What Are The Basics of Roofing?

What Are The Basics of Roofing

What Are The Basics of Roofing? Roofing is essential to any building, providing critical protection from the elements. While the specifics can get complex, the fundamentals of roofing center around a few key concepts.

Key Takeaways

  • Roofs are typically composed of structural materials like wood, metal, or concrete and covered with waterproofing materials like shingles, tiles, or membrane sheets.
  • The main parts of a roof include the deck, underlayment, waterproofing layer, and flashing details around joints and edges.
  • Common roofing terms describe pitch, slope, vents, valleys, rakes, and other parts.
  • Elements like shape, materials, layers, and details differ based on climate conditions and building type.
  • Roofing requires physical fitness, balance, attention to detail, and comfort working at heights.
  • Primary tools include ladders, hammers, saws, utility knives, nail guns, shovels, and pry bars.
  • Different roof types have upsides and downsides regarding cost, durability, aesthetics, climate appropriateness, etc.
  • Constructing a roof involves planning, tear-off, deck prep, underlayment installation, waterproofing layer installation, flashing, and testing.

What Are Roofs Made Of?

The primary function of a roof is to protect the building and its residents from outdoor elements. To achieve this, roofs have a structural foundation and layers to provide durability, weather resistance, and drainage.

Structural Foundation Materials

The base structure of a roof is called the roof deck. Common decking materials include:

  • Wood – Typically plywood or oriented strand board (OSB). Affordable option.
  • Metal – Steel or aluminum decking. Lightweight but durable.
  • Concrete – Poured or precast concrete. Heavy but long-lasting.
  • Composite – Manufactured wood and plastic composites. Balances cost and performance.

The incline angle and shape provided by the roof deck and support framing are key for water drainage.

Protective Top Layers

On top of the deck, roofing systems have additional layers to shed water and handle weather exposure:

  • Underlayment is a moisture barrier layer of felt, rubberized asphalt, or ice and water shield membranes. Prevents water intrusion.
  • Waterproofing – The top exterior layer deflects water and withstands the elements. Common options include shingles, tiles, metal panels, and commercial membrane sheets.
  • Flashing – Sheet metal components designed to seal joints, valleys, vents, and edges from moisture entry. Usually galvanized steel, copper, or aluminum.

Additional roof elements like vents, drains, and treatments like radiant barriers can also be installed.

Main Components of a Roof

While roofs may look simple from the ground, they have several components working together as a system:

Roof ComponentDescription
DeckingThe structural foundation is made of sheathing-like plywood over roof trusses.
UnderlaymentA barrier layer to prevent moisture intrusion, usually roofing felt.
WaterproofingThe top exterior surface deflects water. Shingles and other roof coverings.
FlashingSeals edges and joints vulnerable to leaks if exposed.
VentsAllow airflow to regulate temperature and moisture.
ValleysJoints where two sloped roof sections meet to channel water drainage.
ParapetsRaised edges around flat roof perimeters to prevent water pooling.
DrainsDownspouts, scuppers, and gutters to direct rainwater runoff away from the structure.
EavesRoof edges that overhang past walls, usually with exposed rafters. Help shade and protect facades.

Common Roofing Terms

In addition to physical components, the roofing industry employs some key terminology:

Roofing TermDescription
PitchThe roof surface’s steepness angle is measured by rise over run. It can range from near flat to vertical.
SlopeRoof pitch converted to a degree angle for calculations. A 4/12 pitch equates to an 18.5-degree slope.
RakeThe angled edge of a roof along sloped sides. Usually, where gutters attach.
SheathingThe deck substrate material is installed first to the structural framing of the roof.
TrussesEngineered, prefabricated triangular wood or metal structural supports shaped to carry roof load forces.
ReroofingThe process of installing all new roofing components over an existing roof structure vs. new construction builds.

Popular Roof Design Elements

Many factors influence roof design, including:

Building Function

Roof shapes compatible with a building’s layout and interior space are prioritized. Home styles often dictate roof lines. Commercial roofs emphasize weatherproofing for ongoing occupancy. Roofs for storage spaces focus on protecting contents from the elements.


Regions with heavy snowfall warrant steeply angled roofs to prevent accumulation. Flat roofs allow water drainage in hot climates but may preclude snowy areas. Coastal environments demand durable materials to withstand high winds and salt corrosion exposure.


A roof impacts curb appeal and architectural style. Many homeowners choose luxury materials like slate, tile, or metal for visual interest over basic asphalt shingles. Some roofing provides a planting surface for green roofs.

Occupant Use

Roofs may need to bear live loads for occupant access if they are housing recreation spaces, HVAC equipment, solar panels, or green roof gardens. These require reinforced structural support.


Buildings must meet roofing codes related to materials, durability, connections, load ratings, and health/safety. Roofs safeguard occupants and interior contents.

Standards for commercial structures are more stringent than residential ones. Special stipulations regarding wind, seismic, snow load, and wildfire building codes may apply.

Skills Required To Be a Roofer

Installing and repairing roofs require skills:

  • Physical fitness – the ability to carry heavy materials up and down ladders repeatedly in variable weather conditions
  • Balance and coordination – important when moving on angled and slippery roof surfaces
  • Spatial perception – correctly identifying roof planes, angles, and measurements
  • Technical knowledge – understanding of roofing best practices, methods, and building codes
  • Attention to detail – catch and seal any moisture entry vulnerability points with perfect flashing placements
  • Time management skill – complete roof tear-off replacement in a set number of days amidst weather delays
  • Customer service – interact positively with building owners throughout the roofing project

A good roofer has a sharp eye, steady foot, strong back, meticulous diligence, practical know-how, and a personable manner.

Tools Needed For Roofing

Roofing work requires a variety of standard and specialized tools:

Ladders and scaffoldingTo safely access work areas at height.
HammersFor nailing shingles and flashing into place.
Saws and KnivesCut roof materials to measured sizes.
Roof jacksFlat platforms to kneel or stand on sloped roofs.
Nail gunsPowered fastener tools to improve speed and accuracy.
ShovelsRemove old roofing materials and debris.
Harnesses and ropesFall arrest equipment for working on roof edges.
Pry barsLift, adjust, and secure decking, underlayment, and shingles.
Tin snipsCut, shape, and notch flashing pieces.
Caulk gunsSeal joints and gaps fully against moisture.
Tape measureConfirm layout dimensions and estimates.
Chalk lineSnap straight lines to align courses.
Utility knifeVersatile manual cutter.

Always prioritize safety and efficiency when selecting roofing tools. Choose durable, reliable equipment and never compromise on safety gear like harnesses and helmets, as they are essential for preventing workplace accidents.

Pros vs Cons: Types of Roofs

Many roofing materials and styles exist, each with advantages and disadvantages:

Type of RoofingProsCons
Asphalt ShingleAffordable, easy to install, variety of styles and colorsShorter lifespan (15-30 years), less durable in extreme weather
Metal RoofingVery long lifespan (50+ years), fire/hail resistant, low maintenanceHigher material costs, noisy, and rain protection required
Tile RoofingExcellent curb appeal, very long lifespan (100 years), fire-resistantHeavy, easier damage from falling limbs, high material and labor costs
Flat RoofingMaximizes square footage, accommodates HVAC systems, rooftop use potentialRequires rigorous maintenance, vulnerable to standing water and leakage over time
Green RoofingEnvironmentally friendly, energy efficiency gains, filters rainwater runoff.Very high installation costs, significant structural support required, maintenance intensive

When considering a roofing type, balance aesthetics with practicality. A visually appealing roof adds to your home’s curb appeal, but choosing materials that suit your climate and maintenance preferences is equally important.

Roof Building: Step by Step

Roof Building: Step by Step

Here’s a simple step-by-step guide for the process of building a roof:


  • Gather building dimensions.
  • Identify existing damage and design replacements.
  • Order customized materials and secure necessary permits.
  • Schedule subcontractor equipment and crews, considering weather forecasts.


  • Remove all old roofing layers down to the roof deck.
  • Properly dispose of the debris.
  • Inspect the deck’s integrity and repair or replace weakened sections.

Deck Preparation

  • Thoroughly clean the deck.
  • Install any necessary crickets, slope adjustments, or radiant barriers.
  • Prime surfaces as required.

Underlayment Installation

  • Roll out moisture barrier underlayment, like felt paper or ice/water shield membrane, following building codes.

Waterproofing Installation

  • For shingle roofs:
    • Start with the starter course at the bottom edge, ensuring overhangs.
    • Use chalk lines for aligned courses and nails in place.
    • Interlace layers, either diagonally or straight, depending on the style.
    • Apply flashing throughout, sealing all vulnerabilities.
  • For tile roofs:
    • Follow procedures for battening, using mortar, and precise tile placements.
  • For membrane roofs:
    • Apply adhesive and weld seams as needed.

Inspections and Approvals

  • Go through various checkpoints for fire, windstorm, and code compliance, especially in commercial projects.

Finishing Touches

  • Complete final terminations.
  • Install ridge vents, curbs, gutters, and skylights, and replace roof jacks.
  • Perform thorough cleanup of both grounds and interiors.
  • Seal any roofing penetrations made for HVAC vents, plumbing stacks, etc.

Following this guide with quality materials and proper technique will ensure a new roof provides decades of protection, requiring only periodic inspection and minor upkeep.

Roof Maintenance Best Practices

To maximize roof lifespan, building owners should follow proactive maintenance best practices:


Inspect roofs twice per year, in spring and fall. Use binoculars and drone cameras to see all areas. Look for damaged materials, erosion, ponding water, vegetation growth, leaked water stains, or exposed underlayment. Immediately correct any deficiencies found.


Clear debris from the valley and drain channels so water can flow freely. Remove piled leaves, branches, and soil from low areas. Have HVAC and vent hoods professionally cleaned to avoid grease residue. Employ gutter guards.

Snow and Ice

Promptly address heavy snow or long icicles over roof edges, which risk collapse and ice dam leaks. Carefully shovel or rake snow loads towards drains. Use salt at downspouts to allow meltwater to exit.


Attic ventilation regulates temperature and moisture levels, which can otherwise damage roof sheathing and shingle integrity over time. Install ridge, roof, and soffit venting.

Protect Landscaping

Keep tree limbs pruned around structures. Position ladders, scaffolding, and roofing materials carefully when working to avoid plant damage. Repair any incidental scratches or holes in the roof.

Hire Professionals

Have licensed roofers do inspections and address any concerns beyond basic maintenance. They know best practices, have safety equipment for work at heights, and will not void manufacturer warranties.

Staying vigilant to perform basic roof care and promptly fixing problems will sustain performance for decades.

When Is Complete Roof Replacement Necessary?

There comes a point when repairs are insufficient, and a whole roof replacement is required. Typical red flags include:

Roof Age

Asphalt shingles last 15-30 years. Roof replacement is usually necessary once shingles are curling, cracked, or missing granules throughout 25% or more of the surface.

Frequent Leaks

Persistent leaks that reappear despite professional repairs indicate systemic deterioration. Severe leaks also risk mold, rot, and interior damage.

Storm Damage

Hail, falling branches, winds, or foot traffic can damage roof materials enough that repairs exceed replacing the whole roof.

Structure or Occupancy Changes

Significant building expansions, upper-level additions, or attic conversions change load requirements and may need roof structure upgrades concurrently with reroofing.

Replacing before acute failures occur avoids collateral injury like mold and rot. It also allows for planful upgrades like added insulation, solar panels, or architectural profile changes.


In summary, roofs are complex systems shielding what lies within. Their anatomy ranges from essential underpinnings to protective surfaces. 

Shape and composition considerations strive to meet structural loads, weather challenges, and aesthetic visions. 

With meticulous installation and proactive care, roofs reward structures and occupants with lasting shelter from the elements.

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