You can assess this in two ways either as the roof pitch angles which the rafters make with the horizontal or the proportion between the run and the rise of the roof.
How to work out the gauge on a slate roof.
Total linear run of tile batten in metres.
Often you express roof pitch as the ratio between the rise and the run in the form of x 12.
This calculator will estimate the following number of slates required per square metre.
Please enter the dimensions in the white fields below and click calculate to show the results.
The supplier of the slates should recommend the spacing up the roof between the battens known as the gauge this usually varies according to the size of the slates the pitch of the roof and the degree of exposure.
Just short of the centre of the gutter.
Holing gauge batten gauge headlap 10mm.
The result is the number of courses of tile on the roof rounded to a whole number.
Height of slate minus desired headlap divided by two gauge i e.
For example if the distance between the tops of the lower and upper battens is 204 inches and the maximum gauge of the tiles is 13 inches then the number of courses and strips of batten is 16 because 204 13 15 6.
The holing gauge can be calculated as.
Batten gauge length of slate headlap 2.
Roof pitch refers to the slope which the rafter creates.
The next thing to do is to work out the spacing for the battens up the roof.
The gauge quoted by the supplier.
The batten gauge can also be calculated using the formula.
The slate or tile manufacturer or supplier will specify the spacing of the battens up the roof for the particular type of covering this spacing is referred to as the gauge the gauge may depend upon the pitch of the roof and the amount of exposure.
Our slate calculator will do the rest remember when checking out to add 10 more onto the total in order to cover wastage.
It also allows you to determine the holing gauge distance from hole to tail of slate and the number of linear metres of batten per m 2 of roof.
For a 500mm long slate with a 100mm headlap the gauge is 500 100 400 2 200 so we know the gauge is 200mm.
X the nail hole clearance so that a nail does not strike the top of the slate underneath.
Tile batten gauge for slate.
Slate half slates at the verge outer edge of the roof it is general practice to alternate courses of standard size slates and the slate and half s which are 1 5 the width of normal slates.
Setting out up the roof gauge set the first batten at eaves to allow the tails of the eaves course tiles to overhang the fascia by 40 to 45mm ie.
Set the last batten at the ridge so that the ridge tiles will overlap the top course of tiles by at least 75mm.
