On a Fabric Building, the End Wall Is the Door
Buyers come to this question carrying a steel-building habit: pick an overhead door off a size chart, frame the opening, bolt it into one wall. A peaked fabric building does not work that way, and the difference changes the whole sizing exercise. The MAX standard configuration puts a full-width winch roll-up door across the entire gable end — front and back — plus two zipper man doors for walk-through access. You are not choosing a 12-ft or 14-ft door. You are opening the whole end of the building.
That means the clear opening is not set by a door product. It is set by the building's own profile: the width of the span and the height of the arch. A 40-ft-wide building gives you a 40-ft-wide end to drive through; a 70-ft-wide building gives you 70. The practical limit is height, and height is governed by the peak. So the honest version of "what size door do I need" is "what width and peak height clear my tallest machine on the way in." Get those two numbers right and the door takes care of itself.
Step One: Measure the Machine, Not the Doorway
Start with the equipment, at its transport dimensions — folded, lowered, header removed, whatever you actually do to move it down the road. Transport height and transport width are the numbers that matter, and they are usually smaller than working dimensions but larger than people guess. Here is what common equipment actually measures, drawn from manufacturer spec sheets, with the opening height we would spec for each.
| Equipment | Transport height | Transport width | Recommended clear opening height |
|---|---|---|---|
| Pickup with topper / utility trailer | ~7 ft | ~7–8.5 ft | 9 ft |
| Compact / utility tractor with cab | ~8–9 ft | ~6–7 ft | 11 ft |
| Row-crop tractor, cab, loader lowered | ~11–12 ft | ~8–10 ft | 13 ft |
| Self-propelled sprayer, folded | ~12 ft 6 in | ~12 ft | 14 ft |
| Class A motorhome / fifth-wheel RV | up to 13 ft 6 in | ~8.5 ft | 15 ft |
| Tandem grain truck, box down | ~12–13 ft | ~8.5 ft | 15 ft |
| Air drill / air seeder, folded | ~13–15 ft | ~16–18 ft | 17 ft |
| Large combine, header off (e.g. JD S680) | ~16 ft 6 in | ~17 ft 8 in | 18 ft |
Two rules sit underneath that table. First, add at least 1 ft of headroom over the tallest point and 2 ft of clearance per side — nobody threads a machine through an opening with zero margin, in the dark, in a hurry, at harvest. Second, machinery grows. The combine you buy in five years will likely be taller and wider than today's, so spec to the machine you expect to own in ten years, not the one in the yard now. A foot of extra peak costs far less than a building that fits everything except your next purchase.
The Peaked-Roof Clearance Trap
Here is the part that catches people, and the single most useful thing in this article. Peak height is a centreline number. The arch is highest in the middle and sweeps down toward each sidewall, so the clearance you actually have depends on where across the width your machine passes through. Quote a building by its 23-ft peak and a buyer pictures 23 feet of headroom across the whole opening. They do not have it. Drive 8 feet off-centre on that same building and the arch has already dropped several feet.
This is why a tall, narrow machine wants to go down the middle, and why a wide machine needs more total width than its own width suggests — it has to fit inside the part of the arch that is still high enough. A combine that is 17 ft 8 in wide and 16 ft 6 in tall does not simply fit a building wider than 17 ft 8 in; it needs a span where the roof is still near 17 ft of clearance across that whole 17-plus feet of machine. On a 40-ft-wide building (23-ft peak) a combine clears on the centreline but runs out of height toward the sides; on a 60-ft-wide building (25-ft peak) the high part of the arch is wide enough to take it comfortably. The taper is the reason combine owners step up a width class.
MAX Peak Heights by Width
Because the building width sets both the opening width and (through the arch) the peak height, the MAX line maps cleanly onto equipment classes. These are published dimensions, not estimates.
| Building width | Peak height | Clears on the centreline | Representative use |
|---|---|---|---|
| 20 ft | 16 ft | Pickups, side-by-sides, small trailers | Yard storage, workshop bay |
| 30 ft | 20 ft | RVs, grain trucks, compact tractors | RV/boat storage, small fleet |
| 40 ft | 23 ft | Row-crop tractors, sprayers, most farm gear | General farm equipment |
| 50 ft | 23 ft | Side-by-side equipment rows, sprayers | Mixed fleet, hay and machinery |
| 60 ft | 25 ft | Combines, folded air drills | Large-acre grain operation |
| 70 ft | 28 ft | Fully extended combines, multiple rows | Commercial / large fleet yard |
| 80 ft (Industrial) | 900g cover, custom spec | Widest equipment, drill masts, lifts | Industrial / clear-span |
A reliable shortcut: match the building width to your widest machine plus working room, then confirm the peak clears the tallest. For most mixed farm fleets that lands on a 40-ft width (23-ft peak), which clears everything short of a fully raised drill mast. Combine-first operations should start at 60 ft (25-ft peak). RV and grain-truck owners rarely need more than 30 ft (20-ft peak), since a road-legal load is capped at 13 ft 8 in to begin with. The width also sets your usable floor, and on a clear-span fabric building there are no interior posts eating into it.
Drive-Through or Single-End? Matching the Door Layout to Workflow
Because both gable ends roll up as standard, a MAX building is a drive-through by default, and that is worth more than it sounds. If you load from one end and unload from the other — feeding equipment in at harvest, pulling it out the far side, running a wash bay, staging a fleet — the front-and-back opening saves a three-point turn inside the building on every single pass. Over a season that is hours of fiddling and a lot less risk of clipping a sidewall with a header.
If your site only allows access from one side, the second end still earns its place: open it for cross-ventilation on a hot day, light, or summer airflow over stored hay, then zip it shut for winter. The two included zipper man doors handle the daily walk-in traffic so the big doors stay down except when a machine is actually moving. Door layout, in other words, is a workflow decision more than a hardware one — the hardware is already there on both ends.
For more on how the ends of the building are configured, see choosing the right end-wall configuration, and for sizing the building as a whole, how to choose the right building width.
Match Your Equipment to a Building: A Decision Tool
Place your tallest, widest machine in one of these bands before you talk price:
- Tallest item is a pickup, side-by-side, or small trailer (under ~10 ft): a 20- or 30-ft-wide building (16–20 ft peak) is plenty. Do not buy peak you will never drive into.
- RV, fifth-wheel, or grain truck (road-legal, under 13 ft 8 in): 30-ft width, 20-ft peak. The legal road-height cap means you cannot own something that needs more.
- Row-crop tractors, self-propelled sprayer, general farm fleet: the 40-ft width (23-ft peak) is the workhorse — centreline height for a folded sprayer at ~12 ft 6 in with comfortable margin, and room to back equipment in side by side.
- Combines, folded air drills, anything 16–18 ft tall or wide: step up to 60- or 70-ft width (25–28 ft peak) so the high part of the arch is wide enough to take the machine, not just the centreline.
- Need full height across a wide path, drill masts, or 80-ft clear span: the tall-wall straight-sidewall flagship or the 900g MAX Industrial Series.
Five Questions to Ask Before You Order
Answered honestly, these five separate a building that fits your equipment from one that fits it on paper:
1. What is the transport height and width of my tallest and widest machine — folded, header off, lowered? (If you do not have these in writing, measure before you spec; guessing here is the expensive mistake.)
2. What is the peak height of the building, and at what width does the arch drop below my machine's height? (The peak is a centreline number; ask where the usable clearance ends.)
3. Are front and back roll-up doors and man doors included, or priced separately? (On a MAX building both ends and two zipper man doors are standard — confirm any quote you compare includes the same.)
4. Do I load and unload from the same end or opposite ends? (If opposite, the drive-through layout saves a turn inside on every pass — spec it deliberately.)
5. What will I own in ten years? (Spec the building to the machine you will buy next, with a foot of headroom to spare, not the one parked there today.)
Get the answers in writing. Get a quote and tell us your tallest machine and how you move it — the building we recommend is, quite literally, the door you will drive through for the next two decades.
Related Resources
Frequently Asked Questions
What size door do I need to fit a combine?
A large combine such as a John Deere S680 stands about 16 ft 6 in tall and 17 ft 8 in wide in transport with the header removed, so the opening has to clear roughly 18 ft of height and 20 ft of usable width at door level. On a peaked fabric building that points you to a 60-ft-wide model (25 ft peak) or wider, where the arch holds combine height across enough of the centre to drive straight in. A 40-ft-wide building (23 ft peak) clears a combine on the centreline but leaves little side room.
How tall should a farm equipment shed door be?
Industry and extension guidance puts most farm equipment under a 13 to 15 ft door, with 18 to 20 ft needed for the largest combines and folded air drills. Add at least 1 ft of headroom over your tallest machine's transport height. On a MAX building the door is the full gable end, so the controlling number is the peak height: 20 ft on a 30-ft-wide building, 23 ft on a 40 or 50, 25 ft on a 60, 28 ft on a 70.
Does a fabric building have a normal overhead garage door?
Not the way a steel building does. The MAX standard is a full-width winch roll-up door at the front and back of the gable ends, plus two zipper man doors for walk-through access. Instead of a fixed framed opening sized off a catalogue, the whole end wall lifts, giving drive-through clearance limited only by the building's own arch profile. A framed personnel or smaller door can be added, but the standard layout is built around opening the entire end.
Can I drive a semi or grain truck through a fabric building?
Yes, within the legal height limit. Canada caps road vehicle height at 4.15 m (13 ft 8 in) before an over-height permit is required, so any truck that legally reached your yard fits under a 20 ft peak with room to spare. A 30-ft-wide MAX building (20 ft peak) clears a tandem grain truck driving in with the box down; never hoist a box inside the building.
What is the widest door MAX offers?
Because the door is the end wall, the widest opening equals the building width. The standard line runs to 70 ft wide, and the 80-ft-wide MAX Industrial Series opens an 80 ft span. The tall-wall 70x200x32 flagship adds 16 ft straight sidewalls and a 32 ft peak with a 20x20 drive-through door for the largest equipment. Usable door width is always less than full span because the arch curves down toward the sides.
Do I lose height near the sidewalls because of the curved roof?
Yes, and it is the most common sizing mistake. The peak height applies only down the centreline. On a 40-ft-wide building with a 23 ft peak, the clearance several feet off-centre is already several feet lower as the arch sweeps down to the sidewall. Drive tall equipment down the middle, and if you need full height across a wide path, step up to a wider building or the tall-wall straight-sidewall flagship.
Will a motorhome or fifth-wheel RV fit in a fabric building?
Almost always. A Class A motorhome or fifth-wheel tops out around 13 ft 6 in, under Canada's 13 ft 8 in legal road height. A 30-ft-wide MAX building (20 ft peak) clears any road-legal RV with margin, and a 40-ft-wide model lets you park two side by side. Measure roof-mounted air conditioners and antennas, which add height the brochure figure may not include.
Are the man doors included or an extra cost?
Two zipper man doors are included as standard on MAX buildings, alongside the front and back winch roll-up doors. That walk-through access means you are not opening the full end wall every time someone needs to step inside. Framed steel personnel doors can be specified where a sealed, lockable entry is required.
What size building do I need for a self-propelled sprayer?
A self-propelled sprayer folds to roughly 12 ft 6 in tall and about 12 ft wide in transport, so a 30-ft-wide building (20 ft peak) clears it on the centreline and a 40-ft-wide model (23 ft peak) gives comfortable side room to swing the boom rests in. Confirm your specific model's folded transport height, since high-clearance sprayers run taller.
Can the door size be changed after the building is up?
The roll-up door covers the full end, so the opening size is fixed by the building width and peak you order at the start, not adjusted afterward. That is why the door question is really a building-size question. Spec for the largest machine you expect to own over the next 10 years, because equipment tends to grow a foot or two per generation, rather than for what is in the yard today.
Not sure which width clears your equipment?
Tell us your tallest machine and how you move it, and we will spec the width and peak that clears it with room to spare. Full-width roll-up doors both ends, standard. 750g cover. Double-Trussed Standard frame. From $5,888 for the building.
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