Quiz-type question

[kme]

I`ve just been asked a question, and I have the answer - as does one other member of the forum.

But I thought, out of interest, and knowing how much searching I had to do to find it......how many others know.

If you`re putting Solar PV on a roof - how close to the edges of the roof can you go with the panels?

Please say where you get your answer from ]

KME

 

[Apache]

300mm - the width of a roof ladder. Source - my brain.

 

[Catalin Neagu]

300-mm

Its the approximate distance away from the edge where the wind loading on the array significantly drops away. So for those not doing the wind calc this is deemed a safer distance. As you get closer or overhang, building control may get involved.

KOKO

 

[kme]

I see the logic.......though you`re both wrong!

Nice try.....next guess is?

 

[Catalin Neagu]

I see the logic.......though you`re both wrong!Nice try.....next guess is?

Thanks KME

Ive spend 1 hour to find this answer ..........:^Oheadbang

 

[Apache]

450mm - roof ladders are wider than I thought!

 

[Andy™]

150mm?

just a guess. i know just about nothing about solar PV

 

[kme]

keep guessing gang..........................

 

[paul b b]

Flush with the side of the roof

 

[kme]

erm.......no!

I was asked this morning; and went through my course notes from the NIC; and checked the powerpoint presentations they use, too - no mention of ANYTHING.

But, I DID find a reference in another book - one of our members had an argument with his boss about this.....I think he won.

 

[paul b b]

600mm

 

[philbas]

The notes I have fron the Logic Certification course just state.

Where practicable the modules should ideally be no closer tham 500mm to the roof edge and if less than 300mm then additional consideration needs to be given to fixing points, wind lift and wind noise as well as rain overshoot beyond the guttering

They also say it must not be within 1 metre of the roof line.

So my guess is they can extend to the edge of the roof.

 

[kme]

Now, see. That info doesn`t gel with mine; which was found in a publication designed for installers, surveyors & architects ..............

 

[kme]

Okay.

So the thoughts seem to have dried up a bit.

The answer is:

The distance from the edges of the roof should be equal to, or greater than, five times the distance between the plane of the roof; and the array. i.e. however far the panels "stand off", times five.

Next question. If I (and others) have been assessed as "competent" to design & install solar PV to the standard required by MCS.....why isn`t this covered in the course I did? (NICEIC)

 

[steptoe]

well,

on my course we were informed 450mm all round,

but, this doesnt actually seem to be supported in any form of actual documentation anywhere,

so it seems like it was just a rule of thumb judgement by the tutor....

The answer is:

The distance from the edges of the roof should be equal to, or greater than, five times the distance between the plane of the roof; and the array. i.e. however far the panels "stand off", times five.

this would actually probably tie in with Catalin's reasoning,

distance away from the edge where the wind loading on the array significantly drops away

I dunno, :C

 

[kme]

The publication I quoted to you this morning does go into such things mate (I`ll get that across to you.........), I suppose they could all have been correct; without knowing what the distance off the roof is............

 

[steptoe]

Ive measure a few different brackets,

the closest I can get to the roof is 50mm with the panel mounted,

the average seems to be 70mm+ , most brackets we have are 60mm to the bottom of the rail, from the tile height, so take 60x5 = 300mm minimum, + rail,

 

[SPECIAL LOCATION]

Well I would have said.......

As near to the edge as you can stand without falling off!!!!!!!!!!

But arriving late to class looks like I already missed handing me homework in!

:coat

 

[steptoe]

how big are yer feet?

and how much wind is there?

and how much of you is there to catch the wind?

 

[SPECIAL LOCATION]

AND!!!!!!!!!!!!

How high is the roof?

and

how 5h1t scared are you standing close to the edge????????????

:^O]