Common Carpentry Terms you may come across on the building site and what they mean
What does 'plumb' mean? What is a 'router'!?
Below is a a list of Carpentry Terms, a 'carpentry dictionary', full of words you may come across on site or in the hardware shop that you don't know the meaning of. Each has a brief explanation and a link to a page with more detail if there is one on this site. You can click on a letter below to jump straight down to its corresponding section to save time.
Carpentry Terms beginning with A
A substance for sticking two materials together by surface attachment. PVA, gripfill, contact adhesive for example
Timber that has been stacked and dried naturally by exposure to air.
A hexagon and L shaped key, available in metric or imperial sizes. Used for tightening 'Allen' screws/nuts bolts
A motif or carving/molding that has been worked separately and then applied, rather than being cut/fashioned in situ.
Timber around the bulkhead of a staircase that hides the face of the joist/trimmer and is underneath the spindles, base-rail and nosing is called an 'apron' or apron lining. To see a picture, click here.
The spindle or shaft on a machine that turns blades or other cutting wheels.
Architraves are the decorative moulding installed around door frames to cover where the lining meets the wall. Also known as 'door casing'. Click above for more tips on fitting architraves and areas of their use.
Architrave blocks are decorative mouldings that can be installed in place of a mitred corner when installing architraves. They can also be used elsewhere to enhance your trim carpentry work, click the link above to see a few examples.
Pointed instrument with a handle useful for starting nails or screws or positions when setting out a project.
Carpentry Terms beginning with B
Barge boards are those attached to the outer common rafters on a gable roof. Where they meet with the fascia and Soffit boards a box end is formed. To see a picture, click here.
A decorative molding used either for the enhancement of detail or to cover a join between two surfaces like plaster and timber for example.
Pegs which are placed into holes in the workbench that work with the vise to hold wide material firmly in place.
Tool with a cutter that protrudes from the face when pushed up against timber and cuts a small oval slot. Cuts are made in two pieces of timber that are being joined together. An oval shaped timber disk (biscuit) can then be glued and inserted in the slots where it swells to form a tight bond.
Quite often during finishing or trim carpentry and when fitting fascias for example angles need to 'bisected', or halved. Go to the bisect an angle page for more information.
A small plane designed primarily for cutting across end grain, but useful for many other applications (see also hand plane).
Timber that bends out of shape along its length has a 'bow' or is bowed.
A hand drill with a cranked shape handle with a flat knob on the end, special auger bits with a square tapered shank fit into a two jaw chuck. Replaced by cordless/battery drills.
An end to end joint between two pieces of timber.
Carpentry Terms beginning with C
An measuring/marking/checking tool with two legs, one of them sliding, looks a bit like a compass.
Blades/cutters/drill bits etc with extremely reinforced cutting edges. They are good for drilling various masonry materials.
Framing carpentry or first fix carpentry is also known as 'carcassing' work.
Much wider than a normal pencil and rectangular in shape. Click above for more info.
Bevel on the corner of a board at a 45° angle. Also a stop chamfer, that stops and starts a distance in from the end. Go to the page about Skirting to see chamfered skirting boards being fitted.
The chuck will hold a drill bit or router cutter that will be spinning in the tool. Two examples are lathe & drill chucks.
Is a portable handheld powered saw great for everything from cutting intricate cabinetry work, ripping down timber, cross cutting and even cutting a whole roof!
A collar beam is a type of roof timber that is used to stop the rafters from spreading. Fixed horizontally to rom the bottom of a triangle, with a seat cut angle cut on each end, it is usually bolted for strength. If the rafters are long, they may have joists at the bottom to keep the bottoms from spreading, and collars bolted higher up to do the same job.
Another type of chuck that Routers use. It accepts a certain size of cutter, the most common for site use being ¼ and ½ inch.
A combination square is a hand tool used for setting out and marking the work-piece. A square with an adjustable ruler that can mark both 90 and 45 degree angles (see also 'square').
An adjustable setting out tool used for drawing circles and Scribing timber to irregular surfaces. Consisting of two legs joined at a pivot hinge, one has a point the other holds a pencil.
A common place to find a compound angle or cut is a jack or creeper rafter that is used for a hip roof. When timber is cut at two angles, one to the face and one to the edge it is referred to as a compound miter.
A drill bit that bores a pointed hole allowing a screw head to sit flush inside the face of the material, or below the surface so it can be plugged with filler or a wooden pellet and decorated over. Helps to avoid splitting the timber when fixing.
A cut which runs across the grain of the timber.
Happens when the edges of the board bend with the grain, away from the center to form a concave shape. Keeping timber dry stacked properly helps to avoid this problem.
Carpentry Terms beginning with D
Decorative molding found mainly in period style buildings. Runs around the room around a metre off the floor.
A right angle joint where the fingers are shaped like a doves tail. Can be cut by hand or with a dovetail jig and router. Used commonly on furniture and drawers for example.
A straight round wooden peg used to align and hold timber together in a mortice and tenon joint, 'drawer dowels'. Used commonly on staircase to hold newel posts to stair strings.
Metal punch that goes into the pre-drilled dowel hole to mark where to drill the second piece.
One of the carpentry terms heard more in the joinery shop than on site, it means the finished size of timber after being machined/planed.
Carpentry Terms beginning with E
A really strong glue often consisting of two parts that glues practically anything!
Calculating how much materials are required, cost and pricing up work is called estimating.
Carpentry Terms beginning with F
Surface of finished timber that will be most visible, you tend to work and set out measurements from the face.
Fascia and soffit boards are those attached to the bottom of the roof structure to form the eaves and to fix the gutters too.
Pieces of wood with fingers used to press material being machined against a fence and or down against the table. Used on a router/table-saw for example.
Adjustable straight guide used on table saw or router table for example to push the material against in order to maintain a parallel cut to the blade or cutter.
Substance used to fill nail holes or irregularities in the surface of material before applying a finishing coat.
Tapered square fingers used to join material length ways, often used in manufacturing moulding to join short lengths together and minimise waste.
After the framing carpenters and the plasterers have done their bit and the finish or trim carpentry work can start. All the jobs that will be seen by the client from doors to kitchens fall under trim carpentry. Click above for more info and step by step guides.
The floor to floor is another term used to describe the total rise of a staircase. Divided by the number of 'risers' will give you the total height of each step on the staircase. The floor to floor measurement is a directly vertical measurement from one floor to another, which you can see a diagram of at the staircase page.
When two adjoining surfaces are joined perfectly flat to each other they are flush. Otherwise one is 'proud' and the other 'shy'.
Structural carpentry work like timber framed houses, walls, roofing and floor joists for example all fall under framing carpentry.
A saw machine with a very fine blade used for delicate cuts, in thin material.
Type of drill bit that has a center spur and circular rims with cutting teeth that is used to cut clean flat bottomed holes. I use a 50mm forstner bit when drilling newel bases and installing newel posts.
Carpentry Terms beginning with G
The fibres of the wood and their direction are known as the grain.
Some common terms you'll hear that refer to the grain and its direction are:
'Crosscut' - Cutting across the grain
'ripsaw' - Cuts in line with the grain
'Against the grain' - For a smooth finish and to prevent tearing always plane or pare (chisel) in the same direction as the grain, its the same principle as shaving your face!
The term 'Green' means fresh, and refers to timber that has not yet sufficiently dried. Green Oak, for example.
If you hear the term 'grit' it could be in relation to either sandpaper or a sharpening oil stone. Typically the more 'grit' the finer the abrasiveness. 40 grit sandpaper is very rough, 120 grit is fairly fine.
Term used in staircase and roofing construction. With stairs, the going means the total distance horizontally the staircase will travel. In roofing, the going is the total distance each rafter will travel, which normally equates to the total span minus the thickness of the ridge and then divided by two (see also rafter lengths).
Carpentry Terms beginning with H
Hand planes are used for smoothing out and flattening the rough or uneven surface of timber, and reducing the thickness. When using a plane always go 'with the grain'. This is the same principal as shaving your face, planing against the grain can result in 'tearing' instead of cleanly cutting the timber. There are lots of different types of hand planes, click above for more information and tips on sharpening them.
Hardboard is a strong, smooth sided and flexible sheet material also known as high density fibreboard. Apart from using it as a sheet material it's also good for protecting new floors or work surfaces when work is being carried out around them.
Not necessarily referring to the hardness of the wood itself, hardwoods are not like softwoods which come from conifer trees. They are usually 'broad leaved' and deciduous. Typical examples commonly used in carpentry and joinery include Oak, Mahogany, Walnut, Teak and Idigbo
Commonly made of steel or brass, hinges are mechanical devices that allow two objects to pivot on each other. Typically used on doors, windows, gates etc. Click here to go to a page with tips for fitting hinges.
Carpentry Terms I
An I-beam is a type of steel used in construction. As a carpenter you often need to fit timber into the 'web' of the steel to provide a fixing for sheet materials or as something to fix joists into.
Carpentry Terms beginning with J
An aid used to clamp a work-piece or act as a guide when performing repeat cuts in manufacturing or assembling. Common carpentry jigs available are worktop, hinge and letter-plate jigs.
A jigsaw is a power tool that is fitted with a small straight blade that moves up and down in order to cut. Can be used to cut circular and other intricate shapes. Click above for more information and tips on using jigsaws, or here for help choosing the right blades.
u>Carpentry Terms beginning with K
Kick back occurs when a tool such as a table saw throws the work-piece back towards the operator. It can happen because the timber pinches the blade or the person feeding the timber moves it in the wrong direction. Most tools these days are fitted with anti kickback devices.
A heated chamber a bit like a large oven for drying timber. The air flow, temperature and humidity are controlled.
Timber that has been dried in a kiln.
Knots are the roots of twigs and branches found in timber and are tougher than the rest of the wood for that reason. 'Knotting' should be applied to all knots before painting to prevent resin seeping through after decorating.
Carpentry Terms beginning with L
(Man made) Laminated materials are those made up of layers glued and joined together such as in beams, or sheet material like plywood.
Laminate flooring has been hugely popular over the last few years (especially with landlords and parents)and is marketed as something anyone can fit as an easy DIY project. Click above to go to a page with more information and fitting tips.
A leading edge is most commonly found on doors. By planing the lock edge of the door at a slight angle (more off the side that closes first) you can achieve a tighter margin between the door and frame when in the closed position. A leading edge may also refer to cutting a slight angle on a piece of timber that is tight to install so you can start it off in a gap before beating it in a little.
Big business in the UK at the moment because many people are improving their homes instead of moving. Converting the attic into habitable space involves major structural alterations. Go to the loft conversion section for more information.
Carpentry Terms beginning with M
Stands for medium density fiberboard. Its a really versatile man made material and is available in a sheet form which is ideal for shelves, window boards and pipe boxings as well as pre-primed moldings such as skirting boards and architraves.
A miter box is a device used to guide a hand saw at 45 degrees. Used for cutting perfect mitres on moldings like architraves, skirtings and Coving/Cornice.
A timber molding is a strip of material such as softwood or mdf with a decorative profile cut on the face edges. Decorative moldings are most commonly used for fine finish and trim carpentry work (see also finish carpentry).
A normally square hole cut to allow a tenon to pass through and form a strong join between two pieces of timber.
Carpentry Terms beginning with N
The 'nominal size' refers to the roughly sawn size of timber before it is planed or machined.
Noggins or bridging as they are sometimes called are timbers place between studs or joists to strengthen the wall/floor and to carry the edges of sheet materials being used (flooring/plasterboard etc.). They are also installed in the walls at places where something will need to be securely fixed later on like radiators, kitchen units or a toilet cistern for example. You can see noggins in the diagram on the internal wall framing page.
Carpentry Terms beginning with O
Almost an 'S' shape molding. Found most commonly on architraves and skirting/baseboards.
The end of a power tool such as a table saw for example where the material exits.
Carpentry Terms beginning with P
Otherwise known as chipboard is made of lots of bits glued and compressed together. Available as a sheet material like flooring and also covered with Formica and used for worktops.
A type of screw head with a X shaped groove in the head. Special screwdriver bits are used to wind them in, not to be confused with Pozi shaped bits which are similar.
A pilot bit is a drill bit used to bore a hole slightly smaller than the screw to allow it to pass through the material easier and without splitting.
Means the angle of rise in degrees from the horizontal, used for staircase and roof construction.
The pitch line of a staircase is the point from which the handrail must be at least 900mm above (in the UK). This is obtained by laying a spirit level or straight edge onto the nosings of the treads.
Plumb is the term used to describe something that is perfectly vertical. A 'plumb bob' is an old fashioned heavy tool on a piece of string used to determine plumb.
Is a router that has telescopic style legs that allow the cutter to be pushed down into the work-piece to start cutting inside from the edge of a material.
Plywood is a man made sheet material made up of opposing layers and is used often for its strength and resistance to warping/shrinking.
A pocket hole is drilled at an angle to allow a butt joint to be screwed together. Can be used to fix two pieces together flush, at angles, end to end, curved and many more. Extremely useful type of fixing.
One of the best selling tools is a carpentry portfolio. With copies of qualifications and insurance certificates, photographs of previous work, testimonials and more. Go to the carpentry portfolio page for more information.
When one piece protrudes above another it is referred to as 'proud'.
Carpentry Terms beginning with Q
A quarter round or quadrant molding is a cover strip the shape of a quarter of a circle that comes in long lengths. It is used as a decorative bead and to cover gaps or areas where plasterboard meets timber and would crack without a cover strip. You can also use a router and round-over bit to put a quarter round molding onto timber.
Carpentry Terms beginning with R
Is a circular saw mounted on a horizontally sliding arm. It was the most popular saw for cutting timber to length before the miter saw.
A horizontal component fitted on doors for example where it acts as a brace to add strength and stability.
Rafters are roof members cut to make up the structure of the roof. Click above for more information, pictures and tips for setting out and cutting roof rafters.
Is a long, flat or curved steel tool like a file but rougher. Used for removing wood on curved surfaces.
Cutting parallel to the grain of timber is referred to as a rip cut or 'ripping'. The opposite of crosscut. Table saws are rip saws.
The term rise is used during staircase and roofing construction and refers to the overall vertical height the staircase or roof rafter must travel. Or, the total rise of a staircase when divided by the number of 'risers' will give the rise dimension of each step on the staircase. When taking measurements to build a staircase I also refer to the rise as the floor to floor measurement.
Boards that are sawn to size and edged but not planed smooth. Mainly used for framing/carcassing carpentry.
A router is a fast and extremely versatile cutting tool with a high speed motor. Typically used for rebating, dados, rabbets and many other shapes/profiles.
Carpentry Terms beginning with S
Is a wooden trestle often used in pairs to support the work-piece whilst working on it. Carpentry apprentices often make these at college during their apprenticeships.
Refers to the amount of time it takes for timber to dry. Timber is air dried, and every inch of thickness typically takes one year to dry. One season equals one year.
Unseen material used in furniture is often made up of 'secondary wood'. Sides of drawers, are one example.
When teeth on a cutting blade have been 'set' it means they are off-set alternatively on either side of the blade. They do this in order to create a cut that is wider than the blade is thick. This prevents kickback, when the timber pinches the blade during cutting.
Resin flakes that have been dissolved in alcohol and are then used as a decorative and protective coating for fine finishing timber.
Is a term used when two adjoining timbers are not flush with each other, one being below the other. The opposite of proud.
Or toe nailing, skew nailing is the method of fixing timber together at an angle when you cant fix through the back.
Also known as baseboards, skirting boards are the decorative moldings fitted during finish carpentry at the bottom of walls. Click above to go to a page with more information and fitting tips.
To snipe a work-piece is to gouge the trailing end of the material when running it out of a joiner, prevented by supporting the work-piece level as it exits the machine.
Timber sourced from typically evergreen conifer trees. Softwood doesn't refer to the hardness of the timber, some softwoods are harder than hardwoods. 80% of the timber used around the world is softwood.
Relatively low cost drill bits for cutting small to medium size holes. Available with either a point or threaded centre guide. When drilling thin materials with them put a scrap piece of timber behind the work-piece.
Works like a hand plane but is used to form and smooth curved surfaces as opposed to flat. The tools body is in the shape of two handles and the blade is fastened in between. Spoke shave blades are available shaped concave, convex or straight.
A carpentry hand tool used for setting out and marking or checking for square, true 90° angles. Other uses include setting out roof rafters and staircases. There are several different types of carpenter square available click the link above for more information.
The vertical member of a doors construction is called a stile.
Carpentry Terms beginning with T
A t-slot is a shape housed or machined out of the underside of two pieces that are to be joined together. Special dog bone shaped clamps are then used to hold the joint tightly together. Most common use is in worktops.
A circular rip saw blade that is mounted under a table. The height the blade protrudes and the angle are usually adjustable. Great for ripping sheet materials etc.
An essential on site measuring tool for carpenters. For tips on how to read one go to the tape measure page.
'Firring' strips are taper cut, whereby the width decreases from one end to the other. Easiest way to cut them is on a table saw using a special jig.
Tear-out of the timber fibres is caused when crosscutting timber. Avoided by scoring with a sharp Stanley knife first. Also avoided by using the saw to cut into the face first and out the back of the work-piece.
A template is either a preformed shape laid onto timber several times when making repeat cuts or a power tool guide. Common uses are as guides for plunge routers.
A mortice and tenon consist of a hole in one piece of timber (mortice) and a tenon that fits into the hole to form a strong joint. Commonly used in staircases, windows doors and other joinery.
A large planing machine used to reduce the thickness, clean up the surface of and square up timber.
Is a method for joining two pieces of timber. Tongue and groove flooring for example has a protruding tongue that is glued and slotted into the groove of the next piece. Also used for wainscoting.
Screws are available with torx heads, and they are driven with special star shaped screwdriver bits.
A type of square with a flat steel blade held at a perfect 90° and held in a wooden handle, often rosewood or mahogany (see also 'square').
If incorrectly stored or seasoned timber can have a tendency to twist along its length.
Carpentry Terms beginning with U
To 'undercut' timber is to cut more out of the back or side where it won't be seen. Like a leading edge, you would undercut a piece of timber to allow it to go back further or to tighten a miter or scribe for example. As long as it won't be seen from the face or will get covered by something else.
Carpentry Terms beginning with V
A liquid used to finish timber. It is a hard protective film often transparent but is also available with different coloured effects.
Often machined on tongue and groove flooring, the joining edges are chamfered/beveled so a V is formed when they are connected to each other.
A thin layer of wood is glued to another. Expensive timber can be replicated cheaply by using cheap timber with a thin expensive veneer.
Carpentry Terms beginning with W
The wall plates are the timbers fixed round the perimeter of a building or structure that the joists and roof rafters are fixed to.
When timber bends/twists along its grain when stored incorrectly or when drying out it is considered 'warped.
Carpentry Dictionary beginning with X
There are no carpentry terms here yet beginning with the letter 'X'
Carpentry Terms beginning with Y
A wooden rule 36" long, most commonly used for setting out and marking joinery work.
Carpentry Terms beginning with Z
Table saws have a gap round the blade to allow the angle of cut to be adjusted without cutting the table. A blank insert called a zero tolerance insert closes up this gap so that the workpiece is supported all the way up to the blade, allowing neater cuts.
Do you have a comment/question about any of the carpentry terms on this page or can think of any that are missing?