Install Subfloor Sheathing

A. Finished-Project Specification

Scope: one completed structural subfloor deck covering the full floor-framing area shown on the approved plan, including all required panel openings, edge support, staggered joints, adhesive bonding, and fastening to the approved schedule.

B. Required Documentation Schedule

Document	Source	Confirmation Required
Subfloor-panel specification	Design professional / manufacturer	Panel type, thickness, span rating, and orientation confirmed
Adhesive product data	Manufacturer	Temperature range, open time, and bead-size requirements confirmed
Fastening schedule	Design professional / manufacturer	Edge and field fastener type, size, and spacing confirmed
Floor-framing inspection	Authority having jurisdiction / general contractor	Joist, blocking, and rim inspection from Project 04 confirmed complete
Floor-opening plan	Design professional / plan set	Location and dimensions of stair, duct, plumbing, and chimney openings confirmed

C. Layout Materials and Consumables

• Subfloor panels: approved product, thickness, and span rating sufficient to cover the full floor area, plus the project's stated waste allowance.
• Construction adhesive: approved product in sufficient quantity for the full deck area at the specified bead size.
• Fasteners: approved type, length, and quantity for the full edge and field schedule.
• Documentation: one subfloor installation record per floor area.

D. Acceptance Standards

Check	Standard
Panel edge support	Every panel edge bears fully on a joist, rim board, or approved blocking; no edge spans unsupported between framing members
Joint staggering	End joints between adjacent courses are offset by the distance stated in the approved panel layout; no continuous unbroken joint line across multiple courses
Panel gaps	Perimeter and end-joint gaps match the panel manufacturer's stated requirement; no gap is fully closed or forced tight
Fastener installation	Fasteners match the approved edge and field schedule for type, size, and spacing; seated flush without overdriving or missing framing
Adhesive bond	Adhesive bead matches the manufacturer's size and placement requirement and the panel was seated before the adhesive skinned
Deck flatness	No high or low joint exceeds the tolerance stated on the approved specification, checked with a straightedge

E. Framing Verification and Course Planning (Steps 1–7)

1. Review the subfloor-panel type, thickness, span rating, orientation, edge profile, adhesive, fastening schedule, panel-gap, and diaphragm requirements. Record each value on the subfloor installation record before staging panels.
2. Confirm joist spacing, blocking, rim restraint, openings, and framing inspection are complete. Verify the Project 04 inspection sign-off before placing any panel.
3. Clean joist tops of mud, ice, standing water, debris, protruding fasteners, and incompatible coatings. Sweep and inspect the full joist run before staging panels over it.
4. Verify joist crowns, elevations, and alignment before panels conceal the framing. Sight the joist tops with a straightedge and correct any deviation authorized under Project 04's acceptance standards before proceeding.
5. Stage panels flat, dry, supported, and close enough for controlled handling. Keep staged panels off the ground on dunnage and covered from weather until placed.
6. Establish the first panel reference line perpendicular to the joists unless the approved system requires another orientation. Strike the reference line with the chalk line from the building's primary reference corner.
7. Plan full-panel placement, staggered end joints, supported edges, openings, and final-row cuts. Sketch the course layout on the installation record before cutting the first panel.

F. First Panel Placement and Adhesive Bonding (Steps 8–14)

1. Confirm that every panel edge will bear on framing or approved edge support. Check the planned course layout from Step 7 against the joist and blocking layout before cutting.
2. Measure and mark the first panel from a defined factory edge. Use the same factory edge as the reference for every subsequent measurement on that panel.
3. Cut panels using supported work methods and protect the finished face and tongue-and-groove edges. Support the panel fully during cutting to prevent breakout at the cut edge.
4. Dry-fit the first panel and verify square to the floor framing. Check the panel against the framing square before applying adhesive.
5. Apply only the approved construction adhesive within its temperature, open-time, and bead requirements. Apply the bead to the joist tops the panel will bear on, following the manufacturer's placement pattern.
6. Place the panel before the adhesive skins and seat its edges without damaging the tongue. Use a panel-edge pry bar or clamps to close tongue-and-groove joints without forcing the required gap closed.
7. Maintain the required perimeter and end-joint gaps. Use gap spacers or the manufacturer's stated gap method at every panel end and edge.

G. Fastening, Subsequent Courses, and Openings (Steps 15–19)

1. Fasten the first panel using the approved edge and field schedule. Drive fasteners in the sequence and spacing recorded on the installation record.
2. Install subsequent panels in staggered courses and maintain joint support. Confirm each new panel's end joint is offset from the adjacent course by the approved distance before fastening.
3. Use approved panel-edge tools or blocking to close tongue-and-groove joints without over-tightening required gaps. Recheck the gap after each panel is seated.
4. Cut and frame openings for stairs, ducts, plumbing, chimneys, and access only from approved dimensions. Mark each opening from the plan before cutting and guard it immediately after the cut is made.
5. Do not leave unsupported partial panels or narrow strips outside the approved layout. Adjust the course layout so every final-row cut still lands on supported framing.

H. Inspection, Correction, and Closeout (Steps 20–24)

1. Inspect fastener type, spacing, seating, missed framing, overdriving, and panel damage during installation. Check each course as it is completed rather than waiting until the full deck is installed.
2. Check the completed surface for high joints, low areas, squeaks, delamination, damage, and unsafe openings. Walk the full deck and check suspect joints with a straightedge.
3. Correct failed fasteners, unsupported edges, damaged panels, adhesive gaps, and layout errors before wall framing. Use the approved repair method for the specific defect found; do not conceal a defect under later framing.
4. Cover or guard all floor openings. Confirm every opening guard is complete and secure before leaving the area.
5. Record panel product, orientation, adhesive, fastening, gaps, repairs, and inspection results. Complete the subfloor installation record before wall layout begins.