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Gutters & Downspouts for the DIY’er

Construction How-To, Gutters July 6, 2009 Matt Weber

Install it yourself to protect your home and save on labor cost.

In general, gutters and downspouts are far from the most glamorous feature of a home, but these systems are the unsung heroes that protect your house from water damage. By collecting roof runoff and diverting it away from the building envelope, gutters and downspouts help to prevent damage such as wood rot, mold and mildew.

The house shown in this article was built in 1978 and only had a single gutter and two downspouts installed at the front, with nothing on the rear. As a result, during a rainstorm the water was cascading off the rear of the roof and pounding a trench along the foundation wall, where it was seeping through the ground and migrating through the cinderblock, as evidenced by water stains on the interior of the wall. By installing a gutter and a couple of downspouts, the water is channeled away from that troublesome trench and diverted across the yard and away from the house walls.

Professional installation of metal gutters usually involves specialized equipment used to form gutters from sheet metal at the job site. One advantage of professional installation is that the gutters can be installed with a seamless system, which provides the best protection against leaks. Plus, the gutter contractor will be the guy working atop a ladder at the roof line, which is a big selling point for homeowners who aren’t comfortable with the heights of roof work. However, for do-it-yourselfers who don’t mind working on a ladder, you can save considerable labor costs by installing a gutter using the sectional systems available at retail outlets such as Lowe’s Home Improvement Stores.

For this particular job, I picked up the materials at my local Lowe’s, which distributes Amerimax aluminum gutter systems. The first step is to sketch out your gutter system on paper so you can quantify the various components required. Measure your roof line and wall height to calculate the number of 10-foot sections of gutter and downspout you’ll need. I was working with standard 5-inch gutters with a “K” profile. Next, account for end caps, seamers, inside or outside corner pieces, downspout elbows and end drops. You’ll also need mastic for sealing the joints, downspout bands to fasten to the house, and sheet-metal screws to connect the downspout sections. To hang the gutter, you can choose from a variety of fastener types. I chose to use hidden fasteners that are held to the fascia with screws. Here’s how a homeowner can install a gutter, protect their home and save some cash by doing it themselves …

Getting Started

When installing a gutter system, be prepared to spend a lot of time working at potentially dangerous heights. Because so much roof work is involved, I highly recommend attaching a ladder stabilizer to the top of your ladder. I picked up a Werner Ladder Stabilizer at Lowe’s, which proved on this job to be the best 25 bucks I could have spent. Not only does this simple bracket attachment safely prevent the ladder from swaying from left to right while you’re standing on it, but it also provides a 10-inch standoff from the roof line, which makes it easy to access the fascia and gutter without obstruction from the ladder. The stabilizer also rests on the roof, rather than on the shingles, fascia or house siding, so there’s no worry of accidental damage from contact with the ladder.


To begin installation, safely position the ladder on even ground with the ladder stabilizer firmly supported by the roof deck. Climb up to one corner and hook the end of a chalk line at the point where you want the top edge of the gutter to terminate. Unreel the line as you move to the opposite end of the fascia. At that corner, first level the string, and then drop the string about 1 inch per 40-foot run and snap the chalk line. This achieves a slope that helps gravity pull water to the downspout locations. If you have a long run with downspouts at both ends of the gutter, you can slope the gutter from its midpoint toward both of the book-ending downspouts.