Calculate first-batten position, geometric gauge, uniform batten setout or field tile quantity. Use product-specific headlap/gauge limits and consistent site measurements; generic pitch-based headlap recommendations are not supplied.

Geometry estimate. Use the tile manufacturer’s headlap, gauge limits and setting-out details for the actual pitch/exposure. All setout offsets must share the same along-slope datum; no generic headlap recommendation is supplied.

Related Calculators

Roof Tile Spacing Formula

The following geometry locates the top edge of the first tile batten from a fascia datum along the roof slope. It does not calculate first-to-second batten spacing; check the actual tile and eaves detail.

RTS = LT - LGO - LN

Variables:

  • RTS is the first-batten top-edge offset from the fascia datum along the roof slope (inches)
  • LT is the length of the tile (in) 
  • LGO is tile-tail overhang from the fascia datum, measured along the slope (in) 
  • LN is the head-to-nib bearing-face offset measured along the tile (in) 

How to Calculate Roof Tile Spacing?

For uniform setout, measure between the top edges of the first and last full-tile battens. Intervals = ceiling(span ÷ maximum product gauge); uniform gauge = span ÷ intervals. There are intervals + 1 endpoint batten lines, excluding additional eaves/top battens. A rafter-length input requires true end offsets, not first-to-second spacing or ridge-tile overlap. See Marley’s setting-out guidance and the actual product instructions.

Use consistent along-slope measurements. Single-lap gauge is tile length minus required headlap; double-lap gauge is half that difference. Manufacturer exposed course height is already gauge and must not have headlap subtracted again.

  1. First, determine the length of the tile (in).
  2. Next, determine the length of the gutter overhang (in). 
  3. Next, determine the length of the nib (in). 
  4. Next, gather the formula from above = RTS = LT - LGO - LN.
  5. Finally, calculate the first-batten offset and verify the actual eaves position.
  6. After inserting the variables and calculating the result, check your answer with the calculator above. 

Example Problem:

Use the following variables as an example problem to test your knowledge.

length of the tile (in) = 3.5

length of the gutter overhang (in) = 1

length of the nib (in) = .30

RTS = LT − LGO − LN = 3.5 − 1 − 0.30 = 2.20 in (hypothetical geometry only).