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Safety Cue
Task-specific safety guidance for ordinary work hazards.
Project 08
Build Deck Stairs
Calculate a uniform rise and run, lay out and cut stair stringers, install them against a stable platform and landing, hang treads, and inspect the finished stair for the geometry and support every later guard and handrail chapter depends on.
Field Cue System
These cues appear at the point of work. They identify safety, code, manufacturer, and measurement issues before they become rework or hazards.
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Critical Safety Cue
Serious injury, fire, or major damage is possible.
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Field Safety Cue
Practical work-area safety: lighting, cords, footing, and housekeeping.
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Code Alert
Local requirements vary. Verify permit, inspection, and jurisdictional rules.
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Manufacturer Cue
Follow product-specific instructions for tools, materials, and equipment.
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Measurement Cue
Clearance, layout, spacing, and reference-point guidance.
Job Overview
This project qualifies you to calculate stair geometry from a measured total rise, lay out and cut approved stringers, install those stringers against an accepted platform and a stable lower landing, hang risers and treads, and inspect the finished stair before it carries foot traffic. The finished work product is one complete exterior stair section: uniform risers and treads, securely connected stringers, and a documented inspection record.
You will measure total rise from the finished deck surface to the finished lower landing, calculate the number of uniform risers the approved design allows, lay out and cut a template stringer, verify it against the approved throat depth and notch limits, use it to produce the remaining stringers, install and connect every stringer, hang treads and risers, and inspect the completed stair for uniformity, attachment, and safe use before it is opened.
This project assumes Project 06 (deck framing) and Project 07 (decking) are complete and inspected, and it builds the stair that Project 09 will fit with guards and a graspable handrail. No stair built under this project is opened to use until barricading is removed under the acceptance standards in this chapter, and no guard or handrail work in Project 09 depends on a stair that has not passed the checks in this chapter first.
Skills You Will Demonstrate
- OS-043 — Calculate stair rise and run from a measured total rise and the approved design geometry.
- OS-044 — Lay out stair stringers using a framing square, stair gauges, and an approved template method.
- OS-045 — Cut stringers without overcutting inside corners, preserving the required throat depth and notch limits.
- OS-046 — Install stringers with approved upper and lower connections, spacing, and lateral restraint.
- OS-047 — Install risers and treads with approved overhang, spacing, support, and fasteners.
- OS-048 — Inspect stair safety, including uniformity, attachment, landing condition, and slip and drainage control.
Where This Skill Fits
This project depends on the accepted deck frame and decking surface from Project 06 and Project 07, and it depends on the site drainage and grade information recorded back in Project 01. The stair geometry, stringer attachment, and landing condition documented here are the load path and reference that Project 09 uses to install guards, handrail, and stair-transition components. A stair that has not passed the acceptance standards and inspection in this chapter cannot be handed to Project 09 for guard and handrail work.
The discipline built in this chapter — calculating uniform rise and run before any cut is made, verifying a template stringer before committing the remaining stock, and treating a stair as unsafe to use until it is fully inspected — is the same discipline that governs stair and access work throughout the rest of this book, including the Chapter 20 capstone.
Scope and Intended Use
This project covers:
- measuring total rise from the finished deck surface to the finished lower landing
- calculating a uniform number of risers and the corresponding tread run from the approved design
- laying out, cutting, and verifying a template stringer
- producing and installing the remaining stringers from the verified template
- installing approved upper and lower stringer connections, blocking, and lateral restraint
- installing risers and treads with approved overhang, spacing, support, and fasteners
- inspecting the completed stair for uniformity, attachment, and safe access before it is opened
This project does not authorize the learner to:
- invent riser height, tread run, stringer notch depth, stair width, or landing dimensions that are not supplied by the approved design, adopted code, or engineering documents
- cut stringers before the total rise has been measured from the actual finished platform and landing elevations
- open the stair to regular use before guards, handrails, and the checks required by Project 09 are complete where the approved design requires them
- proceed to Project 09 with a stair that has not passed the acceptance standards and inspection in this chapter
Any riser, tread, or stringer condition that cannot be confirmed as uniform, or any stringer connection that cannot be verified against the approved detail, must be resolved before this project is declared complete.
Reference Conventions
Establish these references before any stringer is laid out, and do not change them mid-project.
| Term | Definition |
|---|---|
| Total rise | The vertical distance from the finished lower landing to the finished deck surface, measured on site before layout begins |
| Riser height | The vertical height of one step, calculated by dividing total rise by the approved number of uniform risers |
| Tread run | The horizontal depth of one step, set by the approved design and confirmed against nosing and finish thickness |
| Stringer | The cut, notched framing member that supports risers and treads and carries the stair's load to the platform and landing |
| Throat depth | The remaining solid width of a stringer after the rise-and-run notch is cut; a minimum required to keep the stringer from failing at the notch |
| Landing | The stable surface at the top or bottom of a stair where a full stride is taken; must be confirmed level, stable, and at the correct elevation before layout |
| Nosing | The projection of a tread beyond the riser face below it, included in tread-run calculations where the approved design specifies it |
Stair Design Record
Before cutting any stringer, record the approved stair geometry directly on the stair layout worksheet:
Total rise measured: ______ Number of risers: ______ Riser height: ______ Tread run: ______
Stair width: ____________ Stringer count and spacing: ____________ Landing type: ____________
Prerequisites
- The deck frame from Project 06 and the decking surface from Project 07 accepted and at final elevation
- The lower landing established, stable, and at its finished elevation, whether concrete, pavers, or another approved surface
- The approved stair design, including total rise range, riser and tread standard, stair width, stringer count, and connection details
- Straight, undamaged, correctly graded and treated stringer, riser, and tread stock staged and ready for layout
- A blank stair layout worksheet and access to the framing square, stair gauges, and cutting station
Common Field Fundamentals
Every stair in this book, from a short deck step to the Chapter 20 capstone, follows the same sequence taught here: measure total rise, calculate uniform geometry, lay out and verify a template, cut and install the remaining stringers, hang treads, and inspect before use. Learning that sequence on this stair means every later stair in this book starts from a method you already trust.
Rise measurementTotal rise confirmed from actual finished landing and deck elevations
Geometry calculationUniform riser height and tread run calculated and recorded
Template stringerFirst stringer laid out, cut, and test-fit before others are cut
Stringer installationApproved upper and lower connections, spacing, lateral restraint
Tread and riser installApproved overhang, spacing, support, and fasteners
Safety inspectionUniformity, attachment, landing, and slip and drainage checked before use
Uniform Rise and Run
A stair with even one riser out of tolerance from the rest of the run is a fall hazard, because a foot expects the same step height every time. Every riser is calculated from the same measured total rise and the same approved number of risers, and every stringer is laid out from the same square settings, so the finished run is uniform top to bottom.
OS-043 – OS-048
Exterior Stair Construction Qualification
Build Deck Stairs
A. Finished-Project Specification
Deliverable: one exterior stair section with uniform risers and treads, stringers cut to the approved geometry, secure upper and lower connections, hung risers and treads, and a completed stair inspection record.
B. Assessed Stair Build Schedule (Component Schedule)
| Component | Quantity | Format | Standard | Preparation / Purpose |
|---|---|---|---|---|
| Total rise record | 1 | Worksheet entry | Measured on site from finished deck to finished landing | Establishes the baseline for all geometry calculations |
| Riser and tread calculation | 1 | Worksheet entry | Uniform riser height and tread run per approved design | Sets the layout dimensions for every stringer |
| Template stringer | 1 | Cut and test-fit | Verified against throat depth, notch limits, and total rise before use as a pattern | Confirms the layout before remaining stringers are cut |
| Stringer set | Per design | Cut, treated, installed | Uniform spacing, approved upper and lower connections, lateral restraint | Carries the stair's load to the platform and landing |
| Risers and treads | Per design | Installed | Approved overhang, spacing, support, and fasteners | Provides the finished walking surface |
| Stair inspection record | 1 | Signed worksheet | Uniformity, attachment, landing, and slip and drainage confirmed | Authorizes use of the stair and handoff to Project 09 |
C. Material and Resource Takeoff
- Stringer stock: straight, correctly graded and treated stock sufficient for the approved stringer count, with allowance for one rejected test cut.
- Risers and treads: exterior-rated material matched to the approved tread run, stair width, and overhang detail.
- Connectors and fasteners: listed stringer connectors, treads fasteners, and hardware matched to the lumber treatment for corrosion compatibility.
- Documentation: the stair layout worksheet, total rise and geometry calculations, and photographs required for the inspection record.
D. Acceptance Standards
| Check | Standard |
|---|---|
| Total rise and geometry | Total rise measured on site; riser height and tread run calculated to the approved design and confirmed uniform |
| Template stringer | Test-fit against platform and landing and accepted before remaining stringers are cut |
| Stringer cuts | No inside-corner overcuts; throat depth and notch limits within the approved detail on every stringer |
| Stringer installation | Approved upper and lower connections, uniform spacing, and lateral restraint installed and verified |
| Treads and risers | Installed with approved overhang, spacing, support, and fasteners; every riser and tread measured for uniformity |
| Landing and drainage | Landing confirmed stable and at the correct elevation; stair surfaces checked for slip hazard and drainage |
E. Preparation — Rise Measurement and Geometry Calculation
- Review the approved design. Confirm total rise range, riser and tread standard, stair width, stringer design, attachment details, footings, and any guard or handrail requirements this stair must accommodate later.
- Confirm the platform and lower landing are stable and at final elevations. Do not begin layout against a landing that has not reached its finished, accepted condition.
- Measure total rise from the finished lower landing to the finished deck surface. Take the measurement at the actual stair location, not from a plan dimension alone.
- Calculate the approved number of uniform risers. Use the total rise and the approved design's riser-height range to determine the count.
- Determine finished riser height and tread run from the approved design. Confirm both values fall within the applicable requirement.
- Include tread thickness, decking thickness, nosing, and landing finish in calculations. Adjust the layout dimensions so the first and last riser height match the rest of the run once finish materials are accounted for.
F. Stringer Layout and Template Verification
- Prepare a full-scale stringer layout or approved template. Select straight, correctly graded and treated stock for the first stringer.
- Mark rise and run using a framing square and stair gauges. Set the gauges once to the calculated riser height and tread run and leave them clamped for the remainder of the layout.
- Mark top and bottom cuts. Account for the platform and landing connection details in the top and bottom cut lines.
- Verify remaining throat depth and notch limits. Confirm the layout leaves the required solid width at every notch before any cut is made.
- Cut the first stringer without overcutting inside corners. Stop the circular saw cut short of the inside corner on every notch.
- Finish inside cuts with a handsaw or approved tool. Complete each inside corner precisely to the layout line without extending past it.
- Test-fit the first stringer. Set it in position against the platform and landing and confirm rise, run, and bearing match the calculated geometry.
- Use the accepted first stringer as a template only after verification. Do not trace or cut additional stringers from a stringer that has not been test-fit and accepted.
G. Remaining Stringers, Connections, and Bracing
- Cut remaining stringers. Trace each from the accepted template and repeat the inside-corner finishing method on every notch.
- Treat all field cuts in pressure-treated material. Apply the specified preservative to every cut end and notch face before installation.
- Install approved upper and lower stringer connections. Use the listed connector and fastener schedule specified for the platform and landing details.
- Maintain stringer spacing and lateral restraint. Set every stringer to the approved spacing and install the specified restraint or blocking.
- Install required blocking. Add blocking between stringers where the approved detail calls for it, before treads are installed.
H. Risers, Treads, and Coordination with Guards
- Install risers where specified. Fasten each riser to the stringer layout line, keeping the top edge consistent across the run.
- Install treads with approved overhang, spacing, support, and fasteners. Confirm each tread sits level and fully supported before fastening.
- Install or coordinate landings, guards, and handrails. Confirm the stair location and geometry match what Project 09 will need for guard-post and handrail placement, without installing guard or handrail components under this project.
- Measure every finished rise and tread. Record each measurement on the worksheet and confirm the run is uniform top to bottom.
I. Recheck, Barricade, and Closeout Procedure
- Inspect uniformity, attachment, stringer cuts, tread support, landing, slip, drainage, and movement. Classify any gap as a geometry error, a connection deficiency, or a landing condition before correcting it.
- Barricade stairs until all safety components and inspections are complete. Do not open the stair to regular use until this chapter's acceptance standards, and any guard or handrail requirement from Project 09, are satisfied.
Common Inspection Review
Inspect the completed stair using the same checks regardless of stair width, riser count, or landing type.
- Geometry check: confirm every riser height and tread run is uniform and matches the calculated and approved values.
- Stringer check: confirm no inside-corner overcuts, throat depth within the approved detail, and every connection installed to the specified schedule.
- Attachment check: confirm upper and lower stringer connections, spacing, and lateral restraint are installed and secure.
- Tread and riser check: confirm approved overhang, spacing, support, and fasteners on every tread and riser.
- Landing and drainage check: confirm the landing is stable and at the correct elevation, and the stair surface sheds water without a slip hazard.
Complete the Stair Inspection Worksheet in the Inspection Checklist section below before opening the stair to use or beginning Project 09.
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Failure Points and Troubleshooting
Cleanup
This project ends with the stair barricaded and its records compiled, not with the stair opened for casual use.
- Leave barricades in place until guard, handrail, and any remaining Project 09 requirements are complete
- Photograph the completed stair, connections, and landing for the inspection record before covering or enclosing any component
- Store leftover stringer, riser, and tread stock and label it for reuse or reference elsewhere in the book
- Label and file the completed stair layout worksheet, geometry calculations, and photographs together
- Return the signed stair inspection record to the project records for reference throughout the rest of this book
Field Terms
- Total Rise
- The vertical distance from the finished lower landing to the finished deck surface.
- Riser Height
- The vertical height of one step.
- Tread Run
- The horizontal depth of one step.
- Stringer
- The cut, notched framing member that supports risers and treads and carries the stair's load.
- Throat Depth
- The remaining solid width of a stringer after the rise-and-run notch is cut.
- Landing
- The stable surface at the top or bottom of a stair where a full stride is taken.
- Nosing
- The projection of a tread beyond the riser face below it.
- Template Stringer
- The first stringer, laid out, cut, and test-fit before being used as the pattern for remaining stringers.
- Lateral Restraint
- The bracing or connection that keeps stringers from shifting sideways under load.
- Stair Inspection Record
- The document confirming geometry, attachment, landing, and slip and drainage conditions before the stair is opened to use.
Skill Check
- Why must total rise be measured on site rather than taken from a plan dimension alone?
- What happens to a stair's safety if even one riser height is out of uniform with the rest of the run?
- Why must the first stringer be test-fit and accepted before it is used as a template for the rest?
- Why is finishing an inside stringer corner with a handsaw required instead of extending the circular saw cut?
- What is throat depth, and why does a stringer notch have a minimum limit for it?
- Why must the landing be confirmed stable and at its final elevation before stringer layout begins?
- What must be true of a stringer's upper and lower connections before treads are considered acceptable?
- Why must a completed stair remain barricaded until guard and handrail work in Project 09 is finished, where the design requires it?
- What are three possible causes of an unlevel or unsupported tread, and how does the learner confirm which one occurred?
- Why does this chapter require every finished riser and tread to be individually measured before sign-off?
Competency Rubric
| Competency | Independent Pass Standard | Not Demonstrated | With Assistance | Independently |
|---|---|---|---|---|
| OS-043 | Calculates uniform riser height and tread run from an on-site total-rise measurement and the approved design | |||
| OS-044 | Lays out stair stringers using a framing square, stair gauges, and a verified template method | |||
| OS-045 | Cuts stringers within throat-depth and notch limits without overcutting inside corners | |||
| OS-046 | Installs stringers with approved upper and lower connections, spacing, and lateral restraint | |||
| OS-047 | Installs risers and treads with approved overhang, spacing, support, and fasteners | |||
| OS-048 | Inspects the completed stair for uniformity, attachment, landing condition, and slip and drainage before use |
Mark one column per competency. Only Demonstrated Independently awards the competency; Demonstrated with Assistance authorizes additional supervised practice but does not complete the requirement.
Inspection Checklist — Stair Inspection Worksheet
| Item | Standard | Recorded Finding | Confirmed (Y/N) | Correction (if any) |
|---|---|---|---|---|
| Total rise and geometry | Measured on site; riser height and tread run uniform and to approved design | |||
| Template stringer | Test-fit and accepted before remaining stringers cut | |||
| Stringer cuts | No inside-corner overcuts; throat depth within approved limits | |||
| Stringer connections | Approved upper and lower connections, spacing, lateral restraint installed | |||
| Treads and risers | Approved overhang, spacing, support, and fasteners; uniform across run | |||
| Landing and drainage | Stable, correct elevation, sheds water, no slip hazard |
Total rise: ____________ Riser count / height: ____________ Tread run: ____________
Stair declared ready for use / for Project 09: ______ (Pass/Fail) Date: ____________ Builder name: ____________
Performance Check
With all six worksheet items recorded, review the completed stair against the Acceptance Standards table and confirm total rise was measured on site and riser height and tread run are uniform and correctly calculated, the template stringer was test-fit and accepted before remaining stringers were cut, no stringer shows an inside-corner overcut and every throat depth meets the approved limit, every stringer connection matches the approved schedule with spacing and lateral restraint installed, every tread and riser is installed to the approved overhang, spacing, support, and fasteners, and the landing is stable, correctly elevated, and free of slip hazards. Complete the Stair Inspection Worksheet and correct any incomplete item before removing barricades or beginning Project 09. If an item is incomplete, identify whether the gap is a geometry error, a connection deficiency, a tread or riser support issue, or a landing condition before rechecking it.
Project Closeout
You have completed the eighth project in the outdoor structures sequence: building deck stairs. This project required you to calculate stair rise and run (OS-043), lay out stair stringers (OS-044), cut stringers without overcutting inside corners (OS-045), install stringers with approved connections (OS-046), install treads and risers (OS-047), and inspect stair safety (OS-048).
You now have a complete, inspected exterior stair with uniform geometry, secure stringer connections, and a documented inspection record. That stair, still barricaded, carries directly into the next project: fitting it with the guards and graspable handrail every open stair in this book requires before it can be used.
Store your stair layout worksheet and inspection record with the project records. You will reference the total rise, riser and tread geometry, and stringer connections recorded here throughout Project 09 and the rest of this book.