Fire extinguisher travel distance and coverage for Houston buildings
Travel distance is the route a person walks to reach an extinguisher, around every partition, rack and closed suite door in the way. NFPA 10 caps that walk at 75 ft for Class A hazards and 50 ft for Class B. One unit relocated during a fit-out puts a whole suite past the limit.
Travel distance fails quietly
An expired tag is visible from across the room. A unit now 96 ft from the far corner of a suite looks exactly like a unit that is compliant. Three things cause it.
- 01
The plan lies about the walk
A straight line on a floor plan crosses walls. A person does not. Travel distance is measured along the route someone actually walks, around every partition, rack and closed suite door, which is routinely half again what the drawing suggests.
- 02
One relocated unit moves the whole limit
A fit-out takes a unit off a column and nobody remounts it. The building looks unchanged and the suite behind that column is now past 75 ft. This is a paperwork-grade failure with no visible symptom until an inspector walks it.
- 03
Racking and fixed plant redraw the route
A rack run added after the last inspection turns a 40 ft walk into a 120 ft one. The unit count on your service record stays the same, so nothing in the file tells you the coverage changed.
Plan the coverage on a floorplate
Pick a plate, drag the units, and read the square footage that sits past the limit. The walk is computed the way a person takes it, so a wall between a unit and a room counts against you.
Three suites off a corridor, a break room, a records room and a warehouse bay at the back. 24,000 sq ft, drawn with four units and three of them stranded in the office half.
The floorplate drawing needs JavaScript. The travel limits are 75 ft for Class A hazards and 50 ft for Class B.
CLASS A · 75 FT TRAVEL
North
Drag a unit. Or tab to one and use the arrow keys.
Coverage readout
Place the units and the uncovered floor is measured as you go.
- Coverage
- –
- Uncovered
- –
- Gap areas
- –
- Worst walk
- –
- Units
- –
- Within reach
- Beyond reach, hatched
- Extinguisher
Mounting height, signage and the annual tag are set on site by a registered technician. Texas firm registration number 3520480.
The three plates are representative examples drawn for this page, not Hamilton jobs, and no building shown here belongs to a customer. Travel distance runs on a 2 ft grid with an eight direction shortest path that walks around walls and racking and never cuts a corner, which approximates the route a person walks rather than a straight line across the plan. On a device where the recompute keeps running long the grid coarsens to 3 ft cells, and the figures move when it does: a coarser cell resolves less of the floor, so the coverage percentage can fall several points and the worst walk can lengthen. The cell size above says which grid produced the numbers you are reading. The 75 ft and 50 ft figures come from NFPA 10, which sets Class B between 30 and 50 ft by hazard level, and cooking appliances at 30 ft. Check the figure against the edition your authority having jurisdiction enforces. This is planning guidance, not a compliance certificate.
What to do with the number
The plate tells you where to look. Confirming it takes a walk with a tape and a camera, and it is work your own staff can do before you call anyone.
- 01
Walk the route, not the plan
Start at the furthest corner of each space and pace the path to the nearest unit. Count the steps around the obstruction rather than through it.
- 02
Photograph every mounting position
A dated photo of each bracket is what tells you a unit moved during a fit-out. It costs ten minutes once and settles an argument later.
- 03
Send us the count and the layout
We read the tags, check placement against the hazard class on site, and put the findings in writing with the service record.
The mounting heights, the intervals and what a fire marshal reads first are all in thecompliance guide.
Send the layout and we will check placement on site
Give us the site address and a unit count. We read every tag, check travel distance against the hazard class in each space, and put the findings in writing.