Dave's Construction Dictionary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
A thickness of decking material between 1x6 and 2x6. Although it is called 5/4x6, it is actually 1" thick and 5 1/2" wide. Likewise, a 1x6 is really 3/4" thick and a 2x6 is 1 1/2" thick.
The crushed rock and sand of a concrete mix.
A bolt embedded in concrete used to hold structural members in place. In residential construction 1/2"x6" or 8" anchor bolts, as shown, are used to hold down the sill plate
for floor joists
or the bottom plate
A vertical molding attached to the meeting edge on one door of a pair of doors to seal the gap between them.
A window where the sash swings on its horizontal top edge so it can swing out.
A rounded or square spindle
attached vertically between bottom and top rail or tread and top rail of a guard or handrail.
A unit of handrail system comprising the rails and balusters
The exterior finish nailed to the side of the end rafter
of a gable
See Foundation Plan
A temporary framework used to assist in locating the corners when laying out a foundation or excavation. For more info see article The Foundation
A framing structural member used to support a series of joists
, in place of a continuous wall.
A bending rail is a handrail made up of strips of wood that can be glued together and bent around a curve. The bent pieces are then taken to be milled after they dry.
A rigid framework usually pre-fabricated, placed in a series across the length of a structure to support the main members. Used in bridges, trestles and the like.
See Seat Cut
It is common for building supply retailers to charge large volumes of lumber to their contractor customers calculated in Board Feet also know as FBM (Foot/Feet Board Measure). A board foot is 1 foot wide by 1 foot long by 1 inch thick, that is a 1x12 that is 1 foot long is equal to 1 FBM. A 2x12 one foot long is equal to 2 board feet or 2 Feet Board Measure. Usually, the store has their dimension lumber priced in units of 1000 board feet or MFBM and charges the contractor accordingly. Our handy converter
can help you convert your dimension lumber to board feet.
A framing member to help support the ends of a row of joists
, which is attached to them at right angles. Also known as a rim joist.
Pieces of 2x2 or metal crossed or solid blocks the same width as the joists
, installed between joists at the center of their span. Bridging should be installed at no more that 7' apart, between each support or other bridging.
A very large concrete float
with long handles, used to float a large slab.
An official list of rules that a building or construction site is legally obliged to follow. Building Codes are generally state, province or country wide but local governments can add their own rules. The rules in Building Codes are generally well thought out and have a practical reason behind them. Even if there is no legal obligation for someone to follow Building Codes, it is still a very good idea to know and use them. (For more info see The National Building Code
The two pieces of a joint are simply butted together (end to end) without an overlap.
A strip of lumber ripped to form a 45 degree surface. Also known as chamfer strip when used in forms to leave an edge chamfered.
Lumber or molding above another to hide end grain or provide protection or finishing.
A bolt with a round head and square shoulder. The square shoulder gets pulled into the hole and keeps the bolt from turning when the nut is being tightened. The round head doesn't need a washer, has no edges to scrape or catch things and gives a finished look.
A window where the sash swings on its vertical edge so it can swing in or out
A strip of plywood or lumber to support a shelf or fixture. Also used to strengthen a door, etc or to add to its dimension.
Also called a collar beam
or collar brace
A horizontal member used to provide intermediate support for opposite roof rafters
, usually located at the upper third of the rafter to decrease its span.
This comes from describing the face of the board, which looks like someone took a comb to it and left small ridges and valleys in the surface.
A nail with a head used in framing, referred to as a common bright nail.
One of a series of rafters
extending from the top of an exterior wall to the ridge of a roof.
A tool used in the first stage of finishing concrete to bring the laitance to the surface and knock the aggregate just below the surface.
To float - the act of using a tool to start the finishing process.
To cut or shape the end of a molding so it will cover and fit the contour of an adjoining piece of molding. For more info see my article How to Cope an Inside Corner
A bit to create a round tapered or coned shape hole to match the shape of a flat head screw to set it flush with or below the surface of the material being fastened.
A low space under a floor of a building, which lets workers access wiring or plumbing.
See: laitance, concrete
Also called a jack stud
. A vertical member that supports the header
in an opening of a bearing or supporting wall.
Almost every board is curved slightly. The crown is the top of the curve of a board.
A rectangular groove in a board.
Lumber in standard dimensions, such as, 1x4, 1x6, 2x4, 2x6, etc.
A suite operated as a housekeeping unit, used or intended to be used as a domicile by one or more persons and usually containing cooking, eating, living, sleeping and sanitary facilities.
The lower, level part of a roof overhanging a wall.
An Elevation is the view of the side of the house or a wall in a room as if the viewer is standing back and looking straight at it. This drawing shows each side of the house including the foundation and roof. It shows the configuration of the windows (sliding, casement, awnings, etc.), the outside doors, handrails, gutters, the pitch and overhang of the roof, the siding, roofing, and any chimneys. Usually the dimensions are left off, but the drawing is to the scale
noted. This drawing is used to determine the shape and openings of windows, with bathroom windows noted as obscure, the look of the exterior doors, and the shape of the roof. The height of the house can easily be determined, as well.
A structural member which is designed by a Professional Structural Engineer used in spans greater than that allowed by standard building codes
. These members come with specifications for fastening them together, notching and drilling holes, bearing surfaces required and assembly.
Wood products that are manufactured to precise national and international standards by binding together wood strands, fibers, or veneers with adhesives. These include plywood
, particle board
and structural I-beams. Engineered wood is used instead of dimensioned lumber
. Often made with rye straw, wheat straw or sugar cane rind, instead of wood.
The frame of a set of cabinets fastened perpendicular to the gables
of the cabinets on which the doors are hinged. The face frame is made up of the stiles
Nailing through the face of a board, as opposed to nailing through the spline of a board or toe nailing
on an angle.
The trim piece nailed to the ends of a series of rafters
to tie them together at the lower, level end of a roof. The fascia supports the sheathing on the edge of the roof as well as the front edge of the soffit
The exterior finish nailed to the fascia that is nailed to the rafter
ends that runs horizontally around the roof on which the gutters are mounted. The fascia board forms a drip edge for rain water, as well as hides the end of the roof sheathing and soffits
This drawing shows each floor of the house (main, second, etc.) and indicates the floor or ceiling joists
above it or the recommended truss
layout. It should show the layout of the kitchen cabinets along with the appliances and cabinets. It will show the exterior wall and interior partitions and any stair layout. It also may show the layout of the switches and lights and plugs, as well as hose bibs, plumbing fixtures and heating ducts. This drawing may refer you to a Section or Cross Section
it wants to detail and the direction it is looking at in the section. This is shown on the plan in a circle with a point on it. Inside the circle is the letter of the section and the page on which to find it. The point or arrow on the circle refers to the direction the viewer is looking from. The circle is attached to a line which cuts the drawing along a certain part to depict the internal section of that part.
Having ends or surfaces that are even.
The spreading course at the base of a foundation wall, pier or column. Usually a concrete footing for an 8" wall is 16" wide by 6" deep. For more info see article The Concrete Foundation
A circular wood bit having outer cutters with a very short center point, for drilling shallow holes.
Also called a Basement Plan
. This drawing is a plan
view of the foundation walls and slab. It also shows the floor joists
above it, their size and direction, shown by arrows.
See Steel Square
Stands for "Good One Side". This is a quality of plywood that has one of its sides smooth enough to look good when painted or wallpapered. It would be used where only its good side will be visible.
Stands for "Good Both Sides". This is a quality of plywood that has both of its sides smooth enough to look good when painted or wallpapered. It's more expensive than G1S and so is used only where both sides of the plywood will be visible.
1. House framing: The upper triangular-shaped portion of the end wall of a house.
2. Cabinetry: The structural framing member used to partition off each compartment in a set of cabinets.
The entire end wall of a house formed from the pitch of the roof.
The end truss
in a roof system that caps the end wall. If the overhang is more than 16", the gable truss is lowered by 3 1/2" to allow for 2x4's to be cantilevered over this truss and nailed into the adjoining one to form the overhang.
A nail covered with a zinc coating to resist rusting in damp conditions. A nail lacking this coating is referred to as bright.
A heavier joist
that carries other joists in a floor or roof system.
See Laminated Veneer Lumber
Short for (Glued Laminated Timber). An engineered wood
made of several layers of small-sized dimensioned lumber
glued together into a single, large, strong, structural member that can be used as a column or beam.
A panel or bracket of wood or metal fastened to the intersections of members or at corners to provide strength and stiffness.
A horizontal structural member that supports the load over a window or door opening. Also known as a lintel
The thickness of the rafter or truss vertically above the seat cut or bearing surface on the wall.
The sloping ridge of a roof formed by two intersecting roof slopes.
which forms the hip of the roof. It is usually made from a board that is the next size larger in width than the common rafters
(for example, if the common rafters are 2x6's, the hip rafter is a 2x8).
structural floor or roof joist
consisting of a top and bottom chord of dimension lumber
and a web of oriented strand board
. Also known as Silent Floor.
There are two types of jack rafters: the hip jack
and the valley jack
. The hip jack
is a short rafter
that spans from the wall plate to a hip rafter
. The valley jack
goes from a valley rafter
to the roof ridge
The frame or lining of a doorway, window or other opening.
Molding used for trim that is in the shape of the letter J, used to trim the edge of drywall, plywood and vinyl siding.
One of a group of structural members designed to support a floor or ceiling load. When the member supports a ceiling as well as a roof it is called a roof joist.
A steel section shaped like a stirrup, which is specially bent so it can be fastened to a beam in order to provide end support for joists
A regional district, county or city which interprets and enforces the National Building Code
in their area.
A key is a term used when pouring fresh concrete onto an existing footing
or wall. A channel is formed before the first pour is set either by embedding a 2x4 ripped
to form a slight taper (for easy removal) or scraping out a channel in the concrete with a tool. When the concrete has set, the 2x4 is removed leaving a channel in which the fresh concrete can flow. This creates a bond between the two pours and prevents lateral movement.
A short wall to help support a row of rafters
or roof joists
A bolt with a wood screw thread rather than a machine thread, in common diameters of 1/4" to 5/8".
Also called: cream
The cream or paste of the concrete which rises to the top of the mix when floated. For a photo of this being washed off an exposed aggregate driveway, see Concrete Work 1: Exposed Aggregate Driveway
(second photo from bottom).
A structural member attached to vertical framing to support joists
or other horizontal framing. Also called a ribbon board or strip.
A strip of lumber, plywood or fiberboard to add support to a shelf, top or bottom in a set of cabinets.
A cable, rope, string, cord, or wire.
A horizontal structural member that supports the load over a window or door opening. Also known as a header.
Stands for (Laminated Strand Lumber). An engineered wood
used for a stud
or rim board
. Also known as TimberStrand.
Stands for (Laminated Veneer Lumber). An engineered wood
used for a beam
. These usually come in widths of 1 3/4" up to lengths of 60'. Also known as Gang-Lam and Micro=Lam.
Stands for (Medium-Density Fibreboard). An engineered wood
made from softwood fibers that were mechanically separated, then randomly combined, glued and pressed so the material has no grain, but is consistent throughout. It swells if wet unless treated.
See Laminated Veneer Lumber
A joint formed by cutting and butting two pieces of board together so that each board has the same angle and same length of joint line between them. The process of making a miter joint.
A punch used to drive in the head of a nail so it's slightly below or level with a surface. If you just have one or two nails to set, another nail turned upside down can substitute for a nail set. But, be careful the upturned nail doesn't slide off the nail you're trying to set and make a larger hole.
The post to which a railing or balustrade
The part of the step that sticks out past the riser
An S-shaped curve or an arch formed of two S-shaped curves meeting at the top of the arch.
Stands for (Oriented Strand Board). An engineered wood
made of thin strips of wood (about 1"x6" lengthwise grain) cross-oriented, glued and pressed together. Commonly used to sheath walls, floors and roofs. Also used for the web in I-Joists
A fence board or picket, also used for deck handrails.
See PSL (Parallel Strand Lumber)
An engineered wood
made of particles (wood chips, shavings and saw dust), glued and pressed tightly together so it is dense, heavy and flat. It is cheaper, weaker and less durable than wood or plywood
and harder on your saw blades. It swells if wet.
A type of small pea sized round rock in a concrete mix used in exposed aggregate finish.
A concrete post or column.
Pitch of a Roof
See Rise (2)
Also called bird's eye view
. The view you see when you look straight down at something.
Also called blueprints
. A set of plans consists of drawings showing different views of the house from different perspectives. The term "plan"
is used to designate a bird's eye view. The viewer is above the house looking down at it. Plan views include the Plot Plan
, the Foundation Plan
, the Floor Plan
, and the Roof Plan. In some sets of plans we can come across a Reflected Ceiling Plan, which shows the ceiling as if laying on your back looking up, rather than flying above it and looking down. A set of plans usually is not limited to plan views. It should include Elevations and Sections. An Elevation is the view of the side of the house or a wall in a room as if the viewer is standing back and looking straight at it. A Section is a drawing of the internal aspects of a wall or floor, etc. as if the viewer cut the wall or floor in two with a knife to see what it is made of. Common to each drawing in a set of plans is the Scale. To fit the size of the house on a sheet of paper the drawing is reduced in size. This reduction is known as the scale of the drawing. Most drawings in a set of house plans show - Scale: 1/4" = 1'-0". This means that every 1/4" on the drawing represents 1 foot on the house or 1/48th scale.
Any of the following:
: A horizontal member placed on a wall and supported on studs
to carry the trusses
of a roof or the joists
of a floor.
The double plate
is nailed on this top plate to facilitate overlapping of joints of the top plate at corners and intersections. For picture click here
: A horizontal member on which the studs of a wall sit, providing a means of attachment to the foundation or floor.
: A bottom plate attached to the foundation.
A machine with a vibrating plate, rather than wheels or drums, to compact the ground before pouring concrete.
A line scribed
or marked on a rafter
that corresponds to the outside face of the wall.
This is a plan
view showing the building envelope (the perimeter of the house) in relation to the lot's boundaries. It should have the shape and outside dimensions of the house and lot, the location of the driveway, and the set backs of the house to the lot lines. The Plot Plan may have height elevations at the corners of the house and lot, as well as a geographic direction indicator: north, south-west, etc. The scale may be a bit smaller than other plan views (Scale: 1/8" = 1'-0").
Vertical, straight up and down. (See following)
A weight that has a string connected to the center of its top. It's used mostly to ensure that a wall being constructed is perfectly vertical. It can also be used to get an exact measurement of a spot directly below whatever it is hanging down from. Example: hang a plumb bob from a ceiling fixture and measure from the bob to the wall to get the exact distance the fixture is from that wall.
The cut at either end of a rafter. The rafter is on a slope and the cut is vertical or plumb.
An engineered wood
made of glued layers of veneer (ply) arranged so each layer's grain is at 90 degrees to the previous ply.
A short wall sometimes used to help support rafters
, shortening its span. As a pony is a short horse, so is a pony wall a short wall.
A vertical structural member designed to support a beam
A formed metal plate, which is embedded into concrete, used to hold the bottom of a post
Wood that has been soaked in a preservative solution under pressure making it highly resistant to rot or insects and therefore suitable to long-term outside use.
Stands for (Parallel Strand Lumber). An engineered wood
used for columns, headers
. These come in thicknesses from 2 11/16" to 7". Also known as Parallam.
Also spelled: Purline. One of several horizontal timbers supporting the rafters of a roof.
A groove cut in the surface along the edge of a board. A rabbet is a dado
cut along the edge of a board leaving one side of the rabbet open.
The slanting boards that give the roof its slope and support. They are like wall studs
except they are slanted for the roof.
The horizontal members of the face frame
of a set of cabinets.
The edge of a sloped roof forming the overhang beyond the wall of a gable
roof or other sloped roof.
Reinforcing steel bars used in concrete to enable the concrete to take on the properties of steel.
Reflected Ceiling Plan
A reflected ceiling plan shows the ceiling as if you were laying on your back looking up, rather than the usual plan
view, which is flying above it and looking down.
Also called r-value
Resistance factor or value. R is resistance to heat loss in given materials. A good insulation material has a high R-value
A board or length of boards nailed to wall studs with the purpose of supporting ceiling joists
nailed to the ribbon.
See Ledger Board
The board that runs along the top edge of all the rafters
of a roof and holds them in place. (For picture see plumb cut
The box joist
usually tying together engineered I-Joists
around their perimeter. This board keeps the joists
vertical at the exterior wall line to prevent the joists from leaning over and loosing their effectiveness..
See Box Joist
To saw a board or plywood in the same direction as the grain of the wood. To cut a board, on the other hand, refers to cutting it across the grain. Although plywood is made up of layers of veneer, each placed with the direction of its grain perpendicular to the layer below it, plywood does have grain. We refer to the top and bottom veneers when we talk about the grain of plywood. These outside veneers are what chip if we use a ripping saw for cross cutting. A ripping blade is different than a cross cut blade. A rip blade has teeth like chisels-flat across-where a cross cut blade has pointed teeth to cut the grain. Nowadays we use combination blades that do both, hence the name. That's why, before the days of power saws, a carpenter had both a rip saw and a crosscut saw.
1) The height of one stair
in a staircase. This is the amount of vertical distance someone moves when he or she steps from one stair onto the next. Per most Building Codes
, the rise should be between 5 inches and 7 7/8 inches with the ideal rise for a residence being 7 inches.
2) With a roof
, the rise is the vertical distance between the top of a section of roof and its lower edge. The section being measured always has a run (horizontal distance) of one foot (12"). The rise is used with the run to describe the pitch of the roof, for example if the roof rises 5" with each foot of run, it's called a 5 and 12 pitch. If the roof rises 7" with each foot of run, it's called a 7 and 12 roof.
The vertical part of the stair between a tread and the underside of the tread above it.
1) With stairs
The horizontal distance of one stair in a staircase. It is how far "in" the stair goes which gives the amount of room for someone's foot as he or she climbs the stairs. Per most Building Codes
, the run should be between 8 1/4 inches and 14 inches. An intermediate run is 11 inches. See tread
for comparison to run.
2) With a roof
, the run is the horizontal distance of a section of roof, compared to the rise, which is the vertical distance of that same section. When measuring the pitch of a roof the run is one foot. See also rise
Stands for "Surfaced One Side Two Edges". This is a board, usually cedar, with both edges smooth and one side smooth. The remaining side is rough and this side is usually considered the good side, the side that's showing.
Stands for "Surfaced Four Sides". This is a board that is smooth on all sides. This usually applies to finishing boards such as fir, pine, oak, maple, etc.
A small piece of plywood or lumber, which is fastened over a joint to keep it rigid.
Scale of a Plan
Common to each drawing in a set of plans
is the Scale. To fit the size of the house on a sheet of paper the drawing is reduced in size. This reduction is known as the scale of the drawing. Most drawings in a set of house plans show - Scale: 1/4" = 1'-0". This means that every 1/4" on the drawing represents 1 foot on the house or 1/48th scale.
To draw a line an equal distance from a reference surface onto another surface by using a scriber (looks like a compass) or a block of wood as a guide.
Also called a bird's mouth
This is a notch cut in each rafter
where the bottom part of the rafter rests on the top of the wall. Without this notch,
there would be only a tip of the bottom edge of the rafter touching the top of the wall. The seat cut gives a broader surface to nail the rafter to the top of the wall and it also helps prevent the walls from spreading out from the weight of the roof.
Also called a Cross Section
. A Section is a drawing of the internal aspects of a wall or floor, etc. as if the viewer cut the wall or floor in two with a knife to see what it is made of. Any drawing may refer you to a Section or Cross Section it wants to detail and the direction it is looking at in the section. This is shown on the plan in a circle with a point on it. Inside the circle is the letter of the section and the page on which to find it. The point or arrow on the circle refers to the direction the viewer is looking from. The circle is attached to a line which cuts the drawing along a certain part to depict the internal section of that part.
A grade of plywood that has solid knots on the top veneer.
To drive a nail so the top of its head is level with or just below the surface of the material the nail is embedded in. The nail is usually punched in with a nail set
but, in a pinch, another nail turned upside down can be used as a nail set.
A shim is a thin wedge that can be placed between two surfaces to tightly fill a gap, as between a door jamb
and a cripple
The lowest horizontal member of the frame of a structure resting on the foundation and supporting floor joists
. Also refers to the lowest part of a window or exterior door frame.
See Plot Plan
Snap a Line
Pull out the string in a chalk reel, hold the string taut with both ends on the markings you've made where the line is to go, pull the center of the string away from the material and release it so it snaps against the surface and leaves a trail of chalk, which is called a snap line.
The underside of elements of a building, such as overhangs, staircases and beams.
A cardboard tube used as the form when pouring concrete columns.
A block of wood between members.
Span of a Roof
This is the entire horizontal distance across that a roof covers. This is usually twice the total run for a gable roof. There are factors where this is not the case, such as a shed roof or an unequally pitched gable roof.
The turned round or square vertical member of a handrail system.
The slope of a skylight tunnel expanded to allow more light to come in.
Having corners that are like a square (90 degrees).
These are little thumb screw clamps that you attach to the steel square
(framing square) right at the point of your rise
measurements. With these installed
on the square you simply slide the square along the stringer
rather than having to look at the measurements for every move down the stringer.
The finish trim against the wall and a set of stairs.
with a stop
that is rabbeted
out rather than a piece of wood nailed in the center of the jamb to act as a stop.
Also called a framing square
. Used by carpenters to measure stair stringers and roof rafters.
(how to use
Stands for "Select Tight Knot". This is a board that has knots in it but the knots are tight rather than loose. Select means it's the best grade.
The vertical member of the face frame
of a set of cabinets.
Door Stop. The thin board or part of the jamb
that stops the door from swinging past the jamb when closing the door.
Applying material across the length of structural material. Strapping a joist
is nailing a 1x4 at the bottom of the joist in the middle of its span tying the joists together and preventing them from twisting over and collapsing with a load. Strapping a truss
is nailing a 1x4 at the top of the bottom chord or across its webs to keep the truss plumb, the spacing accurate and the trusses
tied together as a unit. Strapping a joist or truss should be continuous with its ends fastened to a sill
Strapping Concrete Walls
To apply boards to the concrete wall to allow drywall or panelling or whatever to be attached. Strapping the walls with 2x4's on edge allows you to insulate the walls before applying drywall, etc.
A stair stringer is one of the boards that hold each step in place. They run the length of a straight set of stairs (see Figure 1). For more info see (How to Cut a Stair Stringer
See Ledger Board
A support attached to the top of ceiling joists
to strengthen them, maintain spacing and keep them at the same level.
A vertical support member giving most of the strength to walls. These are usually 2x4s spaced 16" apart that wallboard (drywall mostly) is attached to.
Boards or sheet material laid on joists
under a finish floor.
To nail on a board but leaving the head of the nail out far enough to be able to pull it out if the board later needs to be moved.
The plumb cut
at the bottom end of a rafter.
Also called a reducer
. A strip of metal, wood or other material, beveled on each edge and used at the junction of two different floor finishes under doors, or on top of the door sill
at exterior doors.
See Laminated Strand Lumber
A nail inserted at an angle into the side of a board to ensure it penetrates into a second board. This is usually done where the first board is too thick to give enough penetration when nailed through the face.
Tongue and Groove
A means of facilitating a joint with a dado
in one piece and a spline in the other, which fits into the dado, referred to as matched.
1) With stairs
: The total height of a staircase which extends from the lower level up to the surface of the upper level. A staircase built from one floor up to another floor has a total rise of exactly one storey.
2) With a roof
: the total rise is the vertical distance from the top of the roof to the top of the walls.
1) With stairs
: the total run is the horizontal distance from a plumb bob
hanging from the top of a staircase to the edge of its bottom step. It's the length of the floor space that is under a staircase.
2) With a roof
: the total run is the horizontal distance from a plumb bob,
hanging from the top of a roof, to the exterior wall. On typical roofs, the top of the roof is in the center of the building and the roof slopes down to the sides of the house with both sides of the roof having the same amount of slope. In this typical case, the total run of the roof is half the span, which is the entire horizontal distance from one side of the roof to the other at the top of the outside walls.
1) The horizontal distance of one stair in a staircase. It is the run
plus the nosing
. Per most Building Codes
, the tread should be between 9 1/4 inches and 14 inches. An intermediate tread is 12 inches.
2) The horizontal structural part of the stair or step. The part you walk (tread) on.
A structural unit made up of crosspieces to provide support, over large spans, for a roof or bridge. A truss is designed to give the most lift using the least amount of material so its own weight is minimized.
The matched edges, usually tongue and groove
, of boards forming a v-shape when assembled.
that are located at the center of roof valleys to support the jack rafters
and the sheathing.
The ceiling area of a house that follows the line of the roof or is shaped as an arch.
The structural members of a truss
that connect the top and bottom chords.