How do you get the panels straight?

[Ramjam]

I find it very difficult to line the panels up straight on the roof, what tools and techniques do you employ?

 

[goodwilld]

A good eye, sorry, a string line along the bottom run to get a visable referance, sometimes you have line it up with the front edge of the roof regadless on how it looks down the edge of the roof. No roof is true square.

 

[SolarCity]

Fit your brackets at both ends of your runs, making sure you measure accurately from either the ridge or the eaves. Then run a line between the two and fit your brackets to these lines - this will ensure that your rails are straight. When you've done this, make a mark on the panel and ensure it lines up with the rail.

 

[1billy wiz]

unless you have a laser unlike me!

how do you find measuring verticals of the edges bigsy?

 

[pjcomp]

The way that works for us is to spend a bit of extra time getting the first rail straight and true. Then you've got a baseline to get the other rails straight and true. First panel, same - an extra minute to get it square, then the rest of them fall into place. Once we cracked that it took a good hour off a 16-panel install.

PJ

 

[SolarCity]

It's not just a case of getting them straight or level. It's getting them to follow the line of the roof. It can be tricky but I have found that installing a panel at both ends of the array and then using a string line between the two helps. Take a look how the line looks and adjust it to suit the roof - making sure it looks ok at the top of the roof AND the bottom.

 

[northernsun]

Difficult one to answer. With some of the jobs I have done it has been more art than science and back when I was learning I was fortunate to have a bloke who was an old school roofer and I worked for a company that would let us take as much time as needed.
As mentioned above its all in the prep, if you dont get the begining right you will more than likely be fannying around at the end. Even then, with a roof thats all over the place you might just have to go with what looks the best and throw the measurements and straightness out the window! I have done jobs where the edge of the array is not parralel with any of the roof edges-top, bottom or edge but the array looks right on the roof- I hate jobs like this!
A tool that I find useful is a big builders square, a fold out one with about 1.5m edges at 90 degs, this along with a line.
In general, spending the extra time at the begining is the best tip!
trying the panels on both sides/top and bottom before you throw then all on is good too.

 

[MorganPVI]

Get the 1st four in (8x2) measure the diagonals and ensure they match. If you take the time to do the first 2 or block of 4 right you can bang the rest in making small adjusments by eye. Getting the rails square is good, but never yields consistant results, getting the panels to run like the tile line is the only way to make the array look right. We've had rails and roof achors set up true, absolutely perfectly square, banged on the panels and it's running out on the 3rd panel, don't think i've ever worked on a square roof!!

 

[IronLiver]

I know this is an old thread but this has been bothering me more and more recently especially given the short days, as we always seem to be fannying about in some respect, regardless of how much time is spent setting up the rails. Often the first row will (appear to) go in nice and straight and then the bottom row will start to run out by the third panel despite the fact that the panels are all tight against the clamps. There seems to be some variation in panel width too with some odd sharp panels we have had being 2-3mm wider than others, whilst this doesn't happen often it can throw the lines out. It always seems worse when you're on the roof but the fact that most panels have lines running down them makes the visual tolerance very tight. Some of the problem also seems to be the flex in the rail when you tighten the clamps which then gives once the person holding the panel in place releases.

I like BiggsSolars suggestion of installing a panel at either end then running a string line (we use this method for the anchors having learnt the hard way not to trust the tile or batten line at the outset) but was wondering whether this would be acheivable by other means, maybe using cruciform connectors to attach a short length of rail at 90 degrees at the far end then stringing across to the first panel? I may try this tomorrow to see. Surely this must be the only reliable method of getting a true line across the top?

Todays job was a pain in the arse as we'd set the rail up at a uniform distance from the gable end, run a line from top to bottom (marking all four rails) as a starting guide for the first panels on each of the two rows. Three panels in we scrapped that idea, realigned the first panel by eye as the top row was diving, by the time we came back on the second row the last panel was bang on the original mark! It was probably me using a point of reference that was not square but I just keep thinking that there must be a better way. I dread to think what would happen if we had to do multiple rows with a 20mm gap in between over a run of say 40 panels. By the end you could easily be a foot out!

Any suggestions would be gratefully received.

 

[SolarCity]

Sometimes it is a good idea to start in the middle too, especially if you have a lot of panels to install.

 

[dansk]

Plumb line is the best method for us, put the first panel on, tie a line from the rail - around the bottom edge of the panel - then walk across to the otherside and pull the line tight to the edge of the panel and it very easy to see if the panels on the wonk or not - it only needs to be a few mm out to make life difficult

 

[DomB]

I asked a similar question a while back & from one of the suggestions we now clamp a 4m rail to the top or bottom of the first panel then take a walk to the bottom of the garden and line up that rail with the tile-line / ridgeline / gutter etc. Often we leave that rail clamped on whilst adding the next panels, it helps the line up. We always try and start on the bottom row too, dropping the panels on top is that much easier than pushing them from underneath. And starting in the middle seems good to minimise the error that still manages to creep in.

We use the same rail placed perpendicular to the fixed rails on the roof to get the rail-heights as equal as possible. I almost find getting rid of any height-differences between the panels more difficult than getting them straight

 

[JulianC]

We've developed a fairly good eye for setting out the first panel. One of us will secure it in position while the other will eye it up from the scaffold platform. Pointless trying to be too accurate with mm perfect panels against a roof that is probably several inches out of square but we usually find that lining the panels up against the ridge is the best bet - your eye will generally see the run of the ridge as horizontal, regardless of what the eaves or verges are doing. We generally know if we're on the wonk by the 2nd or 3rd panel, in which case it's a fairly quick job to slacken the clamps off and tweak (helps if you've got 3 hands). Doesn't matter if the rails run square or not, the next panel is simply aligned with its neighbour top and bottom and clamped up. Never fitted more that 8 in a row though....

 

[dansk]

I agree with JCDC regards to rails, as long as they are level with each other then they can be as wonky as you like.

 

[bumcrack]

Assuming you can get the rails looking true to the roof, a good trick is to screw some self drilling screws at the top rear of the first module, same distance down each side. Don't screw then in all the way, leaving about 15mm out. lay the module so these screws ride on the top edge of the top rail.
On big modules screws will probably be 300mm down each side.


Assuming you got the two screws spot on, the panel will be true 90 deg to the Top rail, the rest of the panels will follow this due to the nature of the clamps.

It also frees up hands as you fit the first set of panel clamps.