How do I work this out ???

[SAISAY]

I need to make a rectangular trellis 6 m x 2.2 m in a diamond pattern.
How do I work out the individual lengths of the slats? :?
My brain refuses to work today. I know how many square metres I need and how many I can rip out of a 3 x 2.
I just cannot imagine cutting one length at a time.
LW

[Bleedin Thumb]

I don't believe I'm even answering this.

If your using a 45 deg arrangement it is simple pythagoras rule, ie the square root of 2.2 squared x 2 = 3.1 m

You can work it out more accurately by subtracting the thickness of the surround but I though I'd let you do some work

[SAISAY]

Maybe I should clarify. What I am trying to work out is a sort of materials list e.g. 4 @ 3.1 metres, 4 @ ??? metres.
There must be a way to work out the difference in length from slat 1 to slat 2 and so on.
LW

[Bleedin Thumb]

Are you serious? What you go to all the trouble to make your own lattice and you expect zero waste? If your really hung up about it draw it up to scale and measure them.

My suggestion is just rip a sh!* load of 3.1's an cut down the end slats as you need them . You will still be able to use the off cut.

Well actually my second suggestion is go and order a ready made panel from your nearest trellice supplier.

BTW what sort of timber are you using?

[echnidna]

draw a section up fullsize and measure it after you find pleasant looking angles

[SAISAY]

I would if I could but I can't so I won't.
Nobody up here supplies that kind of stuff anymore.
All I can get is 3 x 5 treated timber in 6 m lengths.
Don't have a ute so need delivery.
Only timber shop here that will deliver is Mitre10 trade and they take advantage of the monopoly.
I intend to rip it down to slats.
Guess I was trying to be frugal.
LW

[Skew ChiDAMN!!]

I reckon it's one of those things every apprentice should build. Once. I could almost guarantee they'll never bother with another one. :U

The first thing you need to work out is what size diamonds you want. As BT pointed out: if they were going to be "squares on their points" then the longest slats would be around 3.11m.

slat_length = √(width_covered²+wall_height²)

How many you need at that size would depend on how far apart they're spaced.

Trying to work out an accurate cutting list is, IMHO, not worth the effort. Personally, I wouldn't even bother trying to calc the length of the slats at each end... I'd just cut a few extra a full length slats and cut 'em to length in situ; the offcuts can be used as the "shortest" slats.

[RufflyRustic]

Hi Little Wolf

Nothing wrong with being frugal.

You could get some popsicle sticks, work out the scale and then build a miniature. that would help with the look of it.

Personally though, I'd approach this by using graph paper to draw up a scaled plan. work out how much timber, rip the strips, start laying it out etc etc etc.

A bit of work, but definitely not impossible and certainly something to be proud of when finished. - Especially if you can't get any trellis where you are.:)

Cheers
Wendy

[DavidG]

Cut all at 3.1.
At the ends the bit you cut off fits at the other end with no waste.

The total number of slats depends on the width per slat and the gap.
Given those figures it is easy to calc the number of slats. Then given the slat thickness you can calc the number of boards required.

Stick the figures up and some one here will calc it.

Have done similar myself when I could not get the timber sizes I required.

[echnidna]

As wendy says graph papers probably the easiest way to go.

The old time diagonal lattice was usually strips 20 to 25 mm wide.
The modern square stuff is about 35mm wide.

I'd think about using 150 x 25 treated pine to cut the strips out of.

[pawnhead]

The treatment only goes a bit past skin deep though.
It was a fiddly job staining and lacquering my lattice, but you'll have the advantage of coating all the strips as a bundle before assembly.

edit: get a cheap electric staple/nail gun to assemble it. They're not that dear and you'll have another fixing tool for your box. :wink:

[Bleedin Thumb]

Actually a good way to assemble them is to make a template with nails on a sheet of ply - just slot the slats between the nails .....saves all that measuring. As pawn head points out the treatment isn't much chop if your using LOSP treated pine so go Tan E or ACQ however you will still have to do a number on the timber if you don't want it rotting very quickly. Also 6 x 2,2 is a whopping lattice panel , do you have a crane to handle it when its finished? IE how about 2 x 3m panels?

[Blocklayer]

Is this calculator http://www.blocklayer.com/StudsAngle.aspx for working out stud lengths at an angle any good for your trellis pieces?

And to work out angles and triangles and things, try this http://www.visualtrig.com You can see the triangle shape and just enter the sides or angles you know to redraw it with all the others worked out
.

[SAISAY]

Thank you Blocklayer, this was just what I was looking for. :2tsup:
And the other people, thank you for pointing out the "Skin Deep' part, one thing we did not think about. Even the green stuff goes black pretty quickly up here in the tropics.
Actually, the total area is 6 m x 2.2 m in 4 sections. I agree a 6 metre wide panel would probably be a heavy job for 2 old timers :D.
Back to the drawing board.
Wendy, looks like I will have to do the graph paper job first, thank you for reminding me. :2tsup:
LW