Offset measurement.

[mike-c]

Quick question, does anybody have an easy way to measure an offset for rainwater or plastic piping. My problem is that I have quite a few rainwater down pipes to do tomorrow and normally the offset to go between the gutter and wall is quite short so it can usually be lined up by eye then measured. The down pipes tomorrow are between 800mm and 1mtr from the gutter. Is there a quick method where I can measure from the centre of the rainwater drop to the centre of the down pipe and be able to get a size for the pipe in between the 135 degree bends?

 

[Howsie]

Measure edge to edge.

 

[mike-c]

And is that measurement the correct size for the pipe in between?

 

[Megaflo-Experts]

The pipe between can be calculated. With pythagoras theorm:

Square root of (2 * The distance between the pipes squared).

Eg if horizontal distance between down pipe and outlet is 100mm, then the length of pipe required between the 135 sockets is:

SQR(100*100 + 100*100) = 141.42mm

It's not as bad as it looks!

 

[mike-c]

That looks a good answer but I am afraid it will need to be explained in easier terms for an old codger like me

 

[Megaflo-Experts]

Essentially you have a triangle - which in my example is 100 across horizontally, and 100 down and you need to calculate the diagonal.
Look up pythagoras or try this website Pythagoras-Calculator * Mathematics-Tool.
Enter your horizontal distance in 'a' and 'b', then 'c' is your diagonal.

Hope that makes sense!

 

[nicro3]

Makes very little sense agreed standing up a ladder and shouting Eureka

 

[chris watkins]

The pipe between can be calculated. With pythagoras theorm:

Square root of (2 * The distance between the pipes squared).

Eg if horizontal distance between down pipe and outlet is 100mm, then the length of pipe required between the 135 sockets is:

SQR(100*100 + 100*100) = 141.42mm

It's not as bad as it looks!

Could be a fatal floor in an other wise cunning plan - Most rain water offset bends are not 135deg (45) bends but 112.5deg can it still work if not an equilateral triangle ?

 

[AWheating]

or buy 135 bends

 

[Megaflo-Experts]

Could be a fatal floor in an other wise cunning plan - Most rain water offset bends are not 135deg (45) bends but 112.5deg can it still work if not an equilateral triangle ?

Good question!
Yes, it applies to any right angle triangle, so you will need to know the horizontal and vertical distances, then you can calculate the diagonal.
If you only know one of the lengths, it can still be calculated, but it gets more complicated.

 

[nicro3]

Easiest way set out on floor with your measurements b-b or c-c

 

[mike-c]

I was really hoping that someone would just tell me that if the centres between the outlet and the rainwater pipe on the wall was such and such then just add 20 mm or 30 mm or whatever but I guess it is not to be.

by the way the job is now done and all the offsets were different sizes due to the fact that all the soffits were different sizes. Typical joiners.