40x100 Hay Barn

Quantities, not prices, are publishable here: roof cladding runs 4,216 square feet — 5% above the 4,000-square-foot floor at a 4:12 pitch — with 61.7 cubic yards of nominal slab beneath it. The count of working positions, not the headline area, is the figure that survives contact with the operation.

A long simple shell with one open end is inexpensive per square foot, so the cost argument in a deep store is about the apron and the approach rather than the building.

• eave height set by handling clearance above the stack
• how many sides remain open
• the apron the loader and trailers use
• roof drainage over an open working face

This page is ordered around height and clearance, because at 40x100 the 16-foot eave limits a hay barn sooner than the plan does.

3 rows fit across the 40-foot width with only 1 feet left over, which is a tight fit: the width is fully committed and nothing can be widened later without moving a wall.

Commitment first: 78% of the 4,000 square feet goes to rows at 260 square feet each, and 500 square feet survives as edge strip. A footprint is worth its own decision when that split lands where the work does. A wider bay is a structural decision and a longer bay is a layout decision; the two are often confused.

A 40 by 100 footprint is a long corridor of a plan: 4,000 sq ft enclosed by 280 ft of wall, at a 2.5:1 length-to-width proportion. Along its 100 ft dimension it takes 5 runs of rows at 20 ft, leaving 0 ft over — the 0 ft is where the argument about this size actually happens. Depth is the cheapest storage and the most expensive retrieval. A deep row holds a great deal for its floor area, but everything behind the front face is committed until the face has moved, so the plan is really a decision about how much forage can be locked away for a season. Rodents and birds treat a forage store as habitat, and the eave and base details are where that is addressed.

This footprint is planned as a deep-row store where bales are stacked in long runs back from a single face. The longest internal travel on a 40 by 100 plan is about 108 ft corner to corner, and the shortest useful one is the 40 ft cross-run. For a a deep-row store where bales are stacked in long runs back from a single face that matters where deep row forage storage sits, because shortening the 40 ft run to serve it lengthens every trip along the 100 ft dimension. The apron outside carries as much of the operation as the floor inside; in a wet harvest it decides whether filling continues.

The stored configuration carries a 16-foot eave and computes to 22.7 feet at the ridge on a 4:12 pitch — a 6.7-foot rise across 40 feet. Height is therefore not uniform, and the sidewall is the constraint. Noise from this floor reaches the office, the neighbours and the yard, and separation is a plan decision.

Height in a deep-row store multiplies across the whole run, which makes it more valuable here than in any other arrangement. It is bounded by lifting reach and by how stable a stack of that material remains as it is drawn down.

Ventilation across 4,000 square feet at this height: airflow through a stack is the reason many hay barns stay open-sided; enclosing them changes how the stored crop behaves.

The storage arrangement this floor tends toward in a heavy season is a wide-face store where most of the stack is reachable from the outside: the face has no covered strip, so anything staged in front of the stack is exposed and has to be moved the same day. Rows run the length of the building with the aisle at the open end rather than through the middle. A central aisle looks efficient on paper and costs two faces of stack that would otherwise be solid.

Depth arithmetic leaves a working end zone here. 400 square feet sits past the last row, which is why 40x100 tends to be planned with a turning bay at the open end deep enough for a loader to swing without reversing the full length of a row designed in rather than added later. Service routes are cheap to plan now and expensive to retrofit through a finished shell.

Width is fully committed at 40x100. With 1 feet spare, wall storage and passing room compete with the rows directly. Every foot of width added multiplies through the roof and the frame; every foot of length mostly adds skin.

The longest internal travel on a 40 by 100 plan is about 108 ft corner to corner, and the shortest useful one is the 40 ft cross-run. For a a deep-row store where bales are stacked in long runs back from a single face that matters where deep row forage storage sits, because shortening the 40 ft run to serve it lengthens every trip along the 100 ft dimension. The apron outside carries as much of the operation as the floor inside; in a wet harvest it decides whether filling continues. That movement pattern, not the 4,000-square-foot total, is what decides whether the leftover 10 feet is useful here.

At 40 feet the gable will not comfortably take one opening per row: 3 positions with 1 feet spare leaves too little wall for piers. A single wider opening, or a sidewall opening, is the workable route. Temperature swing on a steel shell drives condensation decisions that outrank most layout preferences.

The 40 ft ends and the 100 ft sides offer very different opening budgets: 40 ft of end wall has room for one wide opening or two modest ones, while 100 ft of side wall can carry several without the openings competing. On this plan the deciding factor is whether deep row forage storage or retrieval sequencing should be the first thing reached from the door.

Loader-handled from the open side, with the working face moving as the stack grows and shrinks.

At 25-foot nominal bays the structure works with the layout instead of against it: one row per bay line, walls free of awkward half-positions. Cleaning, maintenance and inspection all need reach, and reach is planned in the gaps rather than in the modules.

Two-plus rows change the access question entirely. Every rear position at 40x100 needs either its own opening or an aisle, and 1 feet of spare width is what that aisle has to come from. A building that cannot be reversed out of is a building that gets used in one direction only.

Extension is cheapest along the 100 ft dimension, where each added bay repeats work already framed; widening past 40 ft is a different frame rather than a longer one. Growing to 40 by 120 adds a 6th run of rows — useful if the constraint is rows rather than the 0 ft already spare at the far end.

Configured as a deep-row store where bales are stacked in long runs back from a single face, 40x100 is judged on whether the 12 rows it holds match the operation, and on whether the 1 feet of spare width leaves the route this mode depends on.

• Does the work need three parked lanes, or two lanes and a moving lane wide enough for equipment to pass, or does it need a second lane that this 40-foot span cannot give?
• Is the 100-foot length being bought for depth, or for the repeated bays — eight to ten repeated bays, which makes the layout a scheduling problem as much as a spatial one?
• What stack height do you plan, and can the loader place a bale above it inside the building?
• Which sides stay open for airflow, and which face the weather?

• 40x40 moves the count from 12 to 6 rows (3 across by 2 deep), which is the reason to choose between them.
• 36x48 moves the count from 12 to 6 rows (3 across by 2 deep), which is the reason to choose between them.
• 30x60 moves the count from 12 to 6 rows (2 across by 3 deep), which is the reason to choose between them.

Because this footprint is planned as a deep-row store where bales are stacked in long runs back from a single face, the useful next reads are different from the ones a differently shaped hay barn suggests: deep row forage storage, retrieval sequencing, row depth planning.