Full Chisel Blog

April 26, 2008

Board & Batten Building

Filed under: Of Interest,Uncategorized — Stephen Shepherd @ 6:35 am

Board & Batten Building 

This is a very simple board and batten, post and beam building.  It has a simple foundation of piled stones, but can be built down low with a dirt floor.  The drawings are for a building, built on a slight hill, hence the different piles of rocks.

String Layout

 

The first thing to do is to layout the size of the building.  This is usually dictated by the size of timbers and lumber that is available from local sawmills.  Of note in different communities the sizes of the buildings are always the size of the length of the local sawmill’s log carriage that determines the size of the buildings.  Or it is in multiples of the size of timbers and boards supplied by the mills.

 

Stakes are pounded into the ground at the corners, measuring diagonally to determine that the building is ‘square’, even though it is rectangular.  The string line is also determined to be level by using a whiskey stick (spirit level), transit or water tube.  The flat stones are then placed until the foundation is level in all the right places.

Stone Foundation

 

The sill plate is notched at the corners on the ends to lap on the long sides.  If there is going to be a dirt floor then the next step is not done.  It might be a good idea to run a strap of wood across the center to prevent spreading of the sill plates during construction.

First Bent

 

The floor joists are cut to length and with dovetail joints, sawn and chopped into the sill plates.  The ends of the joists can be cut with a hand saw into dovetails, and then used to lay out the receiving mortises (half blind dovetails, sort of) which are sawn and chopped.  These lock the sill plates into position and give support and a nail plate for the flooring which is laid loose until the building is complete.  This allows it to season and acclimate to the environment where the building is being built.  Some floors were laid loose and not nailed or pegged down until a year later.  Having the floor in place will help in building the remainder of the building.

 

Holes are drilled and mortises chopped down through the lap joints for the posts, which are tenoned on both ends.  One tenon for the mortise in the sill plate and the other for a mortise to be drilled and chopped in the rafter plate.

Joinery details

 

Bents are assembled on the ground and lifted into place.  A bent is a part of the structure that can be assembled on the ground and hoisted into place.  They can be from end to end or side to side, depending on the number of bents and size of the building.

 

Knee or wind braces need to be cut and the appropriate mortises chopped to receive them.  Their purpose is to prevent wracking of the structure under wind load.  When properly installed they make sure the building is plumb, level and square.  If the math, marking and methods are all accurate, the building will be remarkably square, plumb and level.

 

The rafters are simple laps, no ridge beam nor purlin and dovetailed tie collars with bird beaks and pegged with trunnels or treenails into the rafter plates.  The rafters are kept in place with skip sheathing of rough cut boards for the board and batten roof.

 

The studs and plates for the windows and door openings were sometimes joined into the framework or merely toe nailed in place where the fenestrations are required.

 

The roof is done first and the siding fit up underneath and allowed to run long on the bottom.  Boards are laid so that they will cup and form a gutter or trough and the Battens are laid cup down so they shed water, making for a tight roof.

Completed Building

 

The siding is put up the same way with attention to grain and cupping.  Flat trim can be added around doors and some were adorned with barge boards, corner boards and eve returns.  These buildings were the simple and common trade’s buildings in the nineteenth century after pole barns which are similar without the sill plates.

 

The finish woodwork of the doors, windows and other detail work completes this utilitarian structure.

 

Stephen

2 Comments

  1. Stephen,

    I notice in the 4th pic down, it shows what appears to be a scarf on the sill. I snap’d a pic at the Gamble House in Pasadena, CA, and there was a scarf on the sill with plugs in it. Here’s a pic (nice planter that I think makes a good project for folks that can be built in a day or two).

    http://softorchestra.com/images/gamble_planter.jpg

    Mostly I’m curious, this type of scarf on the sill must have been more popular before processing lumber in longer lengths was common. There are larger timbers of that era and before though, so I’m puzzled why there would be a scarf, other than material on hand??? The load is from above on the sill, so there should be little worry of the pieces separating, and even so your pic has a plug/tenon in it, so it would be secure, and the Gamble pic has a couple locking plugs in it from the side as well (I like that touch;-).

    The dovetailed joists (???? not sure if those are considered joists) into the sills. That’s a nice touch, and seems like a nice joint for that particular application. Nowadays I ‘spose they just butt ’em up, and drive nails in with an air nailer…until things stop moving…

    Comment by Alan — April 26, 2008 @ 12:44 pm

  2. Alan,

    The scarf was necessary because of the limit of length of sawn timbers, not a problem if you hew the log square. Scarfing is common, this is a simple, some have interlocking dovetails with folding wedges to lock them together.

    The dovetail joists are good to prevent spreading of sill plates, helps in a seismic 3 zone. I have seen ceiling joists attached using the same dovetails. Not that much harder to cut than open face notches.

    Balloon framing is common during the mid nineteenth century so studs, plates and nails will replace this type of construction in all but barns and large buildings.

    Stephen

    Comment by Stephen Shepherd — April 26, 2008 @ 1:25 pm

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