Roofing, Siding & Exterior Glossary
Plain-English definitions of the roofing, siding, window and exterior terms you’ll hear during a project — written for Minnesota homeowners by Three Rivers Contracting.
Jump to: Roofing · Roof Anatomy · Ventilation · Siding · Windows & Doors · Gutters & Drainage · Storm & Safety · Process & Permits
Roofing Materials
Asphalt Shingle
The most common roofing material. “Architectural” (dimensional) shingles are thicker and longer-lasting than flat “3-tab” shingles.
Class 4 (Impact-Resistant)
The top hail-impact rating (survives a 2″ steel ball dropped from 20 ft). Common on premium asphalt and composite shingles and can earn an insurance discount in Minnesota.
Standing-Seam Metal
A metal roof with raised, interlocking vertical seams and hidden fasteners — sheds snow and lasts 50+ years.
Composite / Synthetic Shingle
Engineered polymer or recycled-rubber shingles that mimic slate or shake and absorb hail impact without cracking.
TPO
A single-ply white commercial membrane with heat-welded seams; reflective and energy-efficient for flat/low-slope roofs.
EPDM
A single-ply synthetic-rubber commercial membrane (“rubber roof”) that stays flexible in deep cold.
Built-Up Roof (BUR) / Ballasted
A multi-ply flat roof of felts and asphalt, often topped with gravel/river-rock ballast that shields the membrane.
Roof Anatomy & Accessories
Decking / Sheathing
The plywood or OSB layer nailed to the rafters that the roof is built on. Older Twin Cities homes often have gapped “spaced” decking that should be replaced with solid sheathing.
Underlayment
The water-shedding layer over the decking, under the shingles. Premium synthetic (e.g., GAF Tiger Paw) replaces old felt paper.
Ice & Water Shield
A self-sealing waterproof membrane at eaves, valleys, and penetrations — the #1 defense against ice dams.
Drip Edge
Metal flashing at the roof edges that directs water into the gutter instead of behind it.
Flashing
Metal pieces that seal roof transitions — chimneys, walls, valleys, skylights. The most common place roofs leak.
Step Flashing
Overlapping flashing woven into the shingles where a roof meets a wall.
Valley
The V where two roof slopes meet; lined with ice & water shield and often open metal to handle heavy runoff.
Ridge Cap
Purpose-built shingles that cap the peak (ridge) of the roof.
Fascia
The horizontal board along the roof edge that the gutters attach to.
Soffit
The underside of the roof overhang; usually vented to provide attic intake air.
Ventilation
Ridge Vent
A low-profile exhaust vent along the roof peak that lets hot, moist attic air escape.
Box / Static Vent
Individual roof vents used where a continuous ridge vent isn’t possible. (Never mix exhaust vent types on one attic — it short-circuits airflow.)
Intake Ventilation
Soffit or edge vents that let fresh air in at the eaves — must be balanced with exhaust to work.
Knee-Wall Attic
Short walls along sloped ceilings in story-and-a-half / Cape Cod homes that create hard-to-vent triangular voids — a top ice-dam cause in older neighborhoods.
Baffle (Air Chute)
A channel that keeps the air path open from the soffit up past the insulation to the ridge.
Siding & Exterior
Fiber Cement (James Hardie)
A durable cement-based siding; Hardie’s HZ10 line is formulated for northern freeze-thaw climates.
Engineered Wood (LP SmartSide)
Treated wood-strand siding that flexes on hail impact; available with Diamond Kote’s 30-year no-fade finish.
Weather-Resistive Barrier (WRB)
The house wrap behind the siding that manages any water that gets past it — required by code.
Rainscreen
A drainage gap behind the siding that lets the wall dry, preventing rot in cold climates.
Manufactured Stone Veneer
Lightweight cast-stone accents for entries, columns, and wainscots.
Board & Batten
Vertical siding with wide boards and narrow battens — a popular accent for modernizing older homes.
Stucco / EIFS (Dryvit)
Traditional or synthetic stucco. Older and 1990s-era systems can trap moisture and rot framing — often replaced with modern siding.
J-Channel
Trim that receives the cut edges of siding around windows, doors, and penetrations.
Windows & Doors
Full-Frame Replacement
Removing a window to the rough opening (studs) so the frame, flashing, and insulation can all be renewed and the full glass size kept.
Insert / Pocket Replacement
A new window set inside the existing frame — faster and cheaper, but only valid if the old frame is sound, and it shrinks the glass.
U-Factor
How well a window resists heat loss — lower is better. Minnesota homes benefit from low U-factors (triple-pane can reach ~0.20).
Low-E Glass
A microscopically thin coating that reflects heat to improve efficiency (Andersen’s Low-E4/SmartSun).
Egress Window
A window large enough for escape/rescue — required by Minnesota code for a legal basement bedroom.
Casement Window
A window hinged on the side that cranks outward; seals tightly against wind.
Double-Hung Window
A classic window with two sashes that slide vertically; easy to clean.
Gutters & Drainage
Seamless Gutters
Gutters formed from one continuous piece on site, so there are no joints to leak.
Downspout
The vertical pipe that carries water from the gutter to the ground.
Gutter Guard
A cover or screen that keeps debris out so water flows freely — helps prevent clogs and ice dams.
French Drain
A gravel-and-pipe trench that moves water away from the foundation to prevent basement water.
Storm, Insurance & Safety
Ice Dam
A ridge of ice at the cold eave (from attic heat melting roof snow) that backs water up under the shingles.
Snow Drift / Drift Load
Wind-piled snow that overloads valleys, dormers, and lower roofs beyond their design load.
EPA RRP (Lead-Safe)
Federal rule for disturbing paint in pre-1978 homes; requires a certified firm and lead-safe work practices. Three Rivers is an EPA Lead-Safe Certified Firm.
Asbestos
A hazardous material in some old siding, shingles, and insulation. In Minnesota it must be tested (or assumed) and removed by licensed abatement before disturbance.
ACV vs. RCV
Insurance terms: Actual Cash Value (depreciated) vs. Replacement Cost Value (full replacement). Matters on hail/wind claims.
Process & Permits
MN Building Contractor (BC) License
The state license required to contract residential work in Minnesota. Verify any contractor at the Department of Labor & Industry. (Three Rivers: #BC760638.)
Building Permit
Required by Minnesota’s State Building Code to re-roof, re-side, or replace windows; the work is then inspected. We pull permits for you.
Tear-Off
Removing the old roof or siding down to the deck/sheathing so the new system starts clean — opposite of a “recover/overlay.”
GAF Certified / OC Platinum
Top manufacturer certifications held by only a small percentage of contractors — they unlock the strongest warranties. Three Rivers holds both.
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