Corn Crib as Geometry

A corn crib.
Little. 17 ft by 21 ft , about 18 ft to the peak.
New roof, south facade, and paint: c. 2015. Painting on going.
New concrete blocks for piers; old  concrete piers formed in wicker baskets.
Moved, maybe by oxen.
Door relocated for easier access on foot. The main door was on this elevation, about 3 ft above grade, ideal for access from a wagon.

This south wall was rotting away.
The corn crib deserved better.
During the repairs we found that it is timber framed, scribed, the main framing beams hewn, others cut with a sash saw.
It has log rafters. and may predate the c. 1810 house.





The scribe marks are similar to others found in the neighborhood - a common framer? Or a common teacher of corn crib builders?

Click on the photographs to enlarge them and read 'II', 'IIII', and 'III' on the posts and the beams. 'III' shows how water in that joint wore it away. 

I measured it - the width, length and height; the size of the posts and beams, and their locations; the roof pitch, the slant of the walls. I drew it up and checked my notes for clarity. 



The plan and elevation are below. The sides were for corn, the center aisle for work, the back (lower) section for grain, tools, equipment.

The walls slope out to shed the rain and snow, and to keep the corn from locking in place. The beam running below the beam at the eaves supports the floor of the small loft above the back storage section. There is a ladder built into the wall for access.

This is a normal corn crib for this section of the Hudson River water shed where New York, Massachusetts, and Vermont meet.
It does not seem to be the usual way corn cribs are built in other parts of the country.  I plan to look more carefully.

How I 'found' the geometry:
Note: the geometry is right there. It does not need to be found. I need to recognize it!
Looking at the  floor plan I could see the posts in the upper section forming a square. I added the diagonal and then using the diagonal as a radius I swung an arc. It landed on the lower left corner of the crib.
This is a simple easy plan. The elevation should be as simple.
I tried a square based of the width of the floor (about 17 ft. wide). It didn't quite fit.
I tried a square based on the width of the walls as they meet the roof  (about 18 ft. wide). Again, not good enough.

The utilitarian corn crib's frame needed to be as straightforward as its plan. The geometry tell the carpenter where to put his frame - exactly. Not within  4-5 inches.  He will have timbers laid out on a framing floor. He will want lines (chalk lines or taunt twine) that tell him position, lengths, mortises.  He needs no frills here.

This is when I have a cup of coffee, clean up the office, walk to the mailbox. And think, "The carpenter began with the height of the corn crib equaling its width. He put the loft floor at half the height of the crib."  I come back to try something else, experiment, play. "What if I drew the 'square' using the angled walls? Why not?"

It works. The Lines cross above and beside the framing members. The trapezoid ends below the ridge telling the framer where to cut his joints on the rafters so they will lap each other. The side braces (dashed line) are easily located.
The Lines on the framing floor will be beside the posts and beams, just as they are outside the edge of the plan.
The Lines needed to erect the crib are as minimal as those needed to layout the floor.

The geometry of a 1870's barn

 This Vermont barn was built in the 1870's . It has been used for storage for the last 20 years.

I prepared a report on its history and structure for its owners so they could consider repair and reconstruction with some real knowledge - not just good memories and/or worry about costs.

The barn was well built by a farmer who knew his land and a framer skilled at his trade.
The frame is regular, much of it still sturdy. Its mortises,  tenons, and pegs are still secure.














Its bents use dropped girts and posts to purlins which support  common rafters, a framing system regularly used in the Hudson Valley watershed, not often seen in this area of Vermont.









While I was not asked about the barn's geometry, as I laid out the plan and the frame I could see the geometry clearly - not complex, quite simple, repetitive, and straightforward.


Here is the 3rd bent and the lower level floor plan.
The bent is one of the 4 timber frames across the barn that are then fastened together with plates and girts. Walls and flooring have been left out.
The plan is mainly the post locations. I have not included the exterior wall girts.  The braces which are visible in the photograph to the right are barely noted.

The floor plan could easily have been laid out using circle geometry.

I have added Laurie Smith's diagram for drawing a square beginning with a circle. It is a very clear description.

For his websites see: http://www.thegeometricaldesignworks.com/

and  http://historicbuildinggeometry.uk/

Here is my drawing of the floor plan with its posts laid out using circles. The first  (top) 2 bays are of equal depth and width.  The dashed green line shows the layout determined by the circles.

The lower bay (between bent 3 and 4) is not as deep. Perhaps the land dropped off too steeply, or the lumber available was not as long. The dotted red line in the lower right rectangle shows how the crossing of the arcs of the square determined the depth of the bay. 

The base of bent 3 is vague on purpose. I don't really know the depth of many of the lower level posts. The land slopes west to east. The floor on the east end has been built up over the years with layers of discarded boards.  The right end has been reconfigured for cows; the left end has a false ceiling.
The main  barn level of the bents is divided into thirds. The  posts are the height of a third of the bay's width - the space they outline is a square. I've drawn it in red. The dropped girts are set at the point where the arcs of the square cross. Also drawn in red.
This is similar to how the lower level east bay's depth was determined.
The posts that support the purlins ( the roof beams ) are centered on the squares below. The height of the ridge is also determined by where the arcs of the loft square cross.






Lastly the location of the lower girt which becomes the plate for the wing is determined by the Rule of Thirds.



Such basic practical geometry tools! They are  those described by Serlio, Palladio, and Asher Benjamin - circles, arcs, lines - applied in very simple ways with impressive results.


Well thought out, straightforward without fancy flourish, the space and the frame speak to me. But I am simply the one who documented this, sharing the power, the grace, that I found.

The barn, after 150 years, is no longer essential. It is very possible that it may not survive until a new purpose discovers it.

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Jackson, NY, House - a Dutch vernacular frame, 4 of 6 posts

 

written January, 2016

The house has been stripped to its frame. The sheathing removed, each board numbered as it came down. The stair and moldings (inside and out) carefully moved into storage.

Now the frame is visible -
no ridge beam,
12 bents: each is a post on either end mortised to a 2nd floor joist.
The plate across the top holds them all together; The 14 rafters sit on the plate and are not spaced to match the bents.

The joists on each end are mortised into posts.
Plates, mortised into the sides of the  posts, space the bents and carry the intermediate 2nd floor joists.

Here is a post with its joist and the pegs that hold the tenons of the plates seen from the outside.

Here seen from the inside, are: 2 posts, an intermediate stud; 2nd floor joists, plates and intermediate joists.
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.
We think it was assembled bent by bent, the intermediate plates added one at a time as each bent was set into the sill.







I have measured the first floor - twice The first time it was just too cold. I hurried. I wasn't careful.

The framer used Hudson Valley Dutch framing. The house was clothed in the latest Federal style with possible Shaker influences. Inside it retains the traditional system.  

I need to add more, especially about the Dutch way of framing.
An orthographic perspective would make the frame easier to read.
The frame details deserve a post of their own.
So does the careful cleaning and repair of the frame by Green Mountain Timber Frames.
I want to redraw the front elevation to reflect the frame we saw and measured compared to the plaster and clapboard surfaces I saw and measured in the beginning.

However, it is July, months later.  Time to share!


The link to  the men who took down and repaired this house, Green Mountain Timber Frames:  https://www.greenmountaintimberframes.com .

Jackson, NY, House, Introduction, 2 of 6 posts

A report from this summer - when I first explored the house - to accompany the geometry of the previous post.


Today the house is being dismantled, piece by piece - see the end of this post -

I have watched this small house for more than 10 years, hoping its Dutch framing and Federal style would endear it to a new owner. Its shape and proportions, its entrance, frieze and rake are beautiful. I am delighted it has been purchased.

 I explored it twice inside and out, basement to attic framing, and herein share what I saw.

The house was added to an earlier home, now gone, which then became the service wing.  The stone foundation for the first house exists as does a partial roof and ‘ghost marks’ and well as doors connecting the new and old wings.

 The original home, which faced south, included the kitchen and bath.

The frame on the east side is exposed. Brick nogging used as fire stopping and insulation is visible as is a solid post and beam system, approximately 3 ft. on center, with intermediate studs.  

The southwest corner of the 2^nd floor  appears to be an H-bent – a traditional Dutch method of framing.  The roof frame is pegged common rafters.  Dismantling will show more.

The wall and ceiling plaster was applied to split lath:  ½” wood planks forced apart with a hatchet so that the spaces in between would hold the plaster.

                                                                          

The foundation is local stone. There is no basement fireplace, just support for the one above. The photograph shows the mortise and peg on one end of the beam supporting the stone hearth in the living room.

The north side of the basement, beyond the stair, is a crawl space. Some floor joists have been somewhat compromised by the intrusion of plumbing and heating systems. These will be repaired.

In 1790, the house faced the main road between Lansingburg, NY, and Rutland, VT, 2 growing commercial centers. Many people would have passed by, traveling about 5 -7 mph on foot or  in a wagon, 12 mph if on a ‘Trotter’, a fast horse.


No one traveled so quickly that they would  not have noticed and admired the front door with its entablature and columns, its frieze and rake at the eaves, and even the ¾ rounding of the corner boards.

The bead on the corner boards is a typical detail in this area when the house was built - here shown on another house. Those on this house are too worn to be salvaged. The original door has been lost.

The windows were once the height of the front door. The short sections of siding above the modern windows indicate the original size. The exterior window casings would have been flat boards with banding. The header protruded to shed water and protect the window. The sills appear original. The sash was double hung, maybe 8/12 or 12/12 panes.





The interior door’s lights and the transom window’s proportions will help determine the right pattern.

    

                                                                      

The fireplace has a stylish Federal mantle like those seen the patterns books of Asher Benjamin and Owen Biddle. The marble surround is typical for the area. The bricked-in firebox is a Rumford – modern for the time - designed to radiate the heat of the fire into the room.  

By 1830, cast iron stoves were widely used. The chases for stove pipes are visible in the bedrooms.

                                                                                                                                            

The cupboards on each side of the fireplace were for dishes, herbs, spices and medicines as well as books and writing supplies. Notice how the modern, short window is an uncomplimentary shape.

The door and window casings are as elegant as the front door. The window casings are original, but were cut down when the windows were resized.  I have taken profiles for reference.

Dismantling the house may uncover traces of a wall separated the living room from a front hall with its stair case anchored by a graceful newel, well scaled to the small space.

The oval rail fits well in the hand.

 Square balusters march up the stairs and around the hall above. To turn 40 balusters by hand for the railing and have them all match would have been a tour de force in 1790. However a cabinet maker could readily turn one newel post.  It, like the front entrance, is Neo- Classical, the emerging style c. 1800.

                                                                       


For over 200 years people have lived here, loving the house, adapting it to their needs. Their footsteps have worn away the door sills.

The house itself is still strong.  I am happy to help send it to a new owner. Here it is coming down, board by board, brick by brick.

previous post:  http://www.jgrarchitect.com/2015/12/a-jackson-ny-carpenter-used.html

The link to  the men who took down and repaired this house, Green Mountain Timber Frames:  https://www.greenmountaintimberframes.com .

Jackson, NY: a carpenter used squares as did Biddle, 1 of 6 posts

 

 July 2022: time to review this: the 3/4/5 rectangle, thus the carpenter square, may be the basic geometry, not the square. And the sequence of the frame, how it was laid out, deserves attention.



Pass by this house. Enjoy how it is sited between its fields on the left that slope down across the flood plain to the river, and the road and the hill to the right.


It seems abandoned  - although someone carefully closed the shutters on a second floor window.

The broken dormer says there once was a wing - or the earlier house.


In the years that I've watched it, I've  thought:
C. 1800,
Dutch framed, H bents.
The new wing an update to the original farm house,
Set into the hill below the wind.

The old house, a story and a half cape set lower on the land, would have had easy access to the farmyard and the fields. It faced south to the sun, watching the traveler approach. The new wing is set higher, more worldly and 'speaks' to the road instead.


But how sad it is... broken chimney, no paint, dumpy windows,


A dilapidated front door


surrounded by fluted columns, complex and flaring capitals, a segmented architrave that curves,
the original transom,

Please click to enlarge the photograph see the lovely curved details of the architrave.

And rotted wood for plinth blocks/bases.

Worth restoring?


It will be.
The frame is well built. Here is the mortise and its peg for the beam which supports one side of the fireplace hearth,

Dismantled, repaired, it will be reassembled on a new site
with its original casings, doors, newel, and mantle.

The shape is simple: 18 ft wide by 36 ft.long. 2 rooms each floor.
2 boxes.
I thought of Owen Biddle's plan for a 'small house'.* That plan used 2 squares divided into 4 parts. Would squares divided in half work here?
Or would I find Asher Benjamin's use of squares divided in thirds?

Owen Biddle's simple division of the square works here.






The plan is 2 squares. The interior wall at the stair is located at the 3/4 mark of the left square.

The windows are placed on the centers of division of the original square . Those on either side of the fireplace are easy to read:half the big square divided into 2 little squares.

The windows beside the front door are centered on rectangles that are 1/4 of the large squares.

The cross section of the house follows the same pattern.

The first floor volume is 2 squares long and half a square high.

The height of the exterior front and rear walls is 3/4 of the square.


The second floor height is 3/8 of the height of the square.

The division of the basic 18' x 18' square into smaller parts is done by diagonals. It is visual. No one needed to write down fractions.



I think the ridge is another 1/4 the height of the square above the ceiling joists.  However since the second floor ceiling is still mostly intact, I could not measure the height to the ridge nor the slope of the roof with enough accuracy to be sure. The interior slope of the ceiling was consistent






The sadly sized windows - replacements when repair of original windows could have saved them - have mismatched clapboard above the lintel which outline the size of the original sash.








Here is my drawing of  the front of the house with its original sash. I do like this house!

The geometry follows that of the floor plan - the square divided into its integral squares and rectangles. The intersections of the diagonals give the dimensions.
The right hand square of the house is drawn. The center line  (A - A dividing the square into 2 equal rectangles) marks the top of the entrance - probably the framed opening, not the casing.
The right window (B) is centered on the small right square which is 1/4 of the large square  or at the 1/4 mark of the right side of the house.

I think about this in 'geometry', but it is hard to show when I can't use my hands. Thus I am adding the  fractions.






 The left window (C) is centered on the half of the small left square, just as in the floor plan or at the 5/8 point.

The size of the window and where it fits in the wall is also determined by the intersections of the diagonals of the square and its parts. Here the right hand square is divided into 2 equal rectangles. I have drawn the lines in green and added emphasis at the intersections.

I measured the height of the front wall from the inside. I did not measure the eave overhang or the frieze. Here I have just laid out the diagonals of the upper half of the square to see what i might find. It looks like it might be right. I will have real dimensions when the house is dismantled. I might be right, or learn something new.






Here is the interior second floor corner where the frame is exposed. The posts which are visible are not regular in size. There is some interesting bracing.  Does the frame also correspond to the rhythm of the square?
I hope to find out.







* See  http://www.jgrarchitect.com/2015/11/owen-biddles-plan-and-elevation-for.html


The link to  the men who took down and repaired this house, Green Mountain Timber Frames:  https://www.greenmountaintimberframes.com .