Our main priority is to ensure that the clients needs are being met.

To this end we make use of CAD which enables us to generate drawings at full size.

Printouts can be made to any scale – one tenth scale may be suitable for a concept model.

The illustration above was generated from a normal CAD line drawing enhanced to give an impression of how the  final building should look.

Concept Model generated from CAD Drawings

Here we can see in the round how a final building might look.

This enables us to illustrate any project and allows the client to modify the design by say adding doors or windows.

Proposed changes can be fed back into the CAD system to check if they are practical within the given budget.

In joinery there are two main systems for constructing timber framed buildings – Scribe Rule and Mill Rule.

1. Scribe Rule Joinery

Each joint in the whole building is unique.

Exact dimensions are Scribed (marked with a sharp point) on each timber.

Cuts are then made by chisels and manual coping saws to remove portions of wood until a perfect match is achieved.

In order to do this the whole frame must be laid out in a workshop or yard.

Since the timbers are an exact match for their position they need careful tagging or marking systems to track their future assembly.

Scribes, Plumb bobs and specialised transfer tools are often used to check the layout.

Joe Thomson who was carpenter-in-residence at the Weald and Downland Museum taught this complex labour intensive English system of ‘Scribe Rule’.

The illustration on the right is by the Timber Framers Guild

2. Mill Rule Joinery

Plans are either drawn manually or created by Computer Aided Design (CAD).

Various large industrial machines are used to mill and plane the timber components to true and consistent dimensions.

The final layout can be done from any face and timbers may be interchangeable.

Steve Chapell who runs the Fox Maple School of Traditional Building in Maine, USA taught the much simpler American system of ‘Mill Rule’.

The precision Mill Rule system is the most commercially viable system producing fine quality consistent results and as such has been adopted at Thomson Timber.

The Woodmizer Sawmill illustrated above is only one of the wide range of precision woodworking machines we use.

Glossary of Woodworking and Joinery Terms

TIMBER PIECES
Beam	a main horizontal member in a building’s frame
Braces	smaller timbers placed diagonally between posts and girts or plates to make a structure more rigid
Collar Tie	a timber placed horizontally and between rafters that control spreading or sagging of the rafters, usually placed parallel to the girts which connect rafter pairs at a given height
Common Rafters	closely and regularly spaced inclined timbers that support the roof covering, independent of the bent system
Found Curve	naturally occurring crooked timbers usually with two sides sawn and two sides with the bark removed, used as knee braces, posts and beams
Hammer Beam	a horizontal timber projecting from the top of the wall or rafter that supports a roof truss. The design creates a large roof span with relatively short timbers
Intermediate Wallplate	major horizontal timber that connects posts
Joist	smaller horizontal timbers parallel to each other to complete the floor frame
King Post	a central, vertical post extending from the bent plate or girt to the junction of the rafters at roof peak
Knee Brace	a short diagonal timber placed between the horizontal and vertical members of the frame to make them rigid
Plate	the major horizontal timber which runs from one end of the frame to the other and supports the base of the rafters
Post	upright or vertical timbers erected within the frame that provide structural support of the members above
Post with Teasle Tenon	a post having an increased size at its top, providing extra strength for intersecting joinery
Principal Rafters	a pair of inclined timbers that are framed into a bent and used with either purlins or secondary rafters or alone
Purlin	a horizontal member of the roof frame which runs between rafters
Queen Posts	a pair of vertical posts of a roof truss standing on the bent or girt and supporting the rafters or collar tie
Rafter	sloping main timber of the roof frame
Ridge Pole	horizontal timber which connects rafter pairs at the peak
Ridge Purlin	the beams connecting rafter to rafter at the apex
Secondary Rafters	smaller sized timber rafters placed between principal rafters
Sill Timber	major horizontal timbers which lie on the foundation and form the lowest part of the frame
Strut	a short timber placed in a structure either diagonally or vertically, designed to act in compression along the direction of its lengths
Summer Beam	a major horizontal timber which spans the girts or plates
JOINERY
Dovetail	a tenon that is shaped like a dove’s spread tail to fit into a corresponding mortice
Half-Dovetail	this joint is one-half of a dovetail; used for joining collar ties to rafters, and braces to posts, and for other similar situations
Half-Lap	a joint in which two timbers are let in to each other
Joint	part, or the arrangement of the part, where two or more timbers are joined together
Haunch	the part of the whole timber beyond the shoulder which is let into another timber
Housing	the shallow mortice or cavity for receiving the major part of a timber end, usually coupled with a smaller deep mortice to receive a tenon tying the joint together
Joinery	the craft of connecting and securing the separate members of the timber frame to one another by means of specific cuts on the ends and/or sides of the timbers
Mortice & Tenon	any joint consisting of a projection (tenon) on the end of one timber and a corresponding slot (mortice) on the other
Peg	a hardwood dowel usually ranging from 5/8 of an inch to 2 inches in diameter
Scarf Joint	a joint used to splice two timbers end to end
Shoulder	the area of the void created when the waste around a tenon has been cut away
Tail	the end portion of a birds-mouth joint which extends beyond the plate when there is a roof overhang
Tenon	the projecting end of a timber that is inserted into a mortice
Trunnel	also known as a tree-nail, a turned and tapered hardwood dowel used for securing timber joints. See “Peg”
Tusk Joint	also called a tusk or through tenon, a mortice and tenon joint in which the tenon goes all the way through the corresponding mortice
TOOLS
Beetle	a heavy wooden maul or mallet used in cases in which material would be damaged by a sledge hammer
Come Along	a hand operated ratcheting wrench. Uses include tightening joinery during assembly, as a safety tie and for pulling frame components together during construction
Draw Knife	a tool having a blade with a handle at each end; by drawing it toward you, you can shave surfaces
Framing Chisel	large chisel with long, heavy blades strong enough to be hit with a heavy mallet
Mallet	a tool like a hammer with a wooden, rawhide or rubber head
Pike	a long pole with a pointed steel head used in raising bents; also called a barn pole
Slick	a wide bladed and long handled chisel pushed by hand to create flat surfaces
DETAILING
Chamfer	a decorative edging or relief made at the timber’s corner
Pendant	an ornamental termination to the low end of a hammer post, king post, queen post, etc.
Stop	decorative end of a chamfer
OTHER TERMS
Bay	space between two timber bents
Bent	a structural section of the frame which is composed of a line of vertical posts and the horizontal timbers that connect them
Bent Design	the functional and artistic pattern of timbers creating the bent
Blue Board	weather resistant, plaster-based drywall
Check	a separation of wood fibers caused by the natural process of wood drying
Green Wood	freshly cut wood that is not dried or seasoned
Hand-Hewn	a timber squared off and shaped by hand
Hardwood	wood of certain deciduous trees (e.g., oak, walnut, ash, etc.)
Rough Sawn	lumber and timber that has not been planed
Scribing	shaping one member to the surface which it touches, for example, to fit a board snugly to a surface which is not straight
Span	the width of a building or overall length of a truss
Timber Frame	a load-carrying structure of timbers ranging in size from 4×4 and up
Wall Decking	lumber covering the walls usually 1″ tongue-and-groove