glossary

Acclimation – Allowing wood to adjust naturally to its environment until it reaches equilibrium moisture content (EMC).

Accoya – A modified wood created through acetylation, offering exceptional rot resistance, dimensional stability, and durability for exterior use.

Acrylic Coating – A water-based protective coating for decks, creating a durable, weather-resistant surface.

Adjustable Post Anchor – Hardware for positioning deck posts and elevating them off the footing to prevent water damage.

Air Dried – Wood dried naturally without kilns, reducing movement for certain hardwoods.

Alaskan Yellow Cedar – Pale yellow, naturally rot-resistant softwood valued for durability and fine grain.

Angled Decking – Deck boards installed at an angle to the joists for aesthetics or design patterns.

Apuleia leiocarpa (Garapa) – A high-density tropical hardwood from South America with golden tones and excellent durability.

Baluster (Spindle) – A vertical or horizontal element in a railing system, typically spaced ≤4" for safety.

Bamboo Decking – Engineered decking made from compressed bamboo fibers, durable and eco-friendly.

Batu – A durable tropical hardwood with a mahogany-like appearance and resistance to decay.

Beam (Girder) – A heavy horizontal framing member supporting joists.

Beam Pocket – A recessed area in a wall or masonry where a beam is seated.

Beam Span – The maximum distance a beam can span between supports without additional posts.

Beam Span Table – A reference chart showing the maximum allowable beam spans based on lumber size, species, and load conditions.

Black Locust – Extremely durable North American hardwood, naturally insect- and rot-resistant.

Blocking – Short pieces of lumber between joists or beams to add rigidity and prevent twisting.

Board Bender – A tool used to straighten bowed deck boards.

Bottom Rail – The lower horizontal member of a railing assembly supporting balusters or infill.

Box Sill – The framework of joists and headers at the perimeter of a deck.

Bracing (Cross Bracing) – Angled or X-shaped supports between posts or beams for stability.

Bridging – Short lumber pieces between joists to prevent twisting and increase strength.

Bull Nosing – A rounded edge on stair treads or top rails.

Butt Joint – Where the ends of two boards meet over a joist.

Cable Railing – Railing system using stainless steel cables for infill.

Caisson – A large cylindrical concrete foundation poured into a drilled hole below the frost line to support posts or columns.

Camber – A slight upward curve in a beam to prevent sagging.

Cant Strip – A beveled strip installed where a horizontal surface meets a vertical one, often used in waterproof deck membranes to ease the angle and improve durability.

Cantilever – A projecting beam or deck section supported only at one end.

Cap Rail – The topmost horizontal member of a railing system.

Capstock Decking – Composite decking with a protective outer layer for enhanced durability.

Cedar Decking – Naturally rot-resistant decking from cedar wood.

Closed Stringer – Stair stringer with solid sides hiding the treads and risers.

Composite Decking – A blend of wood fibers and plastic for low-maintenance decking.

Concrete Footing – A below-grade concrete base that transfers deck loads to the ground.

Cumaru – A dense, durable tropical hardwood ranging from yellow-brown to reddish-brown.

Cupping – Upward curling of deck board edges due to uneven moisture exposure.

Deck Blocks – Precast concrete supports for decks in frost-free areas.

Deck Footing – The structural base that supports deck posts.

Decking – The surface boards forming the walking area of a deck.

Decking Clip – Hidden fastener used to secure decking boards to joists.

Deflection – The amount a structural member bends under load.

Diamond Pier Footing – A precast concrete deck foundation system with angled steel pins driven into soil.

Douglas Fir – Strong, straight-grained softwood often used in framing and beams.

Drink Rail – A wide, flat top rail designed to hold drinks.

Drop Beam – A beam positioned below the joists rather than flush.

Eased Edge – A slightly rounded edge on deck boards to reduce splintering.

Eco-Friendly Decking – Decking made from sustainable or recycled materials.

End Grain – The exposed end of wood showing growth rings.

EPDM (Ethylene Propylene Diene Monomer) – A synthetic rubber membrane commonly used for waterproofing flat or low-slope roof decks and under-deck areas.

Equilibrium Moisture Content (EMC) – The moisture level where wood is in balance with its environment.

Expansion Gap – Space left between decking boards to allow for movement.

Face Screwing – Attaching deck boards by driving screws directly through the surface.

Fascia (Skirting) – Boards covering the ends of joists for a finished look.

Fascia Mount – Mounting railing posts to the side of the deck frame.

Flashing – Waterproof material that prevents water intrusion where a deck meets a structure.

Flashing Tape – Adhesive membrane applied to joists or beams to prevent rot.

Flush Beam – A beam installed level with joists for a uniform surface.

Footing Depth – The depth of a footing required for frost protection, per code.

Garapa – High-density hardwood with golden tones, naturally resistant to rot and insects.

Girder – Another term for a main supporting beam.

Glass Panel Railing – Railing with tempered glass infill for unobstructed views.

Glu-Lam Beam (Glued Laminated Timber) – A structural beam made from layers of lumber glued together for strength and stability, often used for long spans.

Grain Pattern – The natural lines and textures visible in wood.

Guardrail – A safety barrier along deck edges to prevent falls.

Handrail – A graspable rail for support, especially on stairs.

Header – A joist running perpendicular to other joists, supporting their ends.

Heartwood – The dense, inner portion of a tree, usually more rot-resistant.

Helical Pile – A steel screw-type foundation driven deep into the ground for stability.

Hem-Fir – Lumber from a mix of Western hemlock and fir species, often used for framing.

Hidden Fasteners – Systems that secure deck boards without visible screws or nails.

Ipe – Extremely dense tropical hardwood, also called Brazilian Walnut.

Jatoba (Brazilian Cherry) – A dense, reddish hardwood with high durability.

Joist Hanger – Metal connector that secures joists to beams, ledgers, or rim joists.

Joist Span – The maximum unsupported length a joist can span under load.

Joist Tape – A waterproof adhesive tape applied to the tops of joists to prevent moisture penetration and extend framing life.

Kerf Cut – A narrow saw cut used for bending or fitting boards.

Knee Brace – A diagonal support between posts and beams.

Lag Screw – A large screw for heavy-duty structural fastening.

Landing – A flat platform at the top, bottom, or between flights of stairs.

Lattice – Decorative framework, often used as skirting.

Ledger Board – A horizontal board attached to a building to support joists on one side.

Live Load – The weight a deck is designed to support from people, furniture, and temporary items.

Low-Clearance Deck – A deck less than 30" above the ground requiring extra ventilation.

Machiche – A dense tropical hardwood with chocolate brown tones, sustainably harvested.

Marine Grade Plywood – Plywood designed for moisture resistance.

Massaranduba (Brazilian Redwood) – A dense tropical hardwood with deep reddish tones.

Meranti – Southeast Asian hardwood used for decking and trim.

Miter Joint – A corner joint made by cutting boards at an angle.

Moisture Barrier – Material that prevents water intrusion into structural components.

Nominal Size – Standard lumber dimension before planing to final size.

On-Center (OC) – The measurement from the center of one framing member to the next.

Open Stringer – Stair stringer with notches visible along the treads.

Pergola – An open-framed structure providing partial shade.

Pier – A precast concrete support that rests on a footing or directly on the ground.

Picture Frame Border – A perimeter design using deck boards for a finished edge.

Pilot Hole – A small hole drilled before inserting a fastener.

Post – A vertical structural member supporting beams and framing.

Post Anchor – Hardware that secures posts to footings while keeping them elevated.

Post Cap – A decorative or protective covering for a post top.

Pressure-Treated Lumber – Wood treated with chemicals to resist decay and insects.

Purpleheart – A dense tropical hardwood with a natural purple hue.

Quartersawn Lumber – Boards cut perpendicular to growth rings for stability.

Railing System – The complete assembly of rails, posts, balusters, and infill.

Redwood – A naturally rot-resistant softwood with a reddish hue.

Riser – The vertical component between stair treads.

Rim Joist – The outermost joist capping the ends of the floor joists.

Sapwood – The lighter, softer wood near a tree’s bark.

Screw Gun – A power tool for driving screws.

Scribing – Fitting a board to match an irregular shape.

Shake – A split in wood along the grain.

Snow Load – The additional load a deck must support from accumulated snow, determined by building codes and climate data.

Softwood – Wood from coniferous trees, generally less dense than hardwoods.

Sonotube – A cardboard form used to shape poured concrete footings.

Southern Yellow Pine (SYP) – Strong, common structural lumber often pressure-treated.

Spruce-Pine-Fir (SPF) – Economical framing lumber used in substructures.

Stair Stringer – A diagonal framing member supporting treads and risers.

Stringer Spacing – The distance between stair stringers for proper support.

T&G (Tongue and Groove) – A joint where a protruding “tongue” fits into a matching “groove.”

Teak – A durable tropical hardwood, golden-brown, highly resistant to decay.

Thermally Modified Wood – Heat-treated to improve stability and decay resistance.

Tigerwood – Exotic hardwood with distinctive dark striping.

Tread – The horizontal surface of a stair step.

Treated Micronized Copper Azole (MCA) – A modern preservative for pressure-treated lumber.

Tropical Hardwoods – Dense woods grown in tropical climates, prized for durability.

Under-Deck Ceiling – A water-diversion system installed under a deck.

UV Protector – Coating that shields wood from UV damage.

Ventilation – Allowing airflow under/around a deck to reduce moisture buildup.

Vinyl Decking – Low-maintenance decking made from vinyl.

Warp – Distortion in wood from uneven drying or exposure.

Western Red Cedar – Lightweight, aromatic, naturally decay-resistant softwood.

Winder Step – A stair step wider on one side, used to change direction.

Zero-Maintenance Decking – Materials like composites or PVC that require minimal upkeep.