Short answer: platform height is how high the deck you stand on sits above the ground. Working height is how high you can reach from it, about 6 ft more. To pick a scaffold, measure the highest point you need to reach from the ground where the tower will stand, subtract about 6 ft, and rent equipment whose deck goes at least that high. Above about 18 ft of working height, or along a long wall, frame scaffold is the usual answer.
General information only, not legal or engineering advice. Rules change: check the linked primary sources or ask Cal/OSHA before you rely on them.
Working height vs platform height
Platform height is a measurement of the deck. Working height is an estimate of how high an average adult can reach while standing on that deck. Equipment is often sold or rented by working height, so the number in the name is not the height you stand at.
MetalTech's numbers for its Jobsite Series 6 ft Baker unit show the gap. One unit has a deck adjustable from 27 to 73 in, and the manufacturer rates it for a 12 ft reach. That is about 6 ft above the highest deck setting. MetalTech rates three stacked units for a 24 ft reach.
Use about 6 ft as a planning number, not a promise. Shorter people reach less, and work over your head is slower and harder to control. Work is usually easier to control when it sits between your chest and shoulders.
How to measure the height you need
Measure from the ground where the tower will actually stand to the highest point you have to touch. Do not estimate from the number of stories, because two houses with the same number of floors can differ by several feet.
- Pick the highest spot of the job: the top of the gutter, the peak of the gable trim, the top window header.
- Measure it from the ground below it. A laser distance meter is the easiest way. You can also lower a tape from a window and add the window height, or count siding rows and multiply by the visible width of one row.
- Measure from the surface the tower will stand on. A raised foundation, a step down to a patio or a driveway that falls away from the house all change the number.
- Subtract about 6 ft. That is the deck height you need.
- Check the ground. A rolling tower needs a firm, flat and level surface. Grass, gravel and slopes rule it out, whatever the height.
Which Kireon scaffold fits which height?
Match the highest point you measured to the equipment below. Kireon lists its towers by working height, so compare your number with the listed figure first.
| Highest point you need to reach | What to ask for | Why |
|---|---|---|
| Up to 15 ft | 15 ft rolling tower | Listed at 15 ft working height, mason-style steel frames on a 5 ft x 7 ft base |
| Up to 18 ft | 18 ft rolling tower | Listed at 18 ft working height, Baker-style units with an adjustable platform |
| Above 18 ft, or a long wall | Frame scaffold by quote | Frames stack higher and run along the wall |
| Above 36 ft of scaffold | A scaffold contractor | Cal/OSHA requires a permit for employer jobs at that height |
The 18 ft tower is a MetalTech Baker-style stack, and the manufacturer's 24 ft reach rating for three units is higher than Kireon's listed 18 ft. Plan around the listed figure and ask Kireon for the deck height of the configuration you rent. The 18 ft tower specs guide covers frame size, load ratings and outriggers.
What height scaffold do you need for a 2 story house?
On a two-story house, the answer depends on which part you work on: second-floor windows, the eave or a gable peak. Measure each one on your own house, because ceiling height, floor framing and the foundation all change it.
- Second-floor windows: measure to the top of the window trim. If that is 18 ft or less, one of the rolling towers can usually reach it from a level driveway or patio.
- Second-floor eaves and gutters: measure to the top of the gutter. If it is above 18 ft, plan on frame scaffold.
- Gable ends: the peak of a gable sits well above the eave. A tower that reaches the gutter usually falls short at the peak, so measure the peak separately.
On a one-story ranch house, if the gutter measures 15 ft or less, the 15 ft tower covers it. On a two-story tract home, the windows may be tower work while the full wall up to the eave is frame scaffold work. Older houses with tall gables, high ceilings or a raised foundation need the tape measure most.
What size scaffold do you need for a 20 ft wall?
A 20 ft wall is past the listed working height of both rolling towers, so plan on frame scaffold. Frame scaffold also lets you walk along the wall instead of rolling a tower and climbing down every few feet.
Height brings rules with it. Cal/OSHA Title 8, Section 1644 requires metal scaffold to be tied to the building at the free ends once the platform height exceeds 3 times the least base dimension. Section 1646 sets the same idea for rolling towers: the base must be at least 1/3 of the height unless the scaffold is guyed or tied. That is why a stacked Baker tower needs its outriggers. Both sections require railings on any platform 7 1/2 ft or more above grade.
If you are unsure between a tower and frame scaffold, read rolling scaffold tower vs frame scaffold.
Can you rent scaffold for a three-story house?
Not a rolling tower. Three stories are beyond the 18 ft tower, and a scaffold planned to be more than 36 ft high when complete needs a Cal/OSHA permit under Title 8, Section 341 when an employer erects it. The Cal/OSHA scaffold rules guide explains when those rules apply to a homeowner job.
For a tall wall, send the measured height, wall length and ground conditions with a quote request. Kireon confirms in a written quote what it can rent for the job, or tells you the job is outside what it rents.
Mistakes that cost height
- Counting stories instead of measuring. Ceiling heights and foundations vary from house to house.
- Measuring from the porch, not the ground. The tower stands on the ground, so measure from there.
- Forgetting the gable. The peak is higher than the eave.
- Adding height on the deck. Never put a ladder, bucket or anything else on the platform to reach higher. If the tower is short, you need a taller setup.
- Overreaching. MetalTech's manual says to keep your body centered inside the scaffold. Move the tower instead of leaning out.
Kireon rents and sells equipment only and does not set up scaffolding. You or your crew assemble the tower or frame scaffold following the manufacturer's instructions.
Frequently asked questions
What is the difference between working height and platform height?
Platform height is how high the deck sits above the ground. Working height is how high a person standing on the deck can reach, about 6 ft more. MetalTech rates a single 6 ft Baker unit with a 73 in maximum deck for a 12 ft reach.
How high can I reach on an 18 ft rolling scaffold?
Kireon lists its 18 ft rolling tower at 18 ft working height. MetalTech rates three stacked 6 ft Baker units for a 24 ft reach. Plan around the listed 18 ft and ask Kireon for the deck height of the configuration you rent.
What height scaffold do I need for a 2 story house?
Measure from the ground to the highest point you will work, then subtract about 6 ft for the deck height. If that point is 18 ft or less, a rolling tower can fit on level ground. Eaves and gable peaks above 18 ft need frame scaffold.
What size scaffold do I need for a 20 ft wall?
A 20 ft wall is above the listed working height of Kireon's 18 ft and 15 ft towers, so plan on frame scaffold, priced by quote. Under Cal/OSHA Section 1644, taller metal scaffold must be tied to the building.
When does a scaffold need to be tied to the building?
Under Cal/OSHA Title 8, a rolling tower's base must be at least 1/3 of its height unless it is guyed or tied (Section 1646). Metal frame scaffold needs ties at the free ends once platform height exceeds 3 times the least base dimension (Section 1644).
Can I put a ladder on a scaffold platform to reach higher?
No. Never put a ladder, bucket or box on a scaffold platform to gain height. If the tower is too short for the job, rent taller equipment or switch to frame scaffold.
Sources
- MetalTech: Jobsite Series 6 ft Baker (I-CISC) product page
- MetalTech Jobsite Series 6 ft Baker (I-CISC): Operational Safety and Assembly Instructions (PDF)
- Cal/OSHA Title 8, Section 1646: Tower Scaffolds and Rolling Scaffolds, Wood or Metal
- Cal/OSHA Title 8, Section 1644: Metal Scaffolds
- Cal/OSHA Title 8, Section 341: Permit Requirements
Next step: see rolling tower rental or frame scaffold rental, then request a quote with your dates and ZIP code.
Kireon provides scaffold equipment rental and sales only. Kireon does not erect, assemble, dismantle, engineer, design, inspect or supervise scaffolding and does not provide competent-person or jobsite safety-management services.