Installing a house lot of spouting:
Cut out the spouting into 5-yard (5 M) sections by running a 32-teeth to the inch hacksaw through the front and into the bottom. Continue this cut with a pair of straight tinsnips. Then try and get the straight tinsnips into the back of the spouting and if not all the way through finish with a sharp carpenters wood chisel to cut the final section of the cut out. Repeat on the other side of the damaged area and remove the spouting out of the brackets. Remove all old brackets and any nails left in the fascia and sweep off with a broom.
At the highest point where the fall is to begin usually over the top of a wire entry point on the front of the house place your first plastic or metal bracket. Place a nail under this bracket and measure up from the bottom of the fascia board marking this measurement on the opposite corner. And then drive a 3-inch (75 mm) nail below this by about ½-inch (15 mm) to see if the house will have fall to this point if it is still fairly level.
Take your building string line and tie it off between the two nails you have placed, it stretches so you can pull it really tight. Grab the ladder and move to a point midway between these two nails and using a spirit level check to ensure you indeed have a little bit of fall towards the first down pipe position.
Continue falling smaller sections in this way towards the down pipes. Make it so on the longest sides you are falling towards both ends in which case all you have to do is place your string line and either leave it as is if enough fall to one end or rather it is best practice to simply lift this point up to the point where a bracket is hard up under the roof and then you will utilize all of your hard work to have the water rushing out of these longer sides.
If putting up steel spouting the brackets are placed every yard (1 M) apart. And if installing plastic spouting the brackets go up much closer according to the manufacturers specifications.
A good plastic spouting system can be placed almost level fall wise and this makes for a nice finish against the house.
If installing steel spouting you will be able to buy premade angle sections from your local sheet metal shop. For the best practice of doing all joints on steel spouting see instructions under heading Repairing rusted out steel spouting: