Steep-slope
Homes and water-shedding roof fields
Compare primary coverings first, then check valleys, ventilation, flashing, penetrations, roof edges, and any lower-slope tie-ins.
Materials hub · 7 current category guides
Compare Roofing Materials and Roof-System Paths
Start with slope, building type, current condition, exposure, drainage, and transition details. Then open the guide that matches the roof system—not just the product name.
Compare primary coverings, low-slope membranes, qualified restoration, supporting details, and roof-edge drainage without treating them as interchangeable products.
Self-routing
Start with roof geometry and building use
Slope determines how the roof manages water. Building use, rooftop equipment, access, and transitions then narrow the practical material path.
Low-slope
Commercial and membrane roof areas
Start with condition, moisture, drainage, rooftop equipment, traffic, insulation, and the existing assembly before choosing a membrane path.
Mixed-slope
Additions, porches, walls, and material changes
A roof can need more than one compatible system. Slope breaks and material changes should be designed as transitions, not improvised in the field.
Roof edge
Gutters, outlets, and runoff routing
When the main issue is overflow, concentrated valley water, fascia support, or discharge, route drainage with the roof system instead of treating it as trim.
Current inventory
Compare all material and system guides
These 7 routes do different jobs. Primary coverings and membranes manage the roof field; coatings are a qualified restoration path; supporting details and gutters complete transitions and water control.
Swipe or scroll horizontally to compare every planning column.
| Guide | Roof role | Slope fit | Building fit | Condition path | Details that decide performance |
|---|---|---|---|---|---|
| Asphalt Shingles | Primary steep-slope covering | Steep-slope roof fields; low-slope tie-ins need a separate compatible detail. | Homes and other suitable steep-slope buildings. | Localized repair when the surrounding assembly remains serviceable; replacement when aging or failure is broad. | Deck, underlayment, valleys, ventilation, flashings, penetrations, and roof edge. |
| Roof Tile | Primary steep-slope, water-shedding assembly | Steep-slope; lower-slope conditions require an approved assembly and project-specific detailing. | Homes and other buildings where profile, weight, and architectural fit are appropriate. | Tile replacement or repair depends on profile availability and the condition of underlayment, flashings, deck, and fasteners. | Structural load, underlayment, battens, valleys, flashings, penetrations, and tile matching. |
| Metal Roofing | Concealed- or exposed-fastener roof system | Profile- and assembly-specific; standing seam and exposed-fastener systems are not interchangeable. | Homes, commercial buildings, and mixed-system roofs where the selected profile fits. | Repair or replacement depends on panel condition, corrosion, attachment, substrate, and transition details. | Thermal movement, clips or fasteners, compatible metals, underlayment, penetrations, and edges. |
| TPO / PVC | Thermoplastic single-ply membrane system | Low-slope roof areas with drainage and transition details designed as part of the selected system. | Commercial and other suitable low-slope roof areas. | Repair, recover, or replacement depends on moisture, substrate, insulation, attachment, and seam condition. | Insulation, cover board, seams, drains, scuppers, curbs, penetrations, edges, and traffic. |
| Modified Bitumen | Layered asphaltic membrane system | Low-slope roof areas planned around substrate, layering, flashings, and positive drainage. | Commercial and other suitable low-slope roof areas. | Localized repair, recover, or replacement depends on moisture, substrate, existing layers, and detail condition. | Base and cap roles, application method, insulation, cover board, flashings, drains, and edges. |
| Roof Coatings | Restoration system, not a default replacement | Compatible existing low-slope roofs after the substrate and selected coating system are qualified. | Commercial and other suitable low-slope buildings with a serviceable existing roof. | Restoration only after leaks and wet areas are addressed and drainage, compatibility, and adhesion are reviewed. | Moisture review, repairs, preparation, primer, reinforcement, coating build, and drainage. |
| Gutters | Runoff collection and discharge system | Roof edges and concentrated runoff paths on steep- and low-slope buildings. | Buildings where eaves, fascia, outlets, downspouts, and discharge paths can be coordinated. | Repair or replacement depends on profile, support, seams, outlets, downspouts, fascia, and discharge condition. | Valleys, eaves, profile, outlets, downspouts, fascia support, overflow, and discharge routing. |
Material library
Open the guide that matches the roof
Each category page goes deeper on the assembly, component relationships, field constraints, and related service path.
Primary roof covering
Asphalt Shingles
A steep-slope covering planned with the deck, underlayment, ventilation, flashings, valleys, penetrations, and roof edge.
- Steep-slope
- Residential
- Repair / replacement
Primary roof covering
Roof Tile
Concrete and clay tile assemblies where underlayment, flashing, fastening, profile matching, and structural load all matter.
- Steep-slope
- Residential
- Load + underlayment
Primary roof covering
Metal Roofing
Standing-seam and exposed-fastener systems compared by profile, slope, attachment, movement, corrosion exposure, and transitions.
- Profile-specific slope
- Residential / commercial
- Movement + corrosion
Primary low-slope membrane
TPO / PVC
Thermoplastic single-ply membrane systems planned around seams, attachment, insulation, drainage, curbs, penetrations, and traffic.
- Low-slope
- Commercial
- Repair / recover / replace
Primary low-slope membrane
Modified Bitumen
Layered asphaltic low-slope systems compared by substrate, application method, base and cap roles, flashings, and drainage.
- Low-slope
- Commercial
- Layered assembly
Condition-dependent restoration
Roof Coatings
A condition-dependent restoration path for compatible low-slope roofs after leaks, wet areas, adhesion, and drainage are addressed.
- Restoration path
- Low-slope
- Qualification required
Roof-edge drainage
Gutters
Roof-edge drainage planned around profile, outlets, downspouts, fascia support, concentrated runoff, and discharge routing.
- Roof-edge drainage
- Runoff routing
- Fascia + outlets
Condition before product
Repair, restoration, recover, and replacement are different paths
Material selection comes after the roof condition and project scope are clear. The same membrane or covering can be plausible in one scope and wrong in another.
Repair
The issue appears localized
An isolated issue may be a repair candidate after the surrounding material and assembly are confirmed to support compatible, durable work.
Restoration
A low-slope roof may still be serviceable
Coating is a qualification-based option after leaks and wet areas are addressed and the roof is checked for drainage, compatibility, adhesion, and remaining serviceability.
Recover / reroof review
The existing assembly may remain in place
Recover feasibility is project-specific. Existing layers, moisture, substrate, attachment, insulation, drainage, manufacturer requirements, and code path all need review.
Replacement
Failure or aging is system-wide
Replacement planning makes more sense when conditions are broad, layers are incompatible, hidden components are compromised, or the owner needs a full system reset.
Whole-system planning
Supporting details, drainage, penetrations, and transitions stay connected
The roof field is only one part of water control. Use these relationships to route mixed-scope questions without turning every detail into a separate primary material.
Supporting and transition details
Underlayment, flashing, fasteners, ventilation, sealants, curbs, and compatible tie-ins connect the primary material to walls, penetrations, valleys, ridges, and slope changes.
Roof-edge and low-slope drainage
Valleys, gutters, outlets, downspouts, drains, scuppers, overflow paths, and discharge routing form one water-management chain.
Skylights, curbs, and penetrations
The unit or equipment is only part of the detail. Flashing, curb height, back pans, membrane transitions, adjacent drainage, and reroof timing can change the right scope.
Traffic, equipment, and maintenance access
Low-slope roofs need intentional service routes around rooftop equipment. Walk paths, penetrations, drains, repairs, and recurring maintenance should be planned together.
Exposure changes the details
Check the environment before relying on a generic material claim
These are planning checkpoints, not property-specific code determinations. Final requirements depend on the address, scope, selected assembly, current manufacturer documents, and local review.
Coastal or moisture-heavy exposure
Review compatible metals, corrosion exposure, finish selection, drying conditions, underlayment, edges, flashings, and wind-driven moisture paths.
Inland heat and strong sun
Review thermal movement, sealants and boots, ventilation, rooftop traffic, membrane or coating suitability, and cool-roof compliance when it applies.
Trees, debris, and concentrated runoff
Prioritize valleys, roof-to-wall areas, gutters, drains, scuppers, outlets, overflow paths, and safe discharge away from the building.
Fire exposure or WUI review
Confirm property-specific requirements, the rated roof assembly, gaps, vents, attachments, gutters, debris control, and local amendments. A material name alone is not the compliance path.
Claim discipline
Separate product claims, code requirements, and field conditions
Manufacturer instructions are product-specific
Slope, substrate, attachment, compatibility, fire or wind listings, chemical resistance, warranty eligibility, and installation details must be checked for the selected product and assembly.
Energy compliance is project-specific
California's 2025 Energy Code applies to permit applications filed on or after January 1, 2026. Cool-roof requirements vary by building and project type, climate zone, slope, roof area, and compliance path.
Field condition can change the answer
Deck and substrate condition, moisture, drainage, existing layers, penetrations, traffic, workmanship, and repair history can rule out an otherwise plausible material path.
Choose the service path
Route the roof condition before requesting a product
Choose the closest path and describe the roof type, symptom, slope changes, drainage, and any skylight or rooftop-equipment details in the request.
Roof inspections
Use when the entry point, assembly condition, or repair-versus-replacement path is not yet clear.
Open service Roof repairUse for localized leaks, flashing failures, damaged covering, penetrations, valleys, or roof-edge details.
Open service Roof replacementUse when the whole assembly needs life-cycle planning rather than another isolated repair.
Open service Commercial roofingUse for low-slope roofs, drains, scuppers, seams, curbs, rooftop equipment, maintenance, and capital planning.
Open service Gutters and drainageUse when runoff collection, outlet sizing, sagging, downspout routing, fascia staining, or discharge is the main issue.
Open service Preventative maintenanceUse when the roof remains serviceable and the goal is scheduled checks, drainage review, minor corrections, and condition tracking.
Open serviceNeed help narrowing the material path?
Share the roof type, slope, leak or repair history, drainage, transitions, and project goals. We will help route the condition to inspection, repair, restoration review, commercial planning, or replacement.