How To Install Rain Gutters - Part 2

Based on the sketch in Figure 8 this home would need the following components:

Downspout fittings are based on the number of drop outlets (Figure 9).

Figure 9 - Gutter drop outlet

Figure 10 - Downspout 45° elbow

• For ground drainage: Number of 45° elbows (Figure 10) = 3 times the number of drop outlets.
• For drainage directly to sewers: Number of 45° elbows (Figure 10) = 2 times the number of drop outlets.

A flex elbow (Figure 11) takes the place of two 45° elbows.

Figure 11 - Gutter downspout flex elbow style 1

Figure 12 - Gutter downspout flex elbow style 2

The length of the downspout piping is the based on the height of the gutter from the ground.

If more than one length of downspout is needed, always insert the lengths of downspout in the direction of water flow, as shown in Figures 13 and 14.

The blue arrow indicates the direction of water flow.

Figure 13 - Incorrect installation of gutter downspout.

Figure 14 - Correct installation of gutter downspout.

Each manufacturer has a slightly different mounting method or gutter hanger. Some are mounted on the inside of the gutter and are hidden from view, others mount on the outside of the gutter, while others mount through the front face of the gutter itself.

However, in all cases, hangers should be used every 18 inches to 24 inches. At least one downspout strap should be used for every 8 feet of downspout pipe.

The gutter or trough material must slope towards the drop outlet. At a minimum the drop should be 1/4 inch for every 10 feet. Use a chalk line (Figure 15) or a laser level (Figure 16) to mark the slope on the fascia board of the overhang.

Figure 15 - Chalk line

Figure 16 - Laser level