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Safety Cue
Task-specific safety guidance for ordinary work hazards.
Chapter 4
Install Ice-and-Water Shield at Eaves and Valleys
Install self-adhered ice-and-water membrane at required eaves, valleys, and vulnerable transitions on a deck that has already received required eave drip edge, achieving the manufacturer-controlled coverage, laps, and adhesion before synthetic underlayment and shingles begin.
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, fall, or major damage is possible.
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Field Safety Cue
Practical work-area safety: footing, weather, housekeeping, and access.
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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 materials, fastening schedules, and equipment.
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Measurement Cue
Slope, span, clearance, and reference-point guidance.
Job Overview
This chapter qualifies you to install self-adhered ice-and-water shield membrane at required eaves, valleys, and vulnerable transitions on a roof deck that has already passed the Chapter 1 readiness inspection and received the eave drip edge required by Chapter 3. The finished work product is a fully adhered membrane system covering the required interior distance at eaves, running the full length of every valley from low point to high point, integrated at corners and plane changes without fishmouths or reverse laps, and documented with product, lot, weather, and inspection records.
You will confirm the substrate is clean and dry, apply primer only where the manufacturer requires it, plan membrane widths and courses so the required coverage is achieved without an unsupported seam, install the membrane from a straight eave reference and from the low point of each valley toward the high point, treat every corner and transition without trapped air or reverse laps, seal approved penetrations and cuts, and inspect the completed membrane for wrinkles, voids, and adhesion failure before it is covered by synthetic underlayment.
This chapter follows Chapter 3 and precedes Chapter 5. The eave metal installed in Chapter 3 must already be in place beneath this membrane. The synthetic underlayment installed in Chapter 5, and the rake drip edge that Chapter 3 completes over that underlayment, both depend on the membrane installed here being continuous, adhered, and free of defects.
Skills You Will Demonstrate
- RF-019 — Prepare the deck surface for self-adhered membrane, including cleaning, drying, and primer application where required.
- RF-020 — Lay ice-and-water membrane at eaves to the required interior coverage distance without stretching or wrinkling the sheet.
- RF-021 — Install valley membrane from the low point toward the high point with correct positioning and geometry.
- RF-022 — Overlap membrane courses and end laps by the manufacturer-controlled dimension at eaves, valleys, and transitions.
- RF-023 — Seal approved penetrations, fastener heads, and membrane cuts using compatible patches or accessories.
- RF-024 — Inspect installed membrane for wrinkles, voids, fishmouths, contamination, inadequate laps, bridging, and poor adhesion, and correct defects.
Where This Skill Fits
This chapter sits between the roof-edge metal installed in Chapter 3 and the synthetic underlayment installed in Chapter 5. Eave drip edge required below the membrane must already be complete and accepted before this chapter begins. The membrane installed here becomes the last line of defense against ice-dam backup at eaves and against concentrated water flow in valleys, positions that ordinary underlayment laps alone do not adequately protect.
Every later chapter that crosses a membrane-protected area — synthetic underlayment in Chapter 5, valley shingles in Chapter 9, and any flashing chapter that meets a membrane-covered eave or valley — must integrate with this membrane in shingle-lap order rather than disturb or bridge it.
Scope and Intended Use
This chapter covers:
- reviewing climate requirements, membrane product instructions, required coverage, substrate limits, primer requirements, temperature limits, and lap dimensions
- confirming that eave drip edge required beneath the membrane is complete and accepted
- preparing the substrate at eaves and valleys, including cleaning, drying, and primer application where required
- installing self-adhered membrane at eaves to the required interior coverage distance
- installing self-adhered membrane in valleys from the low point toward the high point
- overlapping membrane courses, end laps, and secondary valley strips by the manufacturer-controlled dimension
- sealing approved penetrations, fastener heads, and membrane cuts with compatible patches or accessories
- inspecting, repairing, and documenting the completed membrane installation
This chapter does not authorize the learner to:
- install membrane over a deck that has not passed the Chapter 1 readiness inspection or that lacks required eave drip edge from Chapter 3
- install synthetic underlayment, roofing layout lines, starter strips, or shingles; those tasks begin in Chapter 5 and later chapters, only after this chapter's membrane installation is inspected and accepted
- select or substitute a membrane product, primer, or lap dimension different from the approved roofing-system specification and manufacturer instructions
- install step flashing, headwall flashing, apron flashing, or penetration flashing accessories that belong to Chapters 10 through 12, beyond sealing approved membrane cuts and fastener heads
Any deck area, corner, or transition that cannot be membraned to the manufacturer's required geometry with the tools and access available must be recorded as a deficiency and escalated before it is covered.
Reference Conventions
Establish these references before recording any finding, and use them consistently across the installation and inspection records.
| Term | Definition |
|---|---|
| Eave coverage distance | The required interior distance the membrane must extend from the exterior wall line or other controlling reference identified by the roofing-system specification |
| Course | One continuous run of membrane installed edge-to-edge with adjoining runs at the required side lap |
| End lap | The overlap between the end of one membrane length and the beginning of the next length in the same course |
| Side lap | The overlap between the long edge of one course and the long edge of the adjoining course |
| Low point / high point (valley) | The lower and upper ends of a valley run; membrane installation begins at the low point and proceeds toward the high point |
| Fishmouth | A gap or lifted edge at a lap or corner where the membrane has not fully bonded, creating an open water path |
| Bridging | Membrane spanning a plane change, corner, or deck irregularity without full contact, leaving an unsupported void beneath the sheet |
Membrane Installation and Inspection Record
Before beginning installation, record the controlling documents and site identification directly on the membrane installation record:
Project / address: ______ Roofing-system specification revision: ______ Chapter 1 readiness decision reference: ______ Chapter 3 eave drip-edge acceptance reference: ______
Membrane product: ____________ Lot number(s): ____________ Date started: ____________ Installer name: ____________
Prerequisites
- Chapter 1 roofing-readiness decision issued as proceed or conditional-proceed with all applicable corrections completed
- Chapter 3 eave drip edge required beneath this membrane installed, fastened, and accepted
- Membrane manufacturer's product instructions, required coverage, substrate limits, primer requirements, temperature limits, and lap dimensions obtained and confirmed current
- Weather and deck-surface temperature within the manufacturer's specified application range for the selected product
- Roof-access and fall-protection provisions already accepted for the site, per Chapter 2, wherever surface positions are needed
- Product and installation documentation forms available before starting
Common Field Fundamentals
Self-adhered membrane depends on two things the installer directly controls: a clean, dry substrate and correct sequencing from low point to high point, or from eave to interior, so every lap sheds water onto the layer below it. A membrane installed out of sequence, or onto a contaminated surface, will not achieve the adhesion the manufacturer's coverage and lap dimensions assume, regardless of how carefully it is rolled.
Eave zoneInterior coverage distance from the exterior wall line per the roofing-system specification
Valley zoneCentered or positioned per the approved detail; installed low point to high point
Corners & transitionsEave-to-rake corners and plane changes; no fishmouths or reverse laps
PenetrationsSealed with compatible patches or accessories at approved locations only
Side lapsManufacturer-controlled minimum overlap between adjoining courses
End lapsManufacturer-controlled minimum overlap between lengths in the same course
Substrate conditionClean, dry, and primed only where the manufacturer requires it
Reference methodEvery course measured from a fixed eave or valley reference, not by eye
Substrate Preparation and Primer
Inspect the deck for dust, moisture, frost, oil, loose fibers, protrusions, gaps, and damaged sheathing before staging any membrane. Clean and dry the substrate using methods permitted by the membrane manufacturer. Apply compatible primer only where the manufacturer requires it, and allow the primer to reach the specified condition before membrane placement begins.
RF-019 – RF-024
Membrane Installation / Water-Control Preparation
Ice-and-Water Shield Installation at Eaves and Valleys
A. Finished-Work Specification
Deliverable: continuous, fully adhered self-adhered membrane covering the required interior eave distance and the complete length of every required valley from low point to high point, with side laps, end laps, and corner transitions installed at the manufacturer-controlled dimension, penetrations and cuts sealed with compatible accessories, defects repaired, and product, lot, weather, and inspection information recorded.
B. Governing Documents
| Document | Confirmed Current | Notes |
|---|---|---|
| Roofing-system specification | ||
| Membrane manufacturer's product instructions | ||
| Climate / coverage requirement reference | ||
| Chapter 1 roofing-readiness decision | ||
| Chapter 3 eave drip-edge acceptance record | ||
| Valley detail (open, closed-cut, or woven, as applicable to later chapters) |
C. Acceptance Standards
| Check | Standard |
|---|---|
| Eave drip-edge prerequisite | Confirmed complete and accepted before membrane installation begins |
| Substrate condition | Clean, dry, and free of frost, oil, loose fibers, protrusions, gaps, and damaged sheathing, or each item corrected before membrane placement |
| Primer | Applied only where required by the manufacturer and allowed to reach the specified condition before membrane placement |
| Eave coverage distance | Meets or exceeds the required interior distance measured from the controlling reference, without an unsupported seam |
| Valley installation | Installed from the low point toward the high point, centered or positioned per the approved detail |
| Side laps and end laps | Meet or exceed the manufacturer-controlled minimum overlap at every course and length transition |
| Corners and transitions | Free of fishmouths, reverse laps, and trapped air |
| Penetrations and cuts | Sealed using manufacturer-approved patches or accessories at approved locations only |
| Surface condition | Free of wrinkles, voids, fishmouths, contamination, inadequate laps, bridging, and poor adhesion, or each item corrected and rechecked |
| Documentation | Product, lot, weather conditions, locations, laps, repairs, and inspection results recorded before Chapter 5 begins |
D. Required Project Sequence
- Review climate requirements, membrane product instructions, required coverage, substrate limits, primer requirements, temperature limits, lap dimensions, and valley details. Confirm the revision or date on each document before using it, and record confirmation on the governing-documents table above.
- Confirm that eave drip edge required below the membrane is complete and accepted. Locate the Chapter 3 acceptance record for the eaves receiving membrane. If the record cannot be located or shows an open item, stop this chapter and route the project back before continuing.
- Inspect the deck for dust, moisture, frost, oil, loose fibers, protrusions, gaps, and damaged sheathing. Perform this inspection at every eave and valley area scheduled for membrane, and record any condition requiring correction before cleaning.
- Clean and dry the substrate using methods permitted by the membrane manufacturer. Use only the cleaning method identified in the product instructions; do not use a solvent, degreaser, or drying method the manufacturer does not permit.
- Apply compatible primer only where required and allow it to reach the specified condition. Apply primer solely to the areas and substrates the manufacturer identifies, and confirm the required flash-off or cure condition before proceeding.
- Measure the required eave coverage from the exterior wall line or other controlling reference. Record the measured coverage distance for each eave on the installation record before cutting membrane lengths.
- Plan membrane widths and course locations so the required interior coverage is achieved without an unsupported seam. Lay out the course plan on paper or the installation record before beginning, identifying every side lap and end lap location.
- Precut manageable membrane lengths and keep adhesive faces protected until placement. Cut lengths on a supported staging surface, and keep release film in place until each length is positioned at its installation location.
- Establish a straight eave reference line. Snap or otherwise mark a straight reference parallel to the eave using the drip-edge relationship identified in the roofing-system specification.
- Align the first membrane section without stretching it. Position the first length to the eave reference line, confirming square alignment before removing any release film.
- Remove release film in controlled increments while pressing the membrane from the center outward. Peel back only the portion of film needed for the next contact area, and press outward from the center of the sheet to avoid trapping air.
- Roll or press the membrane using the specified tool and pressure method. Use the membrane roller or hand roller identified in the tools list, working from the center of the sheet toward each edge and end.
- Install successive sections with the manufacturer-controlled end and side laps. Measure each lap against the manufacturer's minimum dimension before pressing the lap into contact, and record the lap dimension used.
- Treat eave corners, rake transitions, and changes in plane without fishmouths or reverse laps. Form each corner and transition according to the manufacturer's detail, orienting every lap so the upper piece sheds onto the lower piece.
- Prepare valleys by confirming deck support, geometry, and cleanliness. Inspect each valley for adequate width, straight framing support, and a clean substrate before staging valley membrane.
- Center or position the valley membrane according to the approved detail and install from low point toward high point. Establish the valley centerline reference before removing release film, and begin installation at the identified low point of the valley run.
- Add required secondary valley strips or transition patches in shingle-lap order. Where the approved detail calls for a secondary strip or patch, install it so each added piece sheds onto the piece installed before it.
- Seal approved penetrations, fastener heads, or membrane cuts using compatible patches or accessories. Use only the patch or accessory identified in the manufacturer's instructions, and seal only at approved penetration locations confirmed against the Chapter 1 readiness record.
- Inspect for wrinkles, voids, fishmouths, contamination, inadequate laps, bridging, and poor adhesion. Inspect the full installed area from an approved position, checking every lap, corner, and valley run against the acceptance standards above.
- Repair defects using the manufacturer-approved patch dimensions and sequence. Correct each identified defect using the specific patch size and lap sequence the manufacturer requires; do not rely on hand pressure alone to correct a void or fishmouth.
- Protect the membrane from unnecessary traffic, prolonged exposure, and incompatible materials. Limit foot traffic on completed membrane to what is required for the next course, and keep incompatible solvents, sealants, or coatings off the installed surface.
- Record product, lot information, weather conditions, locations, laps, repairs, and inspection results. Complete the membrane installation record before beginning Chapter 5, including every repair made and its location.
Common Membrane Installation Checks
Apply the same checks to every eave and valley area receiving membrane, regardless of roof size or configuration.
- Prerequisite check: confirm the Chapter 3 eave drip-edge acceptance record exists for each eave before membrane installation begins there.
- Substrate check: confirm the deck is clean, dry, and free of frost, oil, loose fibers, protrusions, gaps, and damaged sheathing before membrane placement.
- Coverage check: confirm eave membrane meets or exceeds the required interior coverage distance measured from the controlling reference.
- Sequence check: confirm valley membrane was installed from the low point toward the high point, with every lap shedding onto the layer below it.
- Lap check: confirm every side lap and end lap meets or exceeds the manufacturer-controlled minimum dimension.
- Surface check: confirm the finished membrane is free of wrinkles, voids, fishmouths, contamination, inadequate laps, bridging, and poor adhesion, or each item is corrected and rechecked.
- Documentation check: confirm product, lot, weather, locations, laps, repairs, and inspection results are recorded before Chapter 5 begins.
Complete the Membrane Installation and Inspection Record in the Inspection Checklist section below before beginning Chapter 5.
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Failure Points and Troubleshooting
Cleanup
This chapter ends with a fully adhered, inspected membrane system and a complete installation record, not loose release film and unlogged repairs.
- Collect and dispose of all release film and membrane cutoffs using an approved method that does not discharge material from the roof edge
- Wipe down tools used for primer or adhesive contact per the product instructions before storage
- Store unused membrane rolls protected from moisture, sunlight, and temperature extremes per the manufacturer's storage instructions
- Compile the product, lot, weather, location, lap, repair, and inspection records into the project record
- Transfer the completed membrane installation record to the location Chapter 5 will reference before beginning synthetic underlayment
Field Terms
- Self-Adhered Membrane
- A roofing underlayment product with a factory-applied adhesive face that bonds directly to the deck substrate without separate fasteners across its field.
- Eave Coverage Distance
- The required interior distance membrane must extend from the exterior wall line or other controlling reference.
- Side Lap
- The overlap between the long edges of two adjoining membrane courses.
- End Lap
- The overlap between the ends of two membrane lengths within the same course.
- Fishmouth
- A gap or lifted edge at a lap or corner where the membrane has not fully bonded, creating an open water path.
- Bridging
- Membrane spanning a plane change, corner, or deck irregularity without full contact, leaving an unsupported void beneath the sheet.
- Low Point / High Point
- The lower and upper ends of a valley run; installation proceeds from the low point toward the high point.
- Primer
- A compatible product applied to specific substrates, only where the membrane manufacturer requires it, to improve adhesion.
- Shingle-Lap Order
- An installation sequence in which each added layer sheds water onto the layer installed before it.
Skill Check
- Why must the Chapter 3 eave drip-edge acceptance record be confirmed before this chapter's membrane installation begins?
- What substrate conditions must be corrected before self-adhered membrane is placed, and how is primer treated differently from general substrate preparation?
- From what reference is the required eave coverage distance measured, and why does that reference matter?
- Why must valley membrane be installed from the low point toward the high point rather than in the opposite direction?
- What is the difference between a side lap and an end lap, and why must both meet a manufacturer-controlled minimum dimension?
- What defines a fishmouth, and what correction method is required when one is found during inspection?
- Under what condition is a learner authorized to seal a penetration during this chapter, and what must be checked first?
- Why is a stretched or wrinkled membrane section a defect even if it appears fully adhered at its edges?
- What information must be recorded on the membrane installation record before Chapter 5 begins?
- Why does this chapter prohibit installing synthetic underlayment, layout lines, or shingles during its own scope?
Competency Rubric
| Competency | Independent Pass Standard | Not Demonstrated | With Assistance | Independently |
|---|---|---|---|---|
| RF-019 | Prepares the deck surface for membrane, including cleaning, drying, and primer application only where required, without proceeding on a contaminated or damp substrate | |||
| RF-020 | Installs eave membrane to the required interior coverage distance without stretching or wrinkling the sheet | |||
| RF-021 | Installs valley membrane from the low point toward the high point with correct centering and geometry per the approved detail | |||
| RF-022 | Achieves the manufacturer-controlled minimum side lap and end lap at every course and length transition, including corners and transitions | |||
| RF-023 | Seals only approved penetrations, fastener heads, and membrane cuts using manufacturer-approved patches or accessories | |||
| RF-024 | Inspects the completed membrane for wrinkles, voids, fishmouths, contamination, inadequate laps, bridging, and poor adhesion, and corrects every defect found |
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 — Membrane Installation and Inspection Record
| Item | Condition Found | Correction Required | Corrected (Y/N) | Reinspection Result |
|---|---|---|---|---|
| Substrate condition (cleaning / drying) | ||||
| Primer application (where required) | ||||
| Eave coverage distance — Eave 1 | ||||
| Eave coverage distance — Eave 2 | ||||
| Valley membrane — low-to-high sequence | ||||
| Side laps | ||||
| End laps | ||||
| Corners and plane-change transitions | ||||
| Penetration and cut sealing | ||||
| Surface condition (wrinkles / voids / fishmouths / bridging) |
Membrane installation decision: ______ (Accepted / Accepted with Listed Corrections / Stop-Work) Date: ____________ Installer name: ____________
Performance Check
With the installation complete, review the Membrane Installation and Inspection Record against the Acceptance Standards table and confirm the eave drip-edge prerequisite was verified, the substrate was clean and dry with primer applied only where required, eave coverage meets or exceeds the required interior distance at every eave, valley membrane was installed from low point to high point at every required valley, every side lap and end lap meets the manufacturer-controlled minimum, every corner and transition is free of fishmouths and reverse laps, every approved penetration and cut is sealed, and every identified defect has been corrected and rechecked. Sign the membrane installation decision before beginning Chapter 5.
Chapter Closeout
You have completed the fourth chapter in the roof-installation sequence: installing self-adhered ice-and-water shield membrane at required eaves, valleys, and vulnerable transitions. This chapter required you to prepare the substrate for membrane (RF-019), install eave membrane to the required coverage distance (RF-020), install valley membrane from low point to high point (RF-021), overlap courses and transitions correctly (RF-022), seal approved penetrations and cuts (RF-023), and inspect and correct the completed membrane (RF-024).
You now have a fully adhered, inspected membrane system in place over every deck area the roofing-system specification identifies as requiring it. That membrane carries directly into the next chapter: installing continuous synthetic underlayment over the deck and this membrane, maintaining the same low-to-high, shingle-lap water path this chapter established.
Store the completed membrane installation record with the project record. Chapter 5 requires this record before synthetic underlayment begins.