide by ideal riser: 118" / 7.5" = 15.7 risers
- Round to whole number: 16 risers
- Calculate exact riser: 118" / 16 = 7.375" per riser
- Treads = risers - 1: 15 treads at 10-11" depth
- Total run: 15 treads x 10.5" = 157.5" (about 13 feet)
Code Critical: Maximum riser height is 7.75 inches. All risers must be within 3/8 inch of each other. Uneven risers cause trips and fail inspection.
Lay Out and Cut Stringers
Stringers are the backbone of your stairs - cut them precisely:
- Select straight 2x12 boards, minimum 14 feet long
- Set stair gauges on framing square: rise on tongue, run on blade
- Starting at one end, mark first step keeping gauges tight to board edge
- Continue marking all steps, checking count matches calculations
- Mark bottom cut: subtract tread thickness from first riser
- Mark top cut to fit against header
- Cut with circular saw, finish corners with jigsaw
- Use first stringer as template for remaining two
Pro Tip: Cut about 1/16" inside your lines. You can always sand down, but you can't add material back. Test fit before cutting others.
Install Stringers
Secure stringers for rock-solid stair support:
At the Top:
- * Metal stringer hangers are strongest
- * Or nail blocking behind header
- * Screws through stringer into header
- * Top tread flush with attic floor
At the Bottom:
- * Install 2x4 kickplate on floor
- * Secure kickplate with concrete anchors
- * Attach stringers to kickplate
- * First riser height = others minus tread thickness
- *Space stringers: outside stringers at edges, center stringer in middle
- *Check level across all treads before final fastening
- *Use construction adhesive plus screws for maximum strength
Install Risers and Treads
Install risers first, then treads for cleanest appearance:
- Cut risers from 1x8 material to width of stairs
- Apply construction adhesive to stringer cuts
- Install risers with finish nails or screws from back
- Cut treads with 1-inch nosing overhang at front
- Install treads with adhesive and screws into stringers
- Countersink screws and fill with wood filler
- Check each tread for level and solid feel
Tread Options: Pre-made oak treads look professional but cost more ($40-80 each). Pine treads can be carpeted or painted for budget projects.
Install Handrails and Balusters
Handrails are required safety features with specific code requirements:
Code Requirements:
- * Handrail height: 34-38 inches above tread nosing
- * Continuous rail for full stair length
- * Graspable profile: 1.25-2 inch diameter
- * Balusters maximum 4 inches apart (child safety)
- * Handrail required on at least one side
- * Both sides required if stairs 44 inches or wider
- Install newel posts at top, bottom, and any turns
- Secure newel posts with bolts - they take significant load
- Mark handrail angle using stair pitch
- Cut and install handrail sections
- Install balusters at maximum 4-inch spacing
- Test handrail for solid feel - no wobble allowed
Pro Tips
- ✓Build a story pole - a board marked with exact riser heights - to verify consistency
- ✓Use a circular saw guide or track for straight stringer cuts
- ✓Apply finish to treads before installation if using clear finish
- ✓Consider adding LED strip lighting under treads for safety and ambiance
- ✓Install temporary rails immediately - don't leave stairs unprotected during construction
Frequently Asked Questions
How much does it cost to build stairs to an attic?▼
Building attic stairs typically costs $3,000-8,000 for professional installation, including materials and labor. DIY costs range from $500-1,500 for materials only. Factors affecting cost include stair configuration, materials (pine vs oak), and complexity of floor opening framing.
What size lumber do I need for stair stringers?▼
Stair stringers should be cut from 2x12 lumber for residential stairs. This provides adequate depth after cutting the step pattern. Use straight, clear boards without large knots in the critical areas. Pressure-treated lumber is not required for interior stairs.
How do I calculate stair rise and run?▼
Divide total rise (floor-to-floor height) by ideal riser height (7-7.5 inches) to get number of risers. Round to nearest whole number. Divide total rise by number of risers for exact riser height. Tread depth should be 10-11 inches. All risers must be within 3/8 inch of each other.
What are the handrail requirements for residential stairs?▼
Handrails must be 34-38 inches above the stair nosing, continuous for the full length of stairs, and graspable with 1.25-2 inch diameter. Handrails are required on at least one side; both sides if the stairway is 44 inches or wider. Balusters must be spaced no more than 4 inches apart.