Install downspouts every 20 to 50 feet along the gutter. The more closely downspouts are spaced along the gutter, the more water can be conducted away during peak rainstorms.
How far apart should your downspouts be on your gutter system? Your gutters should have a downspout around every 30 to 40 feet. This typically means installing downspouts at both ends of a gutter section. Although there are some factors that can affect the total number of downspouts you need for your house.
The general rule of thumb is one downspout for every 20-30 feet of gutter. This may vary depending on several factors such as the pitch of your roof, the volume of rainfall in your area, and the capacity of your gutters.
Spacing. There's a rule of thumb that downspouts should be installed at least every 20 feet along the gutter line. However, this can vary based on the factors we've discussed earlier, such as roof size, pitch, and local rainfall intensity.
A common guideline is that you need one downspout per 40' span of gutter for proper drainage, but this is usually not enough for a 2”x3” downspout. A homeowner should also consider the size of the roof which will factor into how much water is going into the gutter.
A maximum 12 m gutter length served by each downpipe is to ensure effective fall and adequate capacity to discharge all water anticipated during a storm having an average recurrence interval of 20 years.
In general, it is recommended that the maximum length of a gutter with a single downspout should not exceed 30 to 40 feet (9 to 12 meters) to ensure proper water drainage. However, this is a general guideline, and it's always best to consult with a professional gutter installer or engineer for your specific situation.
Allow 1 square inch of downspout cross-section for every 100 square feet of roof area. Place downspouts at least 20 feet apart but no more than 50 feet apart.
Gutter Straps. Where gutter width exceeds 6" or in areas with severe ice or snow conditions, straps are used in conjunction with brackets to provide additional support. Gutter straps should be spaced 30" apart and extend 6" up onto the roof. Brass screws are used to secure the straps onto the roof sheathing.
To calculate the minimum number of downpipes, divide the roof catchment area by the allowable maximum catchment per downpipe. To calculate the average catchment per downpipe, divide the roof catchment area by the number of downpipes.
Downspout drains are usually buried from 12 to 48 inches below the ground to better conceal the drainage system.
5” gutters typically get the 2×3” downspout, so be aware that if you add 3×4” downspouts to 5” gutters, it will look very odd. Since work must be done to add your additional, larger downspout, now would be the best time to switch out to 6” gutters, as well.
Size of the Gutter Drainage Area: As a rule of thumb, one downspout should be placed every 25-35 linear feet of guttering. Depending on the local climate and rainfall intensity, some homeowners may need more downspouts. Many homeowners add extra downspouts to boost the drainage capacity of their gutters.
The cardinal rules for downspout placement suggest that they should be located at every corner of the house and approximately every 20 to 30 feet along the gutter line.
Downspouts must also be sized to handle this level of rainfall. Rectangular 2 x 3-inch downspouts have a capacity of 600 square feet, while 3 x 4-inch downspouts can handle 1,200 square feet. Choosing the 3 x 4-inch rectangular downspouts, we'd need at least seven to handle the expected water flow.
There should be a downspout for every 40 linear feet of gutter – If your gutters don't have enough downspouts, water may overflow and spill onto the concrete pavement. Eventually, overflowing rainwater might even seep into your home's foundation and basement walls.
Where should gutter downspouts be placed? Naturally, the whole gutter system can only be successful if the downspouts are placed in the correct places. Here are some general rules you should follow for proper downspout placement: The general rule is that there needs to be a downspout for every 40 feet of the gutter.
Description. Two (2) Diamond Bands are required for every 10 feet of downspout. Three (3) Diamond Bands are sufficient for a straight 20 foot run.
The spacing between downpipes must not be more than 12m.
Gutter downspouts should extend a minimum of four feet away from the house; however, they may need to extend much further depending on your soil, the slope of your house and local buildings codes.
Connect the top section of downspout to the bottom section by crimping its edges. A special downspout crimper tool will do this, but you can use needle-nose pliers. Crimp all the way around the downspout to a depth of at least 1 inch. Insert the top crimped section into the lower section as far as it will go.
Your new gutters should be installed at a certain angle to ensure rainwater is diverted to the drains. As a rule of thumb, gutters should have a slope of 1/4 inch for every 10 feet.
To get the best draining results from your gutters, we recommend having at least one downspout for 50 feet, and two 2 downspouts for over 50 feet.
6 Inch Gutters Hold 50% More Water Than 5 Inch Gutters
It will also protect plants below the guttering and prevent channels from forming after rainfall.