Calculate angled cut ?

[sardine]

I have some sheets of ply ( shed sides ) measuring 1035mm wide I need to cut a 15 deg roof angle on but I haven't got any angle measuring device , what would be the measurement in mm ?

 

[eLuSiVeMiTe]

https://www.blocklayer.com/riserun.aspx

Should do what you need.

 

[Seadog]

I make it 277mm down.

 

[eLuSiVeMiTe]

I make it 277mm down.

Yes.

 

[bigegg]

i would do it with a pair of dividers.
mark an equilateral triangle in the corner, then bisect twice.

 

[eLuSiVeMiTe]

i would do it with a pair of dividers.
mark an equilateral triangle in the corner, then bisect twice.

In the real world (edit on the job and flat out) I've either pull out my construction master and work out the run/rise or more likely I'd measure the length of my board from the point and mark. Run a spirit level up to the roof line plumb and mark on the level the height.
Measure to said mark on the level and transfer to the board.

 

[roofman]

hold against the shed and mark with a pencil..works every time

 

[eLuSiVeMiTe]

hold against the shed and mark with a pencil..works every time

Only if there's no overhang.
Though I'm a firm believer in the method of hold and mark/scribe. Reduces the fup factor

Flat roof I tend to overhand. Ping a chalk line and cut of with the track saw. Far easier when the brickie have build the building as a parallelogram.

 

[gaz1]

theres no point just cut it level and then put your roof sheet over it

 

[roofman]

Only if there's no overhang.
Though I'm a firm believer in the method of hold and mark/scribe. Reduces the fup factor

Flat roof I tend to overhand. Ping a chalk line and cut of with the track saw. Far easier when the brickie have build the building as a parallelogram.

This also

 

[eLuSiVeMiTe]

This also

Yup. Best way to negate the 100Mm rule.

Nothing worse than manuvering a board up to find its 100mm shy. queue lots of curses.

 

[sardine]

Lesson is don't buy a cheapo digital angle finder off eBay , store it in a shed for 3 years, then expect it to work when you want it to.

 

[eLuSiVeMiTe]

Lesson is don't buy a cheapo digital angle finder off eBay , store it in a shed for 3 years, then expect it to work when you want it to.

Never bothered with them. Framing square does what I need and doesn't break. with a couple of these makes it repeatable every time.
(can't find round ones for some reason) https://www.ebay.co.uk/itm/Johnson-Brass-Stair-Gauge-Set-Two-Attaches-All-Framing-Carpenter-Squares-/311130453945?ul_ref=https%3A%2F%2Frover.ebay.com%2Frover%2F1%2F710-53481-19255-0%2F1%3Fff3%3D4%26pub%3D5574631662%26toolid%3D10001%26campid%3D5338243305%26customid%3Df878f57119ca7642a377673bb5f39d94%26mpre%3Dhttps%253A%252F%252Fwww.ebay.co.uk%252Fitm%252FJohnson-Brass-Stair-Gauge-Set-Two-Attaches-All-Framing-Carpenter-Squares-%252F311130453945%26srcrot%3D710-53481-19255-0%26rvr_id%3D1846515550296%26rvr_ts%3Dbac9ac3d1680ada1d71425ddfff89130&ul_noapp=true

Set 500mm on the blade and 207mm on the tongue and set the ferrules for repeat cuts at 22.5 degrees.
Use a straight edge on the blade for longer runs.

 

[Parm]

For a shed is it really critical to get 15 degrees?

 

[addjunkie]

Go the the paper shop and buy a plastic school protractor. Mark your angle and extend the lines. Its a shed, no need to over think these things

 

[fixerupper]

For stuff like that two straight bits of 3x1 with a bolt and a wingnut to adjust for the angle then project that angle using a snap line ....

 

[colnerov]

Or use a speed square. -

 

[MBB]

Just use simple trigonometry.

 

[eLuSiVeMiTe]

Or use a speed square. -

View attachment 167578

I do.
Mainly used when I cba to get the mitre saw out for square cuts with the skil saw but useful for the odd angle.

 

[roofman]

Just to prolong this overly complicated angle conundrum our smart phones have angle finder apps...just saying