If you are going to install solar collectors on your home's roof, take a trip up there to inspect the mounting location before you try to lift the collectors into place. You need to check a variety of important factors and you don't want to find yourself in a situation where you have the collector ready to be bolted into place, but the site is inappropriate!

• The array is best mounted as far up the roof as possible. It's easier to attach to the roof and reduces the amount of snow that could collect behind the equipment.
• Check for shadows and obstructions. Chimney stacks, tall trees, antennae, and other buildings could all cast shadows on your roof, some of which you may not have considered when calculating the solar window.
• Check for power cables. Solar collectors contain solar fluid , which conducts electricity very easily, so you do not want to work anywhere near power lines. If there are lines too near the optimum mounting position, consider having them moved before you install the collectors.
• Check the roof itself. Repair any damaged or worn materials before you try to mount the collectors.
• Check the roof structure. Most collector arrays aren't heavy enough to be a real problem on an average house but it's not a mistake you want to make – having fluid-filled collectors drop through your attic is a heavy price to pay for not checking that the roof will bear the load. And since you'll be walking around up there, you don't want to fall through, either!
• If you're installing an ICS system, be doubly careful. ICS tanks can be extremely heavy and you must be absolutely sure your home can carry that weight. If you're not qualified to make the decision, consult an architect or engineer and install roof braces if needed.

In general, you should always cover the areas of the roof where you will be working. Laying down planks or plywood will protect the materials: shingles are tougher than wood shake and tiles, but they can still be damaged.

You should always try to do roof-work early in the day, especially on shingle roofs. As the sun heats the shingles, they warm and become more prone to damage.

Finally, it's worth installing a pair of temporary roof jacks and a plank at the collector mounting location, where the bottom of the array will be. Not only does this mark the optimum spot, but it provides a place to stand while working and also prevents the collectors from sliding while you secure them.