Traditional joinery is a term we’ve all heard as a hallmark of historical millwork.  But what is it and why is it so important in preservation of historic buildings?

What is Traditional Joinery?

Joinery in general is the woodworking technique that joins together two pieces of wood.  What a joint looks like, how strong it is, how long it will last, and other characteristics are all determined by the joining materials and how they are used in the joints.   Traditional joinery techniques use only wood elements, while modern joinery techniques use fasteners, bindings, and/or adhesives.  Sometimes the two techniques are combined to marry wooden elements and joints with modern adhesives.

Traditional joinery uses the following joints:

Butt joint: The end of a piece of wood is butted against another piece of wood. This is the simplest, and weakest, joint in traditional joinery.

 

 

Miter joint: Similar to a butt joint, but both pieces have been beveled (usually at a 45 degree angle) before being joined together.

 

 

 

Lap joints: One piece of wood overlaps another.

 

 

 

Box joint (or finger joint): Several lap joints at the ends of two boards; used for the corners of boxes.

 

 

 

Dovetail joint: A form of box joint where the fingers are locked together by diagonal cuts.

 

 

 

Dado joint: A slot is cut across the grain in one piece for another piece to set into; shelves on a bookshelf having slots cut into the sides of the shelf, for example.

 

Groove joint: The slot is cut with the grain.

 

 

Tongue and groove: Each piece has a groove cut all along one edge, and a thin, deep ridge (the tongue) on the opposite edge. If the tongue is unattached, it is considered a spline joint.

 

Mortise and tenon: A stub (the tenon) will fit tightly into a hole cut for it (the mortise). This is a hallmark of Mission Style furniture, and also the traditional method of jointing frame and panel members in doors, windows, and cabinets.

 

Birdsmouth joint: A V-shaped cut in the rafter connecting roof rafters to the wall-plate.

 

 

Comb Joint: A joint used as a way of conserving timber, as a means of joining random lengths of timber to be machined to a finished piece.

 

 

 

Source for pictures and joint descriptions: Wikipedia’s Entry on Traditional Woodworking Joints 

 

Why it’s Important in Preservation

There are many advantages to using traditional joinery in the preservation or restoration of a historic building.  Using traditional joinery in repairs, restorations, and other preservation ensures the structural integrity of a historic building by matching existing joinery with a joinery technique that’s sure to be compatible with it.  Since traditional joinery is stronger, more durable, and expands and contracts in different ways than modern joinery – using modern joinery alongside traditional joinery can compromise the structure of a historic building.

Traditional joinery is a time-tested method that is much stronger than modern joinery and lasts for generations, even thousands of years.   The mortise and tenon joint is the most ancient traditional joint and has been found in the wooden planks of a vessel 43.6 meters long that dates to 2,500 BCE.  Traditional Chinese architecture as old as Chinese civilization itself used this method for a perfect fit without using fasteners and glues.  The 30 stones of Stonehenge were also fashioned with mortise and tenon joints before they were erected between 2600 and 2400 BCE.

Proving itself to be able to stand the test of thousands of years, traditional joinery is clearly a higher quality and more stable joinery method than modern techniques.  That test of thousands of years also demonstrates traditional joinery’s ability to withstand the rigorous use we often demand of our structures joints because it is a higher quality, more stable joinery method than modern techniques.

One of the reasons traditional joinery like mortise and tenon joints withstands the test of time so well is that it allows a joint to naturally expand and contract with moisture and temperature changes in the environment without devastating separation that weakens the joint and causes (often irreparable) damage to the wood pieces it’s joining together.

But most importantly, traditional joinery ensures authenticity in the preservation of our built history by more completely matching the existing materials and construction methods used by traditional trades.  Since the traditional trade methods that originally constructed a building (along with regional variances in those methods) are a large contributor to a building’s historic fabric, this is the best way to make sure that historic fabric is not lost to our preservation efforts.  Traditional joinery also better allows for selective repair or reconstruction of individual components than modern joinery methods – a major advantage that helps preservationists retain more of the woodwork original to a historic building.

 

 

 

In the summer of 2011, the tower at Independence Hall was bared to the bones for the first time since it was added in 1828.  In a restoration project for the National Park Service (NPS), contractors bared the face level of the tower down to the structural framing.  The NPS has a detailed write-up of the project, along with pictures, videos, and step-by-step pictorial guides of the process.

CLICK HERE TO CHECK IT ALL OUT AND TAKE A LITERAL LOOK INTO HISTORY

“You can’t have your cake and eat it, too” might apply in the kitchen, but when you’re building houses, you sometimes can have both.  If you like timber-frame houses but can’t afford one, consider a hybrid.  Although a complete timber frame usually costs 10% to 20% more than a comparable stick frame, a small timber-frame structure integrated into a stick-frame house adds only a fraction of that cost.  Hybrids also are less complicated to build than full timber frames, yet they retain the dramatic look of timber-frame structures in visible areas.  These timber-frame parts can range in scale and complexity from a simple covered entry to an entire two-story addition.  In a typical situation, a timber-frame company such as mine is used as a subcontractor and provides the materials and installation; we also have supplied materials and/or assembled components for builders.  The following are some examples of projects we’ve built.
Entries and porches: A little timber goes a long way
A home’s entrance serves as a transition between outside and inside; it should be protecting and inviting.  A timber-frame entrance (see photo) satisfies these requirements and is relatively easy to build.  Typically composed of two trusses and connecting girts, the structure is lag-bolted to wall studs through the sheathing; the posts are anchored to a masonry pad or footings with noncorrosive standoffs and 1-in. dia. Galvanized-steel pins (see drawing).
Building a flat-ceilings timber-frame porch is also fairly easy (see photo).  The porch is built with a series of posts, girts and braces that support a simple stick-frame roof, which in turn ties the timber frame to the house.
Any number of styles is possible.  Entrances can be as simple as a single bent with a ridge, purlins and side girts that die into the exterior wall.  A large entrance can be even more elaborate.  Railings can be integrated into the posts, or the posts can be doubled up.  Whether on a porch or a deck, posts that look too feeble to support even themselves are the one thing that most diminishes the presence and personality of a house.  We always recommend that substantial posts and girts be used – say, 8x8s and 6x10s, respectively.  If these dimensions look too heavy, the beams’ edges can be chamfered or beaded for a lighter look.
Sprucing up the ceiling with a floor system
A timber-frame floor/ceiling system usually consists of a massive central, or summer, beam that supports the smaller joists (see photo).  The drywall then can be placed on top of the timbers, and a sound-deadening floor (usually layers of plywood) or a conventional 2x-joist floor can be built above, especially if ductwork is an issue.  For a wood ceiling, tongue-and-groove boards are usually the materials of choice, followed by a built-up floor or 2x joists.  Some builders may opt for a single layer of tongue-and-groove boards, but sound transmitted between floors can be irritating.
Opening a space with trusses
The most popular hybrid form is the timber-frame truss system (see photo).  Most often, trusses are placed in a large open space, such as a great room.  Heavy trusses generally can be spaced 16ft. apart if they’re connected with purlins (see drawings) spaced 4ft. o.c.  If the purlins don’t fit in the design, more trusses with closer spacing do the trick.  In such a scenario, tongue-and-groove ceiling boards run perpendicular to the trusses rather than parallel as they do with purlin connections.  It’s usually more economical to go with the purlins because fewer trusses are used.
Other considerations include roof pitch and span-loading requirements.  In terms of structural effectiveness as well as aesthetics, scissors, hammer-beam, and tied-rafter systems work better with steep pitches (12-in-12 or greater) and shorter spans (24ft. or less).  Whatever the choice, review  any design with a licensed structural engineer.
Incidentally, for whatever type of project that we’re working on, we have drawings sealed by a registered engineer because loading requirements can dictate not only the shape but also timber size and spacing.  The relatively low cost of an engineer’s time is money well spent.
Truss design can make a space feel contemporary and light, medieval and heavy, or just about anything in between, depending on configuration (see drawings), timber species, surface, and finish.  Ceiling materials also has an impact.  White drywall or pickled tongue-and-groove boards can help a tight area to feel larger; dark painted drywall or clear-finished tongue and groove can make a high ceiling feel lower or make a large room feel more inviting.
This article originally appeared in Fine Homebuilding Magazine and was reprinted with permission from Anthony Zaya of Lancaster County Timber Framers, Inc.


Taken from the Historic Wood Windows tip sheet from the National Trust for Historic Preservation – maintenance is important for all areas of a building to help insure that it will continue to perform without costly repairs. Preservation is maintenance and it is a lot less expensive than replacement.

Four Wood Window Maintenance Tips:
1. Keep exterior surfaces painted (keeping the water out of the wood);
2. Repair glaze – reglaze entire window as needed;
3. Don’t paint the window shut – so that it can operate as intended; and
4. Don’t paint the sash cord.

For more information read “The Repair of Historic Wooden Windows” Preservation Brief Series #9 – www.cr.nps.gov/hps/tps/briefs/brief09.htm

The November/December 2009 issue of Preservation Magazine featured an article, Getting Ready for Winter: 15 Steps to Efficiency. These tips are taken from this article.
  • Insulate the attic (this is where the majority of your heat loss will occur – though the replacement window and door companies would have you believe it is on the walls of the house – heat rises.)
  • Zoned heating system (heat only the areas of the house you “live” in).
  • Bleed radiators and clean forced-air vents.
  • Have your furnace serviced.
  • Change your furnace filters once a month.
  • Install a programmable thermostat (turn the heat down at night when you are in bed and during the day when you are away).
  • Insulate duct work and hot water pipes in cool spaces. Install foam inserts behind electrical receptacles and light switches (they sale the inserts (with precut holes) for behind the covers at any hardware store).
  • Close fireplace dampers (when the fireplace is not in use – we have had a call from someone not sure why their house was filling with smoke).
  • Set ceiling fans to low and switch direction so the hot air is being forced downward from the ceiling.
  • Make sure bathroom fans have functioning dampers.
  • Keep your original windows maintained (caulk, fix glazing, replace broken panes, repair wooden parts, and install weather stripping).
  • Install storm windows.
  • Use lined curtains, working shutters, and insulated window shades.
  • Caulk holes at exterior penetrations (mail chutes, etc.) only use exterior-grade caulking for this job.
Wrecker or Builder
I watched them tearing a building down
A gang of men in a busy town.
With a ho-heave-ho and a lusty yell,
They swung a beam and a sidewall fell.
I asked the foreman, ” are these men skilled,
As the men you’d hire if you had to build?”
He gave a laugh and said, “No, indeed;
Just common labor is all I need.
I can easily wreck in a day or two
What builder have taken a year to do.”
And I thought to myself as I went my way,
Which of these two roles have I tried to play?
Am I a builder who works with care
Measuring life by the rule and square?
Am I shaping my deeds by a well-made plan,
Patiently doing the best I can?
Or am I a wrecker who walks the town
Content with the labor of tearing down?

Clarence E. Allerton, Local Union 439, Orange, N.J.

Rainy Days…



What to do when a wet Nor’Eastener settles over Staten Island on a work day? Take the ferry to the Big Apple! Lois and Chuck went on an adventure in Manhattan last Friday. We arrived at the Staten Island Ferry Terminal at noon and mingled with the local fokes waiting to board the ferry to the City. Hearing serveral different languages spoken by excited young adults making their way around the deck. As we all braved the wind and the rain to watch the tug boats, tankers, and ships glide along the Hudson River. Lady Liberty appeared out of the fog to greet us, a beacon of hope and welcome for the past 100 plus years. The ride was actually fast, about 15 minutes. Landing in the Battery Section of lower Manhattan.. Of course Chuck and I walked around, looking up, pointing out the architectual details on the buildings to each other, like a couple of tourist. We even walked to Wall Street, there were a lot of people in the bars….

Catching the ferry to return to Staten Island at the end of the day was another eye opening event. Dare I say thousands of people gathered and boarded the ferry. This system of transporttion works and its free. Historic Restorations will have a field trip to the city again, we will make sure that the kids experince this too.

Green building is all the rage in the building industry. I can not open a remodeling or design/build magazine without a reference to a green building project. Preservation and restoration work is green in it’s approach. By using resources (building materials) that have already be harvested on land that has already be cleared is a greener approach than building a brand new building using new green materials. When you are building a new building you have to create the resources, ship them to the building supply store, and then ship them to the job site on the newly cleared land (from farmland, forest, or a tear down).

Storm Cunningham in The Restoration Economy (covering all aspects of the restoration economy natural and built environments) states that 25% of all landfill waste is from construction activities. By reusing the salvaged materials from buildings that are being torn down in our restoration projects we are keeping those materials out of the landfills.

It is easy with these new green materials to refer to new building as green. The new building materials are green for a new building approach but that approach is not necessary the best method when working on an older home (one built before 1945). There are ways to take a green building approach when dealing with your older building that does not include retrofitting inappropriate modern materials.

Last Saturday, June 7, Chuck, Lois, and Danielle drove to Bellefonte, Pennsylvania (right above State College) to conduct a seminar for the Borough of Bellefonte as part of their wood window seminar day in the park. There were various other exhibitors (replacement windows, storm windows, and stained glass window experts with booths) as part of the window fair.

It was a hot day with high humidity on top of the heat – I would describe it as oppressive. We made do with the weather (which impacted the turn out) and moved our presentation into the park gazebo where there was shade and benches for the attendees.

Despite the small crowd we had a good time discussing the importance of wood windows to a historic building, the replacement cycle (caused by inferior new growth wood and modern construction practices – the replacement window salesman was not happy with this aspect of the discussion), and storm window options (interior and exterior). We also covered energy efficiency of wood windows, with support from the University of Vermont Wood Window Report (showing the energy savings is less than a dollar a year when wood windows are replaced with modern replacement windows), how to make wood windows more energy efficient, and a demonstration of the steps to repair wood windows.

We enjoyed sharing our knowledge with the few concerned homeowners and the Borough of Bellefonte’s available HARB members. We look forward to visiting this Victorian city again in the near future.