RPA Calculations

[Gary Prentice]

 

Also, I may be wrong but it doesn't say whether to calculate to the nearest 25mm or round up to nearest 25mm. Or at least I haven't been able to find it. What you think Ed?

 

I was told to round down:confused1:

[John Shutler]

In my opinion and going by some of the above posts its very easy to over complicate things. A practical approach and some thought about rooting conditions and the surrounding area can achive alot more than a calculated RPA however you work it out. kinda off topic but certainly relevant

[daltontrees]

In my opinion and going by some of the above posts its very easy to over complicate things. A practical approach and some thought about rooting conditions and the surrounding area can achive alot more than a calculated RPA however you work it out. kinda off topic but certainly relevant

 

That's probably me that has appeared to over-complicate. But that misses the point. By trying to simplify RPAs, Annex D makes it more complicated than it is, and introduces unnecessary errors.

 

Personally I think it's pants that 5837 starts off from a presumed circular RPA and then requires justification for deviation from a circle. It should require justification of circles, particularly since in nature these circles never happen.

 

Biut it sits the box-ticking processes of planning for there to be circles, and opens the door to pseudo-arboriculturists. The only beings inconvenienced are the trees.

[Chris at eden]

I try not to.

 

BS 5837 is guidance and shouldn't be slavishly adhered to. As with all things trees each one is different. Roots will grow where they will. That is where conditions are favourable, and they grow much further out than 12x the diameter of the trunk. Working out a suitable RPA for any particular tree is about applying common sense and a sound professional opinion on the likely distribution of the roots. The ability to justify your RPA is key. BS 5837 is a good starting point, but it is not the entire answer.

 

Ed

 

yes all of that is get. My issue is with the use of annex D as its not clear whether you round up, down or to the nearest.

[Chris at eden]

That's probably me that has appeared to over-complicate. But that misses the point. By trying to simplify RPAs, Annex D makes it more complicated than it is, and introduces unnecessary errors.

 

Personally I think it's pants that 5837 starts off from a presumed circular RPA and then requires justification for deviation from a circle. It should require justification of circles, particularly since in nature these circles never happen.

 

Biut it sits the box-ticking processes of planning for there to be circles, and opens the door to pseudo-arboriculturists. The only beings inconvenienced are the trees.

 

I tell you what is over complicated. Those ridiculous over complicated multi stem calculations. What was wrong with the 10 x the basal diameter. Much easier to work out.

[daltontrees]

I tell you what is over complicated. Those ridiculous over complicated multi stem calculations. What was wrong with the 10 x the basal diameter. Much easier to work out.

 

Sometimes there is no basal diameter, just stems coming straight out of the ground and spreading all-roads. Willows come to mind. Lime coppice regrowth. A few Lawsons etc.

[Gary Prentice]

yes all of that is get. My issue is with the use of annex D as its not clear whether you round up, down or to the nearest.

 

We were told to round down in class. Why? I never thought to ask at the time.

[daltontrees]

We were told to round down in class. Why? I never thought to ask at the time.

 

And the TOs were probably told to round up.

[Chris at eden]

We were told to round down in class. Why? I never thought to ask at the time.

 

I find that odd as every other measurement is rounded up!!!

[Gary Prentice]

I find that odd as every other measurement is rounded up!!!

 

I'm sure that I remember correctly, because I'd always rounded up myself.