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Title: Plank Frame Barn Construction
Author: Shawver, John L.
Language: English
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Plank Frame Barn Construction
BY JOHN L. SHAWVER
DAVID WILLIAMS COMPANY, Publishers
232-238 William Street, New York
1904
COPYRIGHTED 1904,
BY DAVID WILLIAMS COMPANY.
PREFACE.
This matter was originally presented in the columns of _Carpentry and
Building_, in response to continued requests for information concerning
the plank frame system of construction, which for many years past has
been growing in popularity in various sections of the country, more
particularly the Central West. The author has given a great deal of
attention to the subject, having been associated with the construction
of plank frame barns for a long period, and he is, therefore, competent
to discuss the matter from the standpoint of the practical builder.
Barns of the character indicated have been extensively erected through
various sections of the West, and it is with a view of presenting
valuable data concerning the method of construction that this little
work has been compiled. In the course of his articles the author
points out the advantages of the form of construction referred to and
describes wherein there is a saving of time, labor and material, an
important consideration, especially in sections of the country where
timber for building purposes is not in plentiful supply.
Constructing a Plank Frame Barn.
BY JOHN L. SHAWVER.
The growing interest in the plank frame barn, as manifested by
inquiries which have emanated from many quarters, calls for specific
information which will enable every builder and farmer to avail himself
of the many advantages offered by this system of construction. The
system has been in use in Central Ohio for the past 20 years, and has
been rapidly growing in favor wherever people have had an opportunity
of investigating its merits. During these years the system, which was
at first somewhat crude and undeveloped, has been gradually improved,
until to-day, after many of the most severe tests, it is believed to
have reached very near perfection as regards economy of material and
labor, strength of frame, convenience of arrangement and durability of
structure. The advantages offered by this method of construction are:
1. A saving in timber of from 40 to 60 per cent.—a
not small item in many localities where timber for
building purposes has become a scarce article.
2. An opportunity to employ for the building of
barns timber that could scarcely receive consideration
if solid timber mortise and tenon frames were to be
built.
3. A saving in the cost of sawing, cutting and
hauling of about one-half of the timber.
4. A saving in cost of framing, ranging from 50 to
90 per cent., according to the plan of the building and
the efficiency of the builders.
5. In cases where farmers’ wives are expected to
board and lodge the builders, a saving in labor and
vexation of two or three weeks’ unnecessary time for
framing old style barns.
6. A riddance of practically all of the interior
timbers, which are usually an interference with the use
of the horse forks and hay slings, as well as a source
of constant vexation at threshing time and all other
times when the barn is in use.
7. The full benefit of the self supporting arch
roof, a construction of combined triangles, long braces
and perpendicular timbers.
8. Durability, arising from the fact that there are
no mortises in which moisture may accumulate and cause
the tenons to decay.
9. The strongest possible support for the track of
the hay fork or sling.
10. Ease of addition to the main building should
any ever be required.
Changes and variations in plans need cause no loss of timber, as is
certain to be the case where a bill of materials has already been
placed on the ground. If a piece of timber is too long the piece cut
off is used at some point, though perhaps not over 18 inches in length
and containing only 2 or more feet of stuff. Suppose we cut off 18
inches of an 8 × 8 we have lost 8 feet of lumber, which is worthless
for any purpose save for fire wood. If a given piece is too short it
is spliced in a moment’s time and no loss of strength is sustained. In
an old style framing if a piece was too short it required considerable
labor to remedy the matter, and a loss of both timber and strength was
sustained.
[Illustration: Fig. 1.—Interior Bent of Plain Gable Barn with Basement.]
Herewith are illustrated two bents of a barn, Fig. 1, showing a plain
gable barn with basement. Referring to it, 1 1 1 are posts of basement
bent, consisting of five 2 × 8 planks, two of which are 8 feet long
and three of which are 7 feet 2 inches. Upon these rest the joist
bearers, marked 2 2 2, which consist of three planks 2 × 10, extending
lengthwise of the barn. These basement bents are thoroughly braced by a
method which will be illustrated hereafter. The braces 3 3 3 are made
of two 2 × 4 inch stuff the required length, with a short piece of the
same material forming a clamp brace somewhat similar in shape to a
clothes pin. The sill of the superstructure, marked 4, consists of two
2 × 8 inch plank, with 6-inch space between them. The posts 5 5 are
made of two 2 × 8 inch plank, with intervening 2-inch space. The purlin
posts, 6 6, are made of two 2 × 8 inch plank, with intervening space;
7 7 are roof supports, consisting of a 2 × 8 inch plank. The collar
beams 8 are two 2 × 12 inch plank with intervening 2-inch space; 9 9
are sub-supports, made of a 2 × 6 inch plank; 10 10 are stays of two 2
× 4 inch plank, with intervening 2-inch space; 11 11 are the main ties
of one 2 × 8 inch piece; 12, 13 and 14 are braces and ties of 2 × 6
inch plank; 15 15 are purlin plates, made of two 2 × 8 inch plank, with
intervening 2-inch space into which couplings and braces enter.
[Illustration: Fig. 2.—Barn Bent, Showing Gambrel Roof Construction.]
At 16 16 the main plates, made of two 2 × 8 inch plank, are placed into
a V-trough and inverted over the top of the post. The rafters 17 17 may
be spliced on the purlin plates. The topmost intersections are bolted,
as shown by means of the dots. The upper ends of the purlin posts are
cut down 4 inches, on a line parallel with the roof supports, and again
at right angles with the first cut, forming a saddle, into which are
placed the purlin plates.
[Illustration: Fig. 3.—Outside View of End Bent of Superstructure and
Basement Bents.—Scale, 3-32 Inch to the Foot.]
[Illustration: Fig. 4.—Side View of Plank Frame Barn.—Scale, 3-32 Inch
to the Foot.]
In Fig. 2 is presented a view of an interior bent of a gambrel roof
basement barn, which is constructed on the same general principles as
shown in the previous figure. Hip roofs, gothic roofs, etc., are as
readily provided for as either gable or gambrel roofs, so any man’s
taste may be fully met in this respect.
[Illustration: Fig. 5.—Detail Showing Section of Frame.—Scale, ¼ Inch
to the Foot.]
[Illustration: Fig. 6.—Section of Purlin Plate.—Scale, ¼ Inch to the
Foot.]
An outside view of the end bent of the superstructure and an end view
of all the basement bents are shown in Fig. 3 of the illustrations. The
braces in the basement are permitted to extend up and between the sills
of the superstructure, thus binding both basement and superstructure
into one solid frame work. In the interior of the basement, where long
braces will not interfere with the arrangement or convenience, they are
to be preferred to short ones, but where short braces are necessary
they are inserted in such a manner as to give greater strength than
when mortised in as is usually done.
[Illustration: Fig. 7.—Detail at Peak of Barn.—Scale, ½ Inch to the
Foot.]
A side view of the frame, which is of such a character as to fully
explain itself, is presented in Fig. 4. The plate is made of two 2 ×
8 plank spiked together to form a trough and inverted over the tops
of the posts. The manner of constructing the bents of the basement is
indicated in Fig. 5. If the posts can stand on solid pillars of stone
no sills are necessary, and the fillers extend down to the lower ends
of the posts and up to the joist bearers. A side view of the purlin
plates, which are made of two 2 × 8 or 2 × 10 plank with a 2-inch
space between them, is shown in Fig. 6. The coupling or splicing block
extends either way from the roof support _a_ to the dotted lines _b b_.
At _c_ is represented a sectional view of the sub-support, to which
the stays _d d_ are secured, and also the lower end of the braces _e
e_. This arrangement gives sufficient strength to the purlin plates to
sustain a slate or any other roof desired. Fig. 7 shows the manner in
which the peak of the arch is constructed. The roof supports, which are
usually of 2 × 8, are indicated by A A. The sub-supports, usually of 2
× 6 plank, are indicated by B B, while the dotted lines represent the
collar beams, C, constructed of 2 × 12 inch plank, there being one on
either side and bound together by ½-inch carriage bolts 6½ inches in
length, their position being indicated by the small crosses.
[Illustration: Fig. 8.—Detail Showing Construction of Posts in End Bent
of Fig. 3.]
[Illustration: Fig. 9—Sectional View of Plate.]
Three posts of the end bent, shown in Fig. 3, are constructed of two
2 × 8 plank, one 2 × 4 and one 3 × 6, all as indicated by the cross
section in Fig. 8 of the engravings.
[Illustration: Fig. 10.—Side Elevation of Barn Having Two Driveways and
Bay at Either End.]
It will be noticed that all of this work is easily and quickly done
and that there is not only a saving in the timber, but also in the
labor. As an example of the time required to erect a frame, I would
state that I was recently called to another county to assist in
building a basement barn, 40 × 80 feet in size, 8-foot basement and
16-foot superstructure, with plain gable roof. With three carpenters we
commenced work on Wednesday morning, and on Saturday of the same week
we raised the barn complete. In other words, it took four carpenters
three days to frame a barn 40 × 80 × 24 feet.
In Fig. 10 is shown a side view of a barn with two driveways and bay
at either end. A A are duplicated on inside of posts, with bridge
blocks at dotted lines; B´ is main plate; C is purlin plate of two 2 ×
8 plank set at right angles with roof and also braced at right angles;
D is roof supports, forming the arch of the barn, and E the collar
beams. Fig. 11 shows interior bent of a “ground” barn with decks above
driveway. Should stables be desired in one or both ends joist bearers
may extend entire width of barn.
There are doubtless many who would like some evidence of the strength,
durability and popularity of this system of barn building, and I
therefore submit a few facts in relation to these points.
_First Test of Strength._—A small model made of linden strips 3-16
inch thick and ½, ⅜ and ¼ in inch width, made on a scale of ½ to 12
and representing a barn 40 × 60, with 8-foot basement and 20-foot
superstructure, was found strong enough to support four men of average
weight.
_Second Test._—Several years ago a number of persons at a barn raising
were discussing the frail appearance of the frame, and a test was made
with chains and levers in an effort to crush the frame by drawing at
opposite angles, but without the slightest effect.
[Illustration: Fig. 11.—Interior Bent of “Ground” Barn with Decks Above
Driveway.]
Another example is found in a barn which was put up with a minimum
quantity of spikes, because the owner did not wish to take time to go
to town for more. The barn has been standing 14 years, within which
time a number of destructive wind storms have passed over it without
damage, though much damage to fences, forests and buildings resulted in
the vicinity.
As evidence of the rapidity with which the framing may be done,
I will refer to a basement barn, 40 × 80, 24 feet to the square,
recently erected in Union County, Ohio. I began with three carpenters
on Wednesday morning, and on Saturday of the same week the barn was
raised complete. We were compelled to work under the disadvantages of
considerable mud on the newly graded foundation site, necessity of
carrying the timber some distance, and the short days in mid November.
None of the hands had any previous experience in this work, so had to
learn as they proceeded.
A large dairy barn was built the last week of October, 1896, just out
of New York City. It is 100 × 36, with 8-foot basement and 16-foot
superstructure. We had four house carpenters and two laborers. Began
work Monday morning, but were delayed by the non-arrival of the spikes
till nearly noon. The basement bents were each 100 feet in length,
and there were nine bents in the superstructure. Both basement and
superstructure were raised on Friday of same week in six hours with the
help of 30 men.
Still another example may be given to show the difference between the
plank frame and the mortise and tenon frame. With three helpers I
framed a barn, 40 × 72, with 20-foot posts, while two carpenters, one
of them a foreman, framed the sills for a corn crib, 5 × 40.
The system has been introduced into 32 States and some fair sized
barns have been built in this way. One in Kentucky, 56 × 100; one in
Colorado, 60 × 70; one in Wisconsin, 40 × 120, with wing 40 × 60; one
in Ontario, 56 × 96, and one in Virginia, 60 × 100. I have yet to learn
of any who, having built strictly to specifications, are dissatisfied
with the frame. On the contrary, we are frequently in receipt of
letters from those who have thus built stating that they are delighted
not only because they have saved both money and timber, but at the same
time have obtained a thoroughly strong frame without the usual interior
timbers, which are so much in the way in handling hay or grain.
I shall be glad to have the friendly criticism of practical builders
given in the columns of _Carpentry and Building_. Any suggestions which
may lead to further improvements in the system will be appreciated
very much, and due credit will be given to those who suggest them. It
will be seen that the system is especially adapted to large grain and
hay barns, to cover barnyards, which are becoming so popular in many
sections of the country, to tool sheds, tobacco barns, amphitheaters,
&c.
While there is not so large a saving in the timber of the basement as
in the superstructure, there is yet a fair saving of timber even here,
and at the same time there is great saving of labor. The timbers are
employed only where they can serve a useful purpose, and special effort
is made to so place the timbers as to secure the maximum amount of
strength with the smallest possible amount of timber.
* * * * *
The following communications were brought out as the result of Mr.
Shawver’s invitation to the readers of _Carpentry and Building_:
Bracing a Basement Barn Built on the Plank Frame System.
_From_ E. S. H., _Connecticut_.—I have been reading the articles of
Mr. Shawver on barn framing with a great deal of interest, and I am
desirous of obtaining full instructions in regard to bracing the
interior of a basement barn: also a complete bill of materials for
the frame of such a barn, 40 × 60 feet in area, basement 8 feet high
and superstructure 20 feet high. The roof is of the gable pattern,
one-third pitch. There is also a bay in each end and a double driveway.
_Answer._—In referring to the above inquiry, Mr. Shawver submits the
following information, accompanied by the illustrations presented
herewith: The sketches here given will explain in detail the manner of
inserting the braces and the way in which they are made. Of course,
when long braces will not interfere with the desired use of the space
they are preferred to short ones, but short ones properly inserted
will give the same rigidity to the plank frame that braces of similar
length will give to a mortise and tenon frame. The braces C C of Fig. 1
are inserted in the bents as the latter are constructed, but the brace
shown in Fig. 2 is not inserted until the barn is raised.
In basement barns the joist bearer, A of Fig. 1, is made to extend
lengthwise of the building, and the bents of the superstructure being
placed crosswise we find the sill of a bent of a superstructure as
represented at F F. But in ground barns the joist bearers extend
crosswise of the barn, and the post B is permitted to extend up
through the joist bearer about 7 inches. Two posts are then spiked to
this projecting portion, one on either side, and thus again the brace
shown in Fig. 2 may be inserted if thought necessary. If, however, the
braces are properly inserted in the side walls of the frame the short
braces may safely be omitted in ground barns.
[Illustration: Fig. 1.—Showing Method of Bracing.]
[Illustration: Fig. 2.—One Form of Brace Employed.]
The following is a bill of materials for a plank frame basement
barn, 36 × 60 feet, basement 8 feet, with wall on one side, 16-foot
superstructure, with a 23-foot bay at each end and a 14-foot driveway
in the middle. Roof one-third pitch, plain gable, decks over driveway
if permissible. Interior posts of basement to stand on stone pillars.
BILL OF MATERIALS.
Basement: First Bent.
Ins. Ins. Ft.
2 sills 2 × 8 × 60
(or six 2 × 8 × 20)
12 posts 2 × 8 × 8
4 door posts 2 × 6 × 8
6 post fillers 2 × 8 × 8
4 nailers 2 × 6 × 12
1 nailer 2 × 6 × 14
3 joist bearers 2 × 10 × 60
(may use 14s and 24s.)
10 braces 2 × 6 × 10
Bents 2, 3 and 4 similar.
12 posts 2 × 8 × 8
18 post fillers 2 × 8 × 8
20 braces 2 × 4 × 6
3 joist bearers 2 × 10 × 60
Ends of Basement.
8 sills 2 × 8 × 9
(or four 2 × 8 × 18)
4 nailers 2 × 6 × 18
(or eight 2 × 8 × 9)
4 nailers 2 × 8 × 18
16 braces 2 × 6 × 10
56 braces 2 × 4 × 6
28 brace blocks 2 × 4 × 16
Superstructure: Two End Bents.
4 sills 2 × 8 × 36
(or eight 2 × 8 × 18)
12 nailers 2 × 6 × 18
4 beams 2 × 8 × 36
(or eight 2 × 8 × 18)
20 posts 2 × 8 × 16
10 post fillers 2 × 4 × 16
8 braces 2 × 6 × 18
8 purlin posts 2 × 8 × 8
8 braces 2 × 4 × 9
2 gable ties 2 × 6 × 18
6 stiffeners 3 × 6 × 16
Two Interior Bents.
4 sills 2 × 8 × 36
(or eight 2 × 8 × 18)
4 sills 2 × 8 × 2
8 posts 2 × 8 × 16
8 purlin posts 2 × 8 × 24
(or twelve 2 × 8 × 16)
4 roof supports 2 × 8 × 22
4 sub-supports 2 × 6 × 17
4 collar braces 2 × 12 × 5
8 stays 2 × 4 × 3
4 ties 2 × 8 × 8
4 ties 2 × 6 × 5
4 ties 2 × 6 × 4
4 braces 2 × 6 × 8
Two Floor Bents.
4 sills 2 × 8 × 36
(or eight 2 × 8 × 18)
4 sills 2 × 8 × 2
8 posts 2 × 8 × 16
8 purlin posts 2 × 8 × 24
4 roof supports 2 × 8 × 22
4 sub-supports 2 × 6 × 17
4 collar braces 2 × 12 × 5
8 stays 2 × 4 × 3
4 ties 2 × 8 × 8
4 ties 2 × 6 × 5
4 ties 2 × 6 × 4
4 braces 2 × 6 × 9
8 joist bearers 2 × 8 × 8
Side Timbers.
4 sills 2 × 8 × 23
2 sills 2 × 8 × 14
24 nailers 2 × 6 × 12
4 nailers 2 × 8 × 14
8 plates 2 × 8 × 23
4 plates 2 × 8 × 14
8 purlins 2 × 8 × 23
4 purlins 2 × 8 × 14
8 couplings 2 × 8 × 8
4 couplings 2 × 8 × 4
4 braces 2 × 4 × 12
16 braces 2 × 4 × 7
8 deck joist 2 × 8 × 14
Floors, siding, roofing, doors, etc., will be the same as in other
barns of same dimensions.
ESTIMATED COST OF FRAMING.
Foreman, $2.50 per day, 3 days $7.50
Two journeymen, $2 per day, 3 days 6.00
Two apprentices, $1.25 per day, 3 days 3.75
—————
Total $17.25
Raising and inserting braces, 1 day 5.75
—————
Total $23.00
Cost of completing same as other barns of same dimensions and style of
finish.
A Plank Frame Applied to a Skating Rink.
_From_ N. B., _Sussex, N. B._—We want to erect an auditorium, 50 × 200,
with 16-foot posts and 12-foot sheds at each side for offices, waiting
rooms, saloon, etc. We want galleries all around and a large band stand
at one end, suspended from the roof. The building is to be used for
a skating rink in winter and for public meetings during the summer.
Will the plank frame system described in _Carpentry and Building_ be
suitable for the frame?
_Answer._—The above inquiry was submitted to Mr. Shawver, who
contributed the recent articles on plank frame construction, and in
reply he says:
The plank frame is admirably adapted to such a building as that
described, and can be quite cheaply constructed. In Fig. 1 of the
sketches is shown one of the bents near the end on which the band stand
is located, indicating the manner in which it is suspended from the
roof by the rods A A, together with truss rod B. The galleries appear
at either side, above which and beneath the eaves are the windows. If
lighted by dormer windows, or if artificial light is employed, the shed
roofs may be of the same pitch and a continuation of the roof of the
main building, in which case the galleries may extend back beneath the
roof of the sheds, and they need not extend out further than the purlin
posts. The sketch, Fig. 2, shows an interior bent without the band
stand. The end bents will be constructed in a manner similar to that
shown in Figs. 1 and 2 of my article on plank frame barns. A 200-foot
building should have 17 bents placed 12½ feet apart.
[Illustration: Fig. 1.—Bent Near the Band Stand.]
[Illustration: Fig. 2.—An Interior Bent.]
Construction of Plank Frame Basement Barn.
[Illustration: Basement Plan.—Scale, 1-16 Inch to the Foot.]
_From_ S. H., _Minneapolis, Minn._—I would like to have the readers
experienced in plank frame barn construction comment upon the plans
of the basement barn which I send herewith and from which I intend
to build next summer. I would like very much to know the weak points
of the barn and the best way to remedy them. I think the drawings
showing the plans and details are so clear as to practically explain
themselves.
[Illustration: Elevation of Front Framing of Barn.—Scale, ⅛ Inch to the
Foot.
_Construction of Plank Frame Basement Barn.—Floor Plans.—Scale, 1-16
Inch to the Foot._]
[Illustration: Main Floor.—Scale, 1-16 Inch to the Foot.]
Criticism of Plank Frame Barn Construction.
_From_ JOHN L. SHAWVER, _Bellefontaine, Ohio_.—In response to the wish
of “S. H.,” Minneapolis, Minn., I offer a few suggestions in connection
with his proposed plank frame basement barn. It is well, indeed, that
he should insist on knowing what he is doing, for many have made
blunders because they attempted to build plank frames without having
first investigated the proper method of construction. Too many guess
at it. As pioneers in this work, we started, 25 years ago, on small
structures, and month by month studied and contrived until a system was
evolved that is adapted to barn structures of any reasonable size.
Each point has been carefully tested as we proceeded, and if not fully
satisfactory was discarded for something better. We now have over 7000
structures in some 44 States and provinces, some of them quite large,
and have received many gratifying testimonials as to their strength,
durability and cheapness.
The floor plans submitted by “S. H.” are very good in design and
arrangement, save that the hay chutes are made to appear directly over
one of the main girders. Of course, this he would discover and rectify.
Should it be difficult to obtain 8 × 8 stuff for posts and 8 × 10 for
girders, the former may very easily be constructed of two 2 × 8’s and
two 2 × 4’s, box pattern, thus saving something in materials and risk
from dry rot. The girders might be made of two 4 × 10’s, or four 2 ×
10’s, leaving an air space of 2 inches in the middle and saving the
necessity of making mortises.
The drawings indicate the use of two 2 × 12’s and one 2 × 8 for cross
sills, the 2 × 8 being flat. In my opinion, the 2 × 8 is needless. The
plates are all flatwise, while they must sustain much weight. We prefer
purlin plates set on edge at right angles with the combined pressure
of both sets of rafters. The main plates we make of three 2 × 6 inch,
or 2 × 8 inch, according to the size of the structure when on edge to
sustain the weight and two to sustain the outward pressure of the roof
and the contents of the building. In this case, the purlins should
incline 45 degrees.
The drawings of the correspondent indicate that the nailers are cut to
fit between the posts, in which case they must be mortised, gained or
toe nailed. The first two require unnecessary work, while the latter
is not strong enough. If the bents are constructed in three sections,
they will be tedious to raise in position. If completed before
raising, they will be weak at the purlin plate. The drawings indicate
also that staging would be required in setting the upper frame, and
that quite a large amount of the work is done as the frame is being
raised. In our experience we never use any staging, and we do most of
the work from the ground before beginning to set for the frame. Most
men can work more rapidly on the ground, with all materials handy,
than they can aloft, where materials must be drawn up with ropes. I
believe “S. H.” can save enough on labor alone to pay his expenses
to go to some point and see one of our plank frame constructions.
Besides, he will find wherein he can greatly improve upon his method
of construction. Those who are within convenient reach to do so can
visit the barn of Dr. W. I. Chamberlain, near Cleveland, Ohio, which
is easily accessible by railroad, while the doctor, who is one of the
editors of the _Ohio Farmer_, takes great delight in showing his barn
to visitors. This barn, which is 40 × 82 feet in size, required four
carpenters two and a half days to frame and two hours and fifteen
minutes to raise.
We do not usually give name and address of our patrons, because it
leads to much inconvenience to them. Should any of the readers write to
Dr. Chamberlain, I would suggest that they inclose a stamped envelope,
properly addressed, for reply.
Criticism of Plank Frame Barn Construction.
_From_ J. M. B., _Monroeton, Pa._—In the December issue of _Carpentry
and Building_, page 327, the correspondent “S. H.” of Minneapolis
wants to know the weak points of his barn frame, a sketch of which was
presented in connection with his communication. I think one weak point
is what he calls the plate in the gable, which is made of two 2 × 8
inch pieces, equal to a 4 × 8 inch, with a span of at least 30 feet
between purlin posts, which are only 2 × 6 inches. In my opinion, with
the hay mow filled with hay, the gable will bulge or spring out, as the
weight, 45 to 50 tons, will exert quite a pressure. As to the remedy I
am not so clear. He might use a flat truss or a beam large enough to
stand the pressure; one, say, 16 inches wide at the center and tapering
to 8 inches at each end. I will say, in conclusion, that I have had no
experience with plank frames.
Is the Barn Frame of Sufficient Strength?
_From_ C. G., _Vergennes, Vt._—I send herewith a rough sketch of bent
of barn which I intend to put up in the spring. It is 30 feet wide and
has 26-foot posts. What I wish to know is this: Is the truss strong
enough to carry the load that will be put upon it? I would like to have
the “wood butchers” take hold of it and tear it apart and tell me what
to put in its place.
_From_ JOHN L. SHAWVER, _Bellefontaine, Ohio_.—Permit me to offer
a substitute for the barn frame proposed by the correspondent “C.
G.” of Vergennes, Vt., in the March issue of the paper. His timber
trusses take up too much room, and at the same time the timbers are
too expensive for this day and age. We place a little more timber in
the joist bearer and prefer it in a different shape. He suggests 7 ×
8 inches, and this would be 30 feet in length. We would use three 2
× 10’s, and could use any lengths to make the 30 feet; consequently
our timbers could be purchased at much less cost. Instead of the 7 ×
8 inch truss timbers we would use two wire cables made of galvanized
wire, seven strands, and doubled. While we would use a little heavier
posts in the stables, the posts of the superstructure would contain
only about one-half as much material, but this, too, we would prefer of
different shape. In place of the 7 × 8 inch we would use two 2 × 8’s,
and instead of the beam we would prefer the arch and the angling purlin
posts, and thus have the interior entirely free from all timbers.
[Illustration: Is the Barn Frame of Sufficient Strength?]
After 20 years’ experience in building barns without the cross beams
it would require peculiar conditions to induce us to use them, for
they are continuously in the way, both when storing away hay or grain
and when getting these out again for the thresher or for the feeding
of stock. The upper portion of the frame submitted by “C. G.” does
not show any braces, and we are at a loss to know if there is to be
none, or if these were omitted because it is not that portion of the
structure that is under consideration. Let me say, however, that that
is one of the most prevalent mistakes in the construction of a barn.
There are too few braces, and the first baby tornado that happens to
pass that way will “lay it out in fine shape.” While we use plenty of
braces, they are usually only 2 × 6 inches, and so do not take timber
very rapidly. The geometrical triangle is the strongest figure one can
secure, and it is with that idea always in mind that we do our barn
work.
Bents for 12-Sided Plank Frame Barn.
_From_ J. D., _Ubly, Mich._—I send herewith a rough sketch, Fig. 1,
showing one of the bents of a 12-sided plank frame barn, and would like
to have the architectural readers of the paper state whether or not it
will be strong enough for the purpose, and, if not, wherein changes can
be made to advantage.
_Note._—With a view to obtaining the opinion
of an expert who has had long experience in the
construction of plank frame barns, we submitted the
inquiry of our correspondent above to John L. Shawver,
who furnishes the following in reply:
In the first place, the purlin posts in the sketch of the correspondent
are so sloping that while they brace well they are not in position to
sustain the most weight, and these with the roof supports are so long
that they have to be spliced. While this is easily done in the case of
posts, it is not so readily performed with supports, and, when so done,
it will not present as attractive an appearance as would otherwise be
the case.
[Illustration: Fig. 1.—Elevation of Bent Submitted by “J. D.”]
[Illustration: Fig. 2.—One Form of Plank Frame Suggested by Mr.
Shawver.]
In the second place, one of the weakest points about the barn is the
shape. It is true it would be a novelty in most communities, but, like
the round barns, is wasteful of material. It is out of the question
to place joists, rafters, flooring, sheathing, roofing, &c., on barns
of this shape without much waste of both materials and labor. Then,
too, it is next to impossible to provide for satisfactory lighting or
ventilation, both of which are essential features in every up to date
barn.
[Illustration: Fig. 3.—The Preferable Style of Framing.]
The frame construction indicated in Fig. 2 is stronger, and at the
same time gives more open space in the interior, this being secured by
running the purlin posts up to the first purlin plate, instead of to
the second, and supporting the second plate on the truss brace. This
saves in the lengths of the purlin posts, but requires the same length
of supports and longer sub-supports.
The form of construction indicated in Fig. 3 is, in my opinion,
preferable to either of the others, if it is found that the vertical
posts set in 10 feet will not in any way interfere with the purpose
of the structure. In this case all the timbers are either shortened
or placed in such shape that they may be spliced without in any
way weakening the structure. Whichever form may be used by the
correspondent, it is important in bents or arches of this size that
the purlin posts should be placed on the inner edge with 2 × 6, which
will add materially to the strength of the frame, and at the same time
prevent any tendency to spring sideways either in the raising or from
the pressure of the hay or grain within after the building is completed.
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