• line up.
• If you are using copper couplers, you cannot tap them, so you'll have to insert a tight-fitting implement (a broom handle, for example) and very carefully bend the nipple into position without affecting the round shape.

Installing a catwalk

Some people like to install a catwalk when they mount their solar collectors, to make life easier when it comes to maintenance, repairs and general inspection. It isn't really necessary, as even the heaviest snowfall (or iced-on snow) will melt off once the collectors get working, but it does mean you can get a head start on things by scraping snow off, as well as allowing you to keep the collectors clean, in good repair and uncluttered by anything that happens to blow in and get stuck behind them!

If you do decide to install a catwalk, make sure it is well below the bottom of the collectors. If you live somewhere with heavy snow, remember that it will slide off the collectors and pile up on the catwalk, so leave some extra space.