Baring the bones of a house: The Cobb- Hepburn House

The Cobb- Hepburn House is coming down.

Luckily it will be saved and reused.

I was there to measure and record.






The house suited its site. It was "built to the weather".

Set on a foothill ridge with fields sloping off on all sides, it had good drainage all around.

It faced east and looked south to the road, the view, and the sun. The parlor was in that sunny front corner. Deciduous trees just beyond let in winter sunshine, shaded the house in summer.

The wind here comes from the west and the south, The house was backed up against the mountain to the west, sheltered by it, below the wind coming over the ridge. The kitchen and its door were on the north end. An orchard to the southwest scattered the wind's force.

The family had died out; the land sold to the farmer who lives next door.
His daughter didn't want to live in the house.


It wasn't built for our modern era and it had not been cared for.


The entry hall is 4 feet deep, almost too small for 2 people to pass; certainly too small to welcome visitors.
The stair is 30 inches wide, and steep.
The only bathroom is on the first floor off the kitchen.

The bedrooms are only accessible through each other.

One door was mounted upside down, including the latch. Was it a quick fix - 100 years ago? - so the door would swing the right way?

Except for electric wires stapled to the walls and some interior storm windows the house hasn't been updated since the 1950's.

I was there to record its layout and proportions, to record how the builder used the materials he had: wood, plaster, nails, some iron, marble, stone, and glass.
It was cold - 5*F when I began measuring in the morning, about 15*F when I left mid-afternoon: not ideal for exposed fingers.The crew needed me to measure so they could continue dismantling, so I kept my hand warm with a propane heater. I photographed the rooms as an auxiliary record.

I have been back several times. The temperature has never been above 20*F at 2pm in the sun.






The crew is knowledgeable, experienced and interested. We share what we find and what we know, what we wonder about. We measure together.They need accurate dimensions to repair the frame for reconstruction.

2 kinds of scribe marks and offset marks are clearly visible. The 'B' on the post and beam are one pair of many.

The frame seems to have been built several years before the second floor ceiling joists - cut by a saw mill, laid out in a different pattern - were installed. Other joists were moved to allow space for the stair.
A third fireplace and another exterior door (frame and door!) were found under layers of wallpaper.
The 1st floor sheathing on the front facade had been replaced with plywood. One bedroom had not been finished until cast iron stoves were in use, 40+ years after the house was framed.

The videos are by Dan McKeen of Green Mountain Timber Frames. http://www.greenmountaintimberframes.com

                                      
  

A barn built in the 1830's

Green Mountain Timber Frames http://www.greenmountaintimberframes.com/ measured this barn before they dismantled it to use its frame anew.

Due to the wood used - poplar, beech, hemlock - the layout and the construction we think this barn was built by a farmer without an extensive background in framing. We think it dates to the  1830's.

 The floor was dirt, the head room under the hay loft not quite 6 ft.
What was it used for? Sheep perhaps? Sheds, windows and a silo were added over the last 180 years, making the original purpose hard to read.


I start with the farmer.
He had some wood of a certain size and length he could use for posts and beams for a barn. He knew how the barn would be used and where it would go.

Probably he had a carpenter square - they were readily available. But maybe not, as his dimensions don't quite fit. And he was much more comfortable with the old-fashioned geometry of the 'whirling square'.

He started with the width - 18 feet. He made a square: 18 ft wide, 18 ft. high - first diagram.\
Or so it seems. Today that height is 17'-10", 2". I think originally the width was also 17'-10". His inch seems to have been just a bit smaller than today's inch

He could have started with a string about 18 ft. long. He could have used a compass with a 27" radius, stepped it out twice for 4'-6", twice more for 9' and doubled that for 18'; or a pole 4'-6" long.

In his square he laid out his center lines and then the star that joins the points - the second and third diagrams. This is a medieval framing system which came to New England with the English colonists.

I have added circles to mark how the lines of the star cross at the locations of the girts, I've added a green dashed line to show how the height of the wall is 2/3 the height of the end wall. Almost. It's off by 2"

Using a carpenter square to layout a 3/4/5 triangle does not work as well. The wall height isn't high enough. The lower girt can be determined - see the green circles - but not the upper one.

While the frame appears governed by the traditional English framing geometry, the frame itself has dropped girts - a Dutch traditional way of framing. The girts are mortised into the posts below the upper beam. This combination of framing methods is sometimes referred to as 'American'.


The floor plan is simple: three 3/4/5 triangles. If the width is 18'  the length should be 40'-6" . It was 40'-2" measured on site. The men repairing the frame tell me it is 40'-1"; that the 2 interior bents are at 13'-4 1/2" from each end.

If one arm of the 3/4/5 triangle is 17'-10", the other is 13'-4 1/2".
3/4 of one side of a 17'-10" square = 13'-4 1/2". So either framing system fits the floor plan.

Dan McKeen, GM Timber Frames, also tell me 3 girts are beech, one poplar.The top plates are poplar and in good shape. The posts are sawn hemlock and hewn beech. The ties are sawn hemlock.

I looked at how did this farmer/framer laid out his girts in the side walls.
Here I tried - on the right in red - 3/4/5 triangles. The intersections - red circles - using a triangle that includes the rafter tails, are close, but convoluted. Not simple.
However, a square laid out inside the frame - on the left in green - neatly divides the space in thirds - green circles.

The star of the square used for the gable end laid out along the side also notes the placement of all the  girts.








The numbers on the early carpenter squares were engraved by hand. It is possible that this farmer/framer owned a square that was very slightly off. Or he used his own measure.

The man who built this frame comes alive as I study it; I've met him. Now I want to ask how he learned to frame - who taught him? what tools did he like? where did he start? were we right about his choice of materials?

House to save!

WHOM  do you know  who is just yearning for a c. 1780 western  Vermont farmhouse with a pristine post and beam frame?
The house itself is quite plain inside, fitting to its time and place. There are few parts to salvage beyond the frame. perhaps the clapboard and brick, doors and hinges. The window sash are c. 1900 or later.

HOWEVER:The frame is chestnut with gunstock posts. It could be exposed to the roof if an owner wanted.

http://blog.greenmountaintimberframes.com/2014/12/27/demolition-is-just-days-away-save-this-tinmouth-vt-barn-home/

I will be measuring and analyzing this house on Monday - if the roads from here to there aren't too icy.

More later after I have dimensions.
.

Geometry of a Hartford, NY barn, c.1790

A Hartford, New York, barn was carefully dismantled for reuse this fall by Green Mountain Timber Framers.

I was there and later analysed the timber frame. Dan McKeen, owner of Green Mountain TF asked me to write a guest blog on the geometry of  the barn for his website.
I wrote about the basic layout, how it was developed from just one dimension, the width of the barn.

To read that post use this link:

 http://blog.greenmountaintimberframes.com/2014/12/04/geometry-in-historical-frames-a-guest-blog/ 

Here are two more diagrams that continue the exploration of the geometry.

The section is the measured drawing of the end of the barn seen above.

I found that the mortises in all the posts (the mortises hold the tendons of the rails) were all cut in the same pattern. 

The arc the framer used to locate the intermediate lefthand post also located the upper horizontal rail.

The diagonal intersecting the arc of the length of the square can be easily rotated so that it marks a horizontal line instead of a vertical one.

The framer then turned his compass and swung an arc from lower right to upper left. The intersection of the diagonal and arc became the location for the lower rail. (See the green circles!)

All the rails for the barn are located at the same heights on the posts. This means the framer could set up one jig to cut all the mortises - simplifying his job, getting the work done faster. And  a bit of mass production, ie: a precursor to square rule framing. 

There is also the roof layout.  I have not yet drawn the diagrams. 

Be awestruck with me! Full of wonder!  

Old First Church Geometry, the Elevations - Part 3

This is part of a series on the geometry of the Old First Church (OFC). Bennington, Vermont.



I began looking at the geometry of the church in 2012 beginning with the  'rolling circle' muntin pattern in the rounded tops of the windows.









I found that the repetition of the circle I saw in the windows was used in the window and column placement of the side elevations. The length of the sanctuary is also governed by the repeating circles.

The circle divided into its 6 parts - the daisy wheel - defines the church's width and height and its roof.



These drawings I have already discussed in the earlier posts.  

Now for the new ones,





The daisy wheel rotated 30*, or with a horizontal axis instead of a vertical one, the line between the 'petals' defines the column placement - the outer side of the columns.
The diagram below shows how the same proportions - the main nave of the church and it's side aisles can be laid out by locating the circles 90* instead of 60* to each other ( 4 petals on the daisy instead of 6).






The front elevation of the church is governed by the same circle.
Then the first circle's center is the bottom point of the diameter the second circle. The second circle's center is the bottom point of the third circle's diameter. The 3 circles together encompass the church and its tower.
They lay out
1) the height and width of the church meeting space
2) the height of the first 2 levels of the tower
3) the location of the Palladian window in the tower

If the center of the middle circle is used as the outer edge for parallel circles on either side, the 4 petals that result determine 4) the size of the protrusion of the narthex - and the location of the columns inside,
5) the location of the bottom chord of the pediment,
6) the placement of the bell platform
7) the height of the architrave above the columns and their arches that surround the bell.

I have drawn the diagonals of the bottom circle in green which mark the rectangle of the church body. Note how it determines the roof of the main door. I have added dashed red lines at the sides of the extended narthex ('porch')  and extended those lines up to meet with the line marking the top of the belfry.


Here is the diagram of circles extending both horizontally and vertically, creating squares instead of daisy wheels. It's just a reminder. 
I've laid out its construction in earlier posts.
http://www.jgrarchitect.com/2014/09/how-to-construct-square.html














Lastly, here are the circles in the same rhythm as those which determine the pattern in the windows.

(1) The first red circle at the bottom encompasses the church. Its center is at the top of the pediment over the main door.
(2) The second red circle sits on the center of the first. Its center is the Palladian window in the tower.
(3) The green circle's center is on the line laid out by where the first 2 circles cross which is also the peak of the oerdiment over the 2nd floor Palladian window. It extends from the floor of the church to the  rail of the belfry.

The circles can 'roll', just as does the muntin pattern of the windows.
 Here are some of the circles that grow of the 3 laid out above. Each circle's location is determined by those on either side.
The centers are noted with small red circles. Note that they determine important features of the facade.

The circles themselves were numbered in green - visually it was too confusing.


 There are many points I have not called out. It is just clutter at this small scale. Remember that pictures can be enlarged by clicking.

Timber frame from a carriage house

Green Mountain Timber Frames of Middletown Springs, Vermont, http://www.greenmountaintimberframes.com/
erected this 17 ft. by 26 ft. frame in their workshop.
Originally a carriage house, it had last been used as a garage and was for sale.

I asked Dan McKeen if I could visit and watch his crew work. I learn a lot from watching.
Dan welcome me, give me a tour, let me watch, and was happy to have me  measure this frame.
I measured both sides but only made notes on the rest.The ridge is 5 sided, the rafters are 36"o.c. The pitch? I don't know.The front and rear sides were not assembled. There was no sill.


I noted that the length and height of each side was almost equal, about 2" off; that the braces were set at 45* and that the cross beams though different sizes were set at the same height. I wondered if it had been laid out from the foundation or from the sill, as I have seen both.

The date of construction was c.1840. Based on the date I tried a 3/4/5 triangle layout. Even when I allowed for the sill it was not successful. Nothing lined up nor gave the framer any information.

The frame itself said, 'Square'. It also said 'Simple', not a tour d'force. I tried squares.



The square which begins on the outside of the bent and ends on the center post works. It and its star divide the square into thirds - red dashed lines -, locate the braces  and the top of the cross beam - red circles.

After the square was laid out snapped lines on a framing floor would have laid out the star.  6 of the lines of the star - noted here in solid red lines - mark the important intersections. They divide the upper half of the square into thirds and cross at the top of the cross beam.

The frame sold before I could return to check the pitch, the front and the back.  I had measured the mortises in the end posts which were for the front and rear walls. They are drawn on the right post.



The same square determines their locations. Here I have extended a green dashed line from the intersections of the star (green circles) to the placement of the mortises.

The 5 sided ridge and the use of the square lead me to think the carriage shed was built before 1820 or that the framer was using old-fashioned methods and did not own a 'new fangled' carpenter square.


 My earlier posts show how to layout a square - http://www.jgrarchitect.com/2014/09/how-to-construct-square.html -
and how to divide the square into thirds and the ensuing star -  http://www.jgrarchitect.com/2014/04/sandown-meeting-house-revisited.html.

The cobbler's house north of Boston, c. 1840. Part 4 of 4

Organizing my drawings and thoughts for  presentation has required me to revisit earlier ideas. So here is how I now think this simple house may have been designed.  




Here is a new post on this house, built north of Boston in the Merrimack watershed c. 1840. The previous posts include its history.





First: the geometry of the 3/4/5 triangle:

A triangle by definition has 3 legs. If the legs are in proportion to each other so that the shortest is 3 units, the middle one is 4 units and the longest is 5 units. the triangle will always be shaped like the diagram here - with the 2 shorter sides meeting at a 90*, the longer side always the hypotenuse.

A 90*, a right angle, is what carpenters and brick layers need - a   way to be sure they are erecting a stable shape that in construction will keep the loads directly over their bases and transfer those load to the ground.

The wide spread availability of carpenter squares after 1820 in the United States made the 3/4/5 triangle the easy and flexible choice for layout. 2 triangles with their hypotenuses side by side made a rectangle. The long and short sides of the triangle could be flipped.


Here in the floor plan of the  cobbler's house, The right side, the main house, is 2 rectangles made up of 3/4/5 triangles. (A) is the triangle laid out. (B) is 2 triangles turned - one starts from one corner, the other from the opposite. Where they cross is the center of the rectangle. The back wing is one 3/4/5 rectangle and a little more, The size of the 'little more' (C) is  determined by the 3/4/5 ratio.

The rectangles of the 3/4/5 triangle can be set side by side, as they are here, or they can be slide past each other as can be seen in the diagram.









Here is the side elevation of the cobbler's house - a 3/4/5 rectangle with 2 more for the roof - arranged much as was the floor plan of the house. (A) is the main box, (B) is the 2 triangles set back to back.

 Add the lines for the other triangles - the diagonals for the rectangle.Where the lines cross determines the placement of the 2nd floor beam and joist (dash and dotted lines above central 1st fl. window).
The intersections also mark the center of the house, thus where the 1st floor window goes, as well as the spacing between the 2nd floor windows.






The first drawing assumed the width of the house was the '4 units' of the triangle, that the height was '3 units'. If the height is seen as '4 units', the resulting triangles cross below the 1st fl. window, That space where they cross is the width of the window.

Here it is clear that the numerical length of the unit does not matter.
The relationship between the lengths, their ratio, is what determines the layout.





What happens on the front of the house?
The front elevation is made up of 2 squares. However, the layout of the door and windows does not come from those proportions.
It comes from the use of the 3/4/5 triangles - with the wall height '3 units'.  The 3/4/5 rectangles, begun on each end of the elevation cross in the middle. Their edges place the windows on either side of the door.

Lay out the rectangles (drawn here on the left side): the diagonals cross on the center of first windows.
Swing the triangle to its other leg (drawn here on the right side): the resulting rectangle's diagonals cross at the edge of the outer windows and mark where to place the window jambs of the inner windows.







January 2020: 5 years after I wrote this I think I should check the geometry once more. If the layout of the frame began at the sills  - as I have often found - the geometry is simpler.




Originally I thought that the geometry determined the design, I now think the geometry was used for the framing. The design came from the frame. These vernacular houses did not have an 'architect' but instead a master carpenter. While I am sure they thought about what a house looked like, they were builders, not draftsmen.
These houses resonate with us because we sense the geometry which relates all the pieces to the whole.