In this tutorial we show you an example of how to make Any of the framing wood. exterior steps 900mm (36″) wide, coming off a A flat floored roofless area adjoining a house. Timber deck: An outside floor structure comprising of posts, bearers, joists and decking boards. 900mm (36″) high.
Practical Safety Rules for Lumber Steps :
1 Treads must be at least 280mm (11 1/2″) deep.
2 Rises must be a maximum of 185mm (7 3/8″) high.
3 Front of tread must overlap the back of tread below by between 15mm (5/8″) to 25mm (1″).
4 There should be no gap more than 100mm (4″) between the Plumb, upright. distance of treads, therefore riser boards will be needed to close any gaps. see Fig1 below
To start off find the overall height from the top to the bottom of the steps.
We know the height of the deck is 900mm (36″) above ground, but the ground coming away from the deck might not necessarily be level and the See fall. of the ground will affect the overall height of the steps.
To find the true overall height of the steps first measure the height of the deck from the ground where the steps are to fit. We know that measurement is 900mm (36″). Then measure out from the deck (in the direction the steps are to go) in a level line, one and a half times the deck height measurement (approximately). In this case, 1350mm. (54″)
See Fig 2
(A) Height of deck off ground. 900mm (36″)
(B) Distance out from deck where steps will finish. This measurement is 1.5x measurement A. 900 (36″)x1.5 = 1350mm (54″)
(C) Level line from top of deck.
(D) This height is the overall height of steps. 900mm (36″) + 150mm (6″) ground slope = 1050mm (42″). Now we know the overall height of our steps which is 1050mm (42″). Next work out the height of each rise. This is the vertical distance from the top of one tread, to the top of the tread above it. We know the maximum height of each rise can be 185mm (7 3/8″) max. Knowing this we need to divide into 1050mm (42″) which is the overall height of the steps, to get an even measurement of 185mm (7 3/8″) or less. In this case, the even measurement is 175mm (7″), as 175 (7″) divides into 1050mm (42″) 6 times. This means that there will be six rises, each 175mm (7″), which gives us a total height of 1050mm. (42″)
We have now established the Any of the three linear measurements, length, breadth and depth. of out steps.
Six Rises at 175mm (7″) and five treads at 280mm (11 1/2″) deep. Always make the treads 280mm (11 1/2″) regardless of the rise measurements.
The Lumber to Use
Stringers – See Dressed./dressed Pressure treated. Refers to lumber that is treated in such a way that the sealer is forced into the pores of the wood. Refers to lumber pressure sprayed with chemicals to lengthen its life expectancy for outside use or inground applications. Pine, 250×50 (2×10) finishes approximately 240×46 (1 1/2x 9 1/2)
Treads – Surfaced/dressed treated Pine, 150×50 (2×6), two per tread. Finishes approximately 145×46 (1 1/2x 5 1/2).
Riser boards – Surfaced/dressed treated Pine, 150×19 (3/4x 5 1/2).
Stringers – 250×50 (2×10), two at 2.1m (7ft)
Treads – 150×50 (2×6), ten at 0.9m (36″)
Riser Boards – 150×19 (3/4x 5 1/2), three at 1.8m (72″)