Your Roof = Your First Line of Defense #
Roof panels protect your building from weather and temperature shifts, and poor installation can lead to long-term problems. This section outlines how to install your roof insulation, metal panels, and ridge cap with exact spacing, overlap, and sealant placement.
⚠️ Working at height is dangerous. Always follow OSHA fall protection rules. Never walk on unsecured panels.
Tools and Safety Equipment #
- OSHA-compliant fall restraint (lifelines, rails, or nets)
- Vice grips for panel securing
- Safety harnesses and non-slip footwear
- Chalk line, screw gun, 1/4” drill bits
- Sealant tape and closure strips
Insulation First #
- Cut insulation eave-to-eave plus 4 feet extra (2′ per side)
- Apply double-sided tape to the top of both eave trims
- Stretch insulation tight across roof
- Trim flush to eave trims
- Fold excess vapor barrier for weather protection
Only install insulation over areas that will be covered by panels that same day.
🖼️ Diagram: Roof Insulation Layout #
Fig. 53 – Run insulation eave to eave, tension flat, and fold ends.
Roof Panel Installation: Start at the Edge #
- Pre-drill lap screw holes along the high rib, every 20″
- Align the first roof panel over the insulation, allowing 2″–3″ overhang past eave
- Clamp in place with vice grips
- Install inside closure strip over insulation at eave
- Fasten panel to eave strut using #12 x 1-1/4” screws (every 6″)
- Fasten to purlins every 12″
🖼️ Diagram: First Roof Panel with Closure Strip #
Overlapping Panels #
- Apply sealant tape along the top of the high rib on installed panel
- Lay next panel over it, matching profile
- Stitch panels together with #12 x 7/8” screws (every 20″)
- Clamp, align, and secure panel to structure
- Repeat insulation + panel process across roof
Do not cover sealant tape with stitch screws—this can create leak points.
Multi-Run Roofs & Skylight Considerations #
- Backlapping (overlapping top panel row over bottom) may be needed to match full width
- Always cut panels so factory edge faces overlap
- For skylights, follow specific instructions on lapping over adjacent panels and sealing fully
🖼️ Diagram: Overlap with Sealant Tape #
Ridge Cap Installation #
- Stretch chalk line across roof peak
- Place sealant tape on both roof panel peaks, just below the lap line
- Position ridge cap and align to chalk line
- Fasten ridge cap using #12 x 1-1/4” screws every 6″ into peak purlin
- Overlap each ridge cap section by 3″
- Caulk seams and remove any temporary screws from panel tops
Sweep away metal shavings to prevent rust at the screw points.
Fig. 67 – Ridge cap overlaps, sealant lines, and fastener position.
Final Safety Notes #
- Never walk on translucent panels (skylights)
- Use only approved scaffolding and walk boards
- If using temporary screws for walking access, remove before final closure
FAQ #
How do I know my roof panels are aligned correctly?
Use a chalk line and confirm rib-to-rib spacing with each install. Don’t rely on visual alone.
Do I need to pre-drill for every screw?
No, only for lap screws. Structure screws can be driven directly through panel and into purlins.
What’s the most common mistake during roofing?
Skipping or misplacing sealant tape. That leads to long-term leaks.
📘 Download Our Roofing Install Guide #
From closures to ridge caps—get the full layout and sealing instructions.
👉 Download our free eBook: From Dirt to Done
