A healthcare campus is the rare site where the pavement is part of the care pathway. An ambulance apron that ponds delays a patient; a walkway that ices puts a resident on the ground. This page covers the exterior half of that problem — aprons, drop-offs, decks, docks, courtyards and walking loops — and is straight with you about the half we don't sell.
One campus, half a dozen unrelated drainage problems
Walk a hospital or continuing-care campus with a drainage eye and it is really five or six sites wearing one address. An acute building under an enormous low-slope roof. An emergency department apron a heavy truck backs onto several times a day, forever. A porte-cochère where the most fragile people on the property transfer from a car seat to a wheelchair, in whatever weather is happening. A parking structure, a central plant yard of chillers and generators and a bulk oxygen pad, a dietary dock out back. And — increasingly on the same parcel — independent-living cottages, an assisted-living wing, and a memory-care courtyard with a looped path designed to be walked alone by people who fall.
Each zone has its own hydrology, its own governing vehicle, its own consequence for being wrong. What ties them together is that the campus never closes. There is no Sunday to cut a trench across the ambulance bay, no "we'll fix it in the spring" for a puddle at the memory-care door. On a retail site a drainage defect generates a work order; here it generates a diverted ambulance or a resident with a fractured hip.
So we spec differently. Everywhere else our advice is to buy the load class your traffic justifies. Here we tell people to buy past the arithmetic in exactly two places — the ambulance apron and the accessible route — because the campus can't give you the shutdown you'd need to do it twice.
Where our scope stops: this page is the outside of the building
Settle this before you read further. We do not sell interior clinical or food-service drainage, and we make no hygienic or sanitary claims about anything in our catalog. Drainage in surgical suites, sterile processing and decontamination, soiled utility, dialysis and the dietary kitchen is engineered sanitary stainless, specified by the plumbing engineer and coordinated with infection control. Where a hygienic-design or listing requirement applies, it applies to that hardware from those manufacturers. Anyone offering a polymer-concrete site channel for a sterile processing floor is guessing at your expense.
Two more boundaries. We sell no pumps, lift stations, septic or treatment equipment — pumped discharge is a mechanical scope by others. And at the dietary dock, the grease interceptor and any separator downstream of it belong to the plumbing and civil design; a channel collects and conveys, it does not intercept, separate or treat. What we do sell, in depth, is everything from the building line out: the ED apron and EMS turnaround, the porte-cochère, service drives and fire lanes, deck ramps and parking fields, the plant yard, the dock apron, the courtyards and the walking loops.
Reading the water before you read a catalog
Stop thinking about products for twenty minutes and work out where the water concentrates. Three mechanisms do nearly all the damage.
Roof. The bed tower roof is the largest contributor and the least visible. Figure 623 gallons per 1,000 sq ft per inch of rain: a 120,000 sq ft roof yields about 74,760 gallons per inch at a runoff coefficient near 0.95, against 0.20–0.35 for lawn. That volume never spreads out — it arrives through a handful of leaders and hits pavement as a jet. The ice patch in front of a downspout is the whole roof landing in one square foot; see downspout drainage.
Pavement. Aprons, drives and decks shed nearly everything too, as sheet flow following the crown and curb. Where the sheet crosses a threshold — a door, a bay opening, a ramp toe — you get a line of water, and a line wants a line of drain. Where it reaches a dished low spot you get a point, and a point wants a basin. That distinction saves more money than any product choice below.
Groundwater and saturated soil. This one gets mis-diagnosed constantly. A healing garden soggy three days after a storm, a therapy lawn that won't firm up — that is a water-table or permeability problem, and the honest answer is a subsurface system: perforated pipe bedded in washed stone, wrapped in geotextile, running to a legal outlet. On structural-slab courtyards over parking, the equivalent is a planter underdrain above the waterproofing. Both are real parts of a campus's drainage picture, and both are contractor-installed work we don't sell. We sell the surface-collection layer the same courtyard also needs — and we never call a channel drain a french drain, because it isn't one.
Putting a number on it
Peak flow sizes hardware: runoff coefficient × rainfall intensity in in./hr × area in acres = cubic feet per second; × 448.8 = gallons per minute. A 2,400 sq ft porte-cochère canopy (0.055 acre) at C = 0.95 under a 3 in./hr storm is about 0.16 cfs, or 70 gpm — one 4″ outlet. Add a 3,000 sq ft canopy draining onto a 2,400 sq ft ED apron and the same math gives 0.35 cfs, or 158 gpm, already past that outlet. That is the most common capacity mistake we see on healthcare sites.
Hence the rule that governs everything: the outlet is the bottleneck, not the channel. Running full at 1% slope, a 4″ line moves roughly 110 gpm, a 6″ about 330 gpm, an 8″ about 700 gpm. A 12″ channel on a single 4″ outlet is a 110 gpm system in an expensive costume. Work the flow with our Runoff Calculator and the method in Sizing for Storms: Estimating Runoff, then size the outlet, then pick the channel. Hold surface pitch and outlet pipe at 1/8″–1/4″ per foot (1–2%) so the line scours itself; on long flat runs a pre-sloped channel does that for you.
Zone by zone: what belongs where on a medical or senior-living site
Emergency department apron and ambulance bay
The most demanding pavement on the property. A rig backs to the same spot thousands of times a year and drips melt, salt and fluids at the bay opening. Water must never stand where a gurney's 5″–8″ casters roll. Catch the sheet in a line across the bay opening — a continuous channel, not a point basin — and spec Class D 400 kN with a bolted ductile grate. A loose grate rocking under an ambulance tire at 2 a.m. is a call nobody wants.
Porte-cochère and patient drop-off
Light vehicles, heavy consequences. The canopy concentrates roof water at a few columns, the pavement is deliberately flat so wheelchair transfers are safe, and the people crossing it are least able to recover from a stumble. Collect canopy water in a line at the drip edge rather than letting it cross the transfer zone, and pick the grate for the foot and the wheel, not the car.
Parking decks, ramp toes, and the surface field
A deck dumps at the ramp toe, where sheet flow becomes a concentrated stream crossing a pedestrian path. Catch it with a channel spanning the full drive width, grated for the heaviest vehicle on the deck rather than the average one. On the surface field, low-point basins do the work — and a hospital lot fills them with grit and salt faster than you expect, so buy sump depth. Deck side: parking structure drainage.
Central utility plant yard
Chillers, cooling towers, generators, a fuel island and a bulk oxygen pad, on pavement that sees a boom truck at maintenance and a cryogenic tanker at highway gross weight. Nuisance water runs year-round here from tower drift, basin splash and drain-downs, not only during storms. Ring the pads so migrating water never reaches electrical gear — and note that tower blowdown usually may not enter the storm system. Any separator or interceptor is downstream, by others; fuel containment belongs to the civil and fire-protection scope.
Dietary dock, materials management, and the compactor pad
Food-service deliveries, linen, medical-waste trucks, and a compactor that leaks. Heavy-duty pavement with a wash-down habit, so give it a full-width channel with real sediment tolerance and a removable grate. The interior kitchen side of the wall belongs to the plumbing scope. More on dock geometry: loading dock drainage.
Courtyards, healing gardens, and the accessible route
Pedestrian-only, and the toughest grate decision on the campus. Water crosses paved courtyards as thin sheets that pond in the dished spots architects love and freeze there first, because the walls hold shade all day. Collect at door thresholds with a narrow channel, catch low points with basins, and choose every grate against ADA Section 302.3 and the tighter heel-resistant patterns. Keep garden irrigation control serviceable in a proper valve box. Full detail: ADA & pedestrian drainage.
Assisted living, memory care, and independent-living cottages
These read residential and behave like light commercial. Looped paths are meant to be walked unaccompanied, so every square foot is an accessible route in practice whether or not it is one on the drawings. Narrow channels at patio doors, basins at the low corners of the loop, and a discharge that doesn't create a soggy strip where a resident steps off the path — that is where a pop-up emitter or dry well earns its keep. Property-wide: HOA & property management.
Load class when the governing vehicle is an ambulance, not a sedan
EN 1433 supplies the vocabulary, and the class numbers are proof loads on the grate assembly — not wheel loads, and not AASHTO. A 15 is 15 kN (about 3,372 lbf), B 125 is 28,101 lbf, C 250 is 56,202 lbf, D 400 is roughly 90,000 lbf, E 600 is 134,885 lbf, F 900 is 202,328 lbf. The American shorthand — AASHTO H-20 at a 16,000-lb wheel, HS-25 at a 20,000-lb wheel — measures something different under a different regime, so cross-read the two as a heuristic and confirm the published class with the manufacturer and your engineer. Details in our Load Class Recommendation Guide.
Campus zone → class we spec → the vehicle driving it
Zone
Class we spec
Governing vehicle
ED apron & ambulance bay
D 400 minimum
Type I / III ambulance, 14,000–19,500 lb GVWR; usually a fire lane too
Fire lane & EMS turnaround
D 400
Apparatus — the common access-road provision asks for at least 75,000 lb
Plant yard & fuel island
D 400; E 600 at the tanker stand
Cryogenic and fuel tankers at highway gross; boom truck
Dietary dock & compactor pad
D 400
Loaded food-service and waste trucks; roll-off hooklift
Deck ramp toe & service drives
C 250–D 400
Shuttle buses, box trucks, patient-transport vans
Porte-cochère drive lane
C 250
Cars, wheelchair vans, the occasional shuttle
Staff & visitor parking field
B 125–C 250
Passenger vehicles; C where a plow or delivery truck cuts through
Courtyards, walks, memory-care loops
A 15–B 125, heel-resistant
Foot traffic, walkers, wheelchairs; B 125 where maintenance carts run
Two cautions. Class ratings assume full concrete encasement per the manufacturer's instructions — a Class D channel in a thin slab is a Class D invoice with a Class B result. And securement is part of the rating: in public healthcare space a grate that lifts by hand is a liability whatever it carries.
What we'd spec, campus location by campus location
The picks we actually make when someone sends us a healthcare site plan. Every capacity figure assumes you sized the outlet first.
For the ED apron, EMS turnaround and fire lane. Engineered bodies and ductile grate options reach the classes an ambulance apron deserves, and grate securement is designed rather than improvised. The S100K covers a 40 ft bay opening on one run; step to the S200K where the apron also takes canopy roof water and your flow calc passes roughly 250 gpm.
Why here: the ED apron is the one place on campus you cannot take offline to redo, so buying the engineered line once is cheaper than the phasing plan to replace a lighter one. Send run length, load class, grate material and outlet locations to request a quote — we respond within one business day.
Dura-Slope carries a built-in slope — what a flat service drive or long turnaround needs when the pavement won't give you pitch. With the ductile iron channel grate and matching frame it becomes the heavy-traffic tier of a system you can buy today, which matters on a phased job where a two-week lead time is a schedule problem.
Where it isn't the answer: if the run is in the ambulance path or a fire lane, spec the engineered line above and confirm ratings against the load guide. Dura-Slope's sweet spot is everything adjacent — the drive that reaches the apron, the loop road, the back-of-house route.
Best grate for walkers, canes, and wheelchair casters
ADA/heel-proof ductile iron grates — and Josam Pro-Plus 100 slotted · on request
The decision that matters most on a senior living route, and the one most often made by default. ADA 302.3 caps openings at a 1/2″ sphere, elongated openings perpendicular to travel — legal, and still a half-inch gap where people arrive on wheels and rubber tips. The tighter tier is real product: the Filcoten 100 ductile bar grate is published ADA/heel-proof at Class C, the Filcoten 200 ductile Kiaro reaches Class D, and Josam's Pro-Plus 100 ductile slotted grate carries ADA/heel-proof in the model name at Class C and Class F — available to us on request, so ask for it.
Why it earns the premium: a 1/2″ slot running the wrong direction will steer a 1″-wide caster and stall a rollator's front wheel. Then hold the joint — Section 303 allows 1/4″ as-is, 1/4″–1/2″ beveled no steeper than 1:2 — so set the grate 1/8″–1/4″ below finished pavement and let the encasement take the wheel load. Background: our ADA drainage design guide.
Porte-cochères and entry plazas where the architect wants no grate in the photograph. ACO's heel-resistant Brickslot units present offset double 5/16″ (8 mm) openings instead of one continuous half-inch gap, seat into the K100 recess, and take access units in the run. Ask about the KS100 stainless-edge version where salt and de-icer are part of the winter routine.
Why we insist on the access units: a tight slot collects debris faster than a wide one — physics, not a defect. Buy the tighter opening for the people and the maintenance access to go with it, or the line is decorative by year two. Quoted by run length and paver or slab thickness.
Best run for the dock, compactor pad, and plant yard
Back-of-house pavement wants cross-section and sediment tolerance more than finesse. The K200 and K300 give you depth for a full-width dock apron and the grate catalog to match truck traffic. Prefer a fiber-reinforced high-performance concrete body? Filcoten's 8″ Tec V200 and 12″ Tec V300 cover the same ground, with ductile grates published to Class E in the 300 series — patterns in Filcoten channel grates.
The trade-off: KlassikDrain wins on grate breadth and accessories, Filcoten on body material and availability. Either beats what we actually get called about — a 12″ channel hung on a 4″ outlet.
Best cart-able ladder from cottage patio to deck ramp
One family covers most of the campus you can buy off the shelf. At a ramp toe or drive threshold the 8″ and 12″ Pro Series carry serious cross-section with a grate ladder from pedestrian HDPE through galvanized steel to cast iron and ductile iron; the 5″ and 3″ handle door thresholds. Cottage patios and garden walks drop to Spee-D, Mini or Micro — see channel grates and the by-width view when matching an existing opening.
Modular sections hit odd widths without fabrication, and swapping or upgrading a grate later without touching the channel body is worth real money on an occupied campus. The mistake we see is a Mini Channel run across a maintenance-cart route — where a wheel crosses, step up to Pro Series and a metal grate.
Best low-point collection in a courtyard or walking loop
Where water collects at a point rather than crossing a line, a basin is the right tool and a channel is an expensive wrong one. The 12″ suits a small courtyard or cottage low corner; the 18″ and 24″ take a plaza or parking field with a sump deep enough to trap the grit a hospital lot produces. Basin kits bundle the outlets; universal outlets and drainage fittings get you to pipe.
Two opinions worth having. Use an atrium grate in planted areas where mulch would blind a flat one — but on any surface a resident walks, use a flat grate meeting the opening rule: an atrium grate in a walking loop is a trip hazard with a drainage function. And put the discharge past the loop, not beside it, or you've built the soggy step-off strip you were trying to prevent.
Questions we get from facilities directors, architects, and site contractors
What load class does an emergency department ambulance apron need?
Class D 400 kN at the bay, held to the apron edge. A Type I or Type III ambulance runs 14,000 to 19,500 lb GVWR, arrives loaded, and brakes on the same square yard of pavement several times a day — and that apron is almost always a designated fire lane, where the widely adopted access-road provision asks for pavement able to carry apparatus of at least 75,000 lb. EN 1433 class values are proof loads on the grate assembly, about 56,200 lbf at C 250 and 90,000 lbf at D 400, not wheel loads; AASHTO H-20 at a 16,000-lb wheel and HS-25 at 20,000 lb measure something different. Cross-read them as a trade heuristic, never a standards equivalence.
Do you sell floor drains for sterile processing, the dietary kitchen, or clinical spaces?
No. Interior drainage in surgical suites, sterile processing, decontamination, soiled utility, dialysis and the dietary kitchen is engineered sanitary stainless work, fabricated to the plumbing engineer's submittal and coordinated with infection control. We do not stock it, we do not fabricate it, and we make no hygienic claims about anything in our catalog. Everything on this page is exterior: ambulance aprons, drop-off canopies, parking decks, plant yards, dietary docks, courtyards and walkways.
What grate opening is safe for walkers, canes, and wheelchair casters?
ADA Section 302.3 is the floor: openings must not pass a sphere larger than 1/2 inch, and elongated openings run with the long dimension perpendicular to the dominant direction of travel. Section 303 allows a vertical change of 1/4 inch as-is and requires 1/4 to 1/2 inch to be beveled no steeper than 1:2, which governs the grate-to-frame joint and the basin lid. Then go tighter: a 1/2 inch slot running the wrong way will steer a 1-inch-wide caster and stall a rollator wheel. Heel-proof and heel-resistant ductile and steel patterns present roughly 5/16 inch openings, and that is what we put on a senior living route.
How much water comes off a hospital roof and its entrance canopy?
About 623 gallons per 1,000 square feet per inch of rain, at a runoff coefficient near 0.95 against 0.20 to 0.35 for lawn. A 120,000 square foot bed tower roof yields roughly 74,760 gallons per inch. A 2,400 square foot porte-cochère canopy yields about 1,495 gallons — small in total, but delivered through two to four column leaders onto the one strip of pavement where patients transfer out of a car. Concentration, not volume, is what fails at a drop-off.
How do I know a campus drain run has enough capacity?
Check the outlet, not the channel. Running full at a 1 percent slope, a 4-inch line carries roughly 110 gallons per minute, a 6-inch line about 330, an 8-inch line about 700. A 3,000 square foot canopy draining onto a 2,400 square foot apron under a 3 in./hr storm is about 0.35 cubic feet per second, near 158 gallons per minute — already past one 4-inch outlet. Work out peak flow with our runoff calculator first, size the outlet second, and pick the channel third.
Our healing garden has a wet corner. Is a french drain the answer, and do you sell one?
Often yes to the first, no to the second. A courtyard or therapy garden soggy for days is usually a water-table or permeability problem, solved by a contractor-installed french drain: perforated pipe bedded in washed stone, wrapped in geotextile, running to a legal outlet. We do not sell perforated pipe, stone or geotextile, and nothing in our catalog is a french drain. We sell the surface layer the same courtyard also needs — the basin at the low point, the channel at the door threshold, the fittings to the contractor's pipe, and the pop-up emitter or dry well at the discharge.
Specifying drainage for a hospital or senior-living campus?
Send the zones, governing vehicles, run lengths and your phasing — we'll spec the load class and grate pattern for each and quote it within one business day. ACO KlassikDrain and PowerDrain are quote-only; Josam Pro-Plus is available on request.
