Roofing Terms 101

Glossary of Residential Roofing Terminology

Getting acquainted with roof-related vocabulary will help you better understand the Kairos Roofing procedures. Review the below terminology prior to – or after – we visit your home for your initial roofing consultation.

All-Weather Elastomeric Mastic

A pliable, elastomeric, asphaltic-based roofing mastic that can be installed in moist or wet conditions.

Asbestos

A natural, silicate and fibrous material.

Asphalt Felt
Felt saturated or coated in asphalt.

Asphalt, Roofing

A residual product of petroleum distillation ranging in color from dark-brown to black

Asphaltic
Treated with, or containing asphalt.

Backnailing

In addition to hot-mopping, fastening felts in a mechanical manner.

Base Flashing

The material that covers a cant strip, or transition, from the deck of the roof to a surface that is vertical.

Base Ply

The first ply (or lowermost) felt that is installed.

Base Sheet

Coated or saturated felt that is placed as the lowermost, fist ply while constructing a multi-ply roof membrane.

Bitumen

An asphalt-like material that is typically derived from petroleum or coal.

Bituminous

Something that is treated with, or contains bitumen.

Blister

An enclosed air pocket mixed with solvent vapor or water that is trapped in between two layers of felt, or resides between the substrate and the felts.

Blocking

Wood that is built into the roofing system, typically placed above the substrate, as well as around the penetrations and deck perimeter, acting as a nailer to attach the flashing or membrane and to create a termination option for the insulation.

Bond

The cohesive/adhesive forces that hold two components of the roof together.

Built-Up Roof Membrane

A semi-flexible, ongoing roof membrane assembled of coated/saturated felts and bitumen.

Cant Strip

A slanted strip of material that works to ease the space between the roof deck’s vertical projections.

Cap Flashing

A metal coping sheet fitted atop a higher wall, like a parapet.

Cap Sheet

The grainy membrane used as the top ply when building a roofing system.

Caulking

A flexible material used to fill joints and cracks, which can compensate for expansion for a period of time.

Coping

The weather-exposed, top-of-wall cover, which is typically sloped to rid water.

Counterflashing

A material usually made of metal that is installed vertically to cover the top edges of the base’s flashing.

Coverage

The surface area that is always occupied by a certain amount of particular material.

Crack

A fracture or separation in a type of material typically triggered by movement or stress.

Cricket

Also called a saddle or saddle flashing, a type of false roofing that is installed on horizontal roof valleys resulting from a certain projection, like chimneys, in order to deter water around the projection.

Deck

The structured surface where the insulation and roofing system are installed.

Drain

An apparatus that allows water to flow from an area of the roof.

Emergency Repair

A critical repair job that takes place during unfavorable weather conditions to halt the penetration of water from entering the home, which must then be replaced when the weather clears.

Envelope

The seal that is formed at the perimeter and penetrations by folding the base ply over the other plies in order to avoid any seepage of asphalt from the membrane’s edges.

Expansion Joint

Separating the roof deck or walls in order to account for movement.

Exposure

Any roofing material that remains exposed to the elements during inclement weather, or following the completed installation.

Fabric

A cloth woven from thread, filament or yarn of either organic or inorganic nature.

Felt

A sheet crafted by lacing flexible fibers through a blend of moisture, heat and mechanical work.

Felt Layer

An apparatus that is used to apply built-up roofing felts and bitumen.

Fiber Glass Felt

Fibers made of glass that are bonded into a resinous sheet ideal for the installment of bituminous waterproofing materials, roofing materials and roof shingles.

Flashing

A technique used to seal the roof membrane edges at the penetrations or perimeters.

Flashing Cement

A spreadable compound of reduced bitumen and mineral stabilizers that includes inorganic fibers, like asbestos.

Flat Asphalt

Always installed on dead-level decks, a type of asphalt that softens at a low temperature and flows when heated in the sun.

Insulation

A type of material that slows the movement of sound or heat.

Membrane

An ongoing, flexible or semi-flexible, open-weave fabric designated as the water control mechanism on a roofing system.

Mesh

A screen or wire with a metallic coating that reinforces concrete or stucco.

Modified Bitumen

A fused sheet made up of copolymer modified bitumen, which is often surfaced and reinforced.

Parapet Wall

Any wall portion that fully rests above the roof.

Permanent Repair

A type of repair that has been crafted to match the current roof system and is made to outlast neighboring materials.

Pitch

The steepness/slope of the roof.

Pitch Pocket

A metal sleeve placed around penetrations and filled with compounds like pourable sealer, mastic or bitumen.

Ply

One layer of felt in the built-up assembly of a roof membrane.

Polyester

An inorganic polymeric material that can be transformed into fibers and then used to reinforce fabrics and felts.

Pond

A part of the roofing that does not successfully drain water.

Primer

A thin substance of liquid bitumen added to the surface to encourage the adhesion of additional bituminous materials.

Rake

The sloped edge of a roof, as measured by the first and final rafter.

Re-Covering

The technique utilized when adding a new roofing system atop an existing roofing system.

Repair

A plan of action, along with the necessary materials, to stop water from entering a defective roofing system.

Restore

A plan of action, along with the necessary materials, to rejuvenate a roofing system in order to extend its current lifespan.

Slope
Also referred to as the pitch, the steepness of the roof determined by how many inches the roof rises for every foot of depth.