Replace Gutters And Downspouts: DIY Steps, Costs & Tips

Sagging seams, overflowing troughs during a Kirkland downpour, water pooling around your foundation, these are the signs telling you it's time to replace gutters and downspouts. Left alone, failing gutters cause damage that goes far beyond cosmetics: rotting fascia boards, eroded landscaping, and costly foundation repairs that no homeowner wants to deal with.

The good news is that a gutter replacement is one of those projects where you have real options. You can tackle it yourself over a weekend with basic tools and save on labor, or you can bring in a professional crew and know the job is done right the first time. Either way, understanding the full scope of work, materials, measurements, costs, and common mistakes, puts you in a much stronger position before you spend a dollar. At Legacy Exteriors, we install gutter systems across the greater Kirkland and Eastside area every week, so we know exactly where DIY efforts succeed and where they tend to go sideways.

This guide walks you through every step of replacing your gutters and downspouts, breaks down realistic costs for both DIY and professional installation, and helps you decide which route makes the most sense for your home and budget.

Before you start: assess, plan, and stay safe

Rushing into a gutter replacement without a proper assessment will cost you time and money. Before you buy a single section of aluminum or schedule a crew, you need a clear picture of what you're working with and what you're replacing it with. Walk the perimeter of your home on a dry day and take a hard look at every part of your current system from ground level before you get on a ladder.

Assess your existing system

Start by checking for sagging sections, separated seams, rust spots, and visible cracks. Look at your fascia boards directly underneath the gutters too. If the wood is soft, discolored, or visibly rotted, you need to repair or replace the fascia before you install anything new, because gutters attached to rotten wood will fail quickly and pull away from the house. Also check whether your current pitch is correct: gutters should slope roughly 1/4 inch for every 10 feet toward the downspout. A tape measure and a simple level can confirm this in a few minutes.

If your fascia needs replacement, handle that repair first. Skipping it is the most common reason a new gutter installation fails within a year.

Note the number of downspouts and where they currently drain. If you've been dealing with overflow, you may need to add a downspout or extend an existing one further from the foundation when you replace gutters and downspouts, not just swap like for like.

Measure and plan your layout

Accurate measurements are what separate a clean installation from one you're redoing in two years. Measure the total linear footage of each gutter run and record the location of every inside corner, outside corner, and downspout outlet. Use the table below as a planning template before you order any materials:

Run	Length (ft)	Inside Corners	Outside Corners	Downspouts	End Caps
Front
Back
Left side
Right side

Add 10% to your total linear footage to account for cuts and waste. Most home improvement stores sell gutters in 10-foot sections, so round your order up to the nearest full section each time.

Stay safe on the ladder

Ladder safety is not optional on this project. Set your ladder on firm, level ground and always keep three points of contact. For a standard single-story home, a 6-foot fiberglass ladder handles most sections without issue. Two-story homes require a proper extension ladder and a second person on the ground to hold it steady. Never lean past the ladder's side rails, and move the ladder frequently rather than stretching to reach the next section.

DIY or hire a pro in Washington

Choosing between doing it yourself and hiring a contractor depends on more than just your comfort with a ladder. The scope of the job, the height of your roofline, and the condition of your fascia all factor into that decision. Washington's wet climate also means installation quality directly affects how long your system lasts, so it's worth being honest about your skill level before you commit.

When DIY makes sense

A gutter replacement is a realistic weekend project if your home is single-story, your fascia boards are solid, and you're comfortable working on a ladder for several hours. You'll save $3 to $6 per linear foot in labor costs, which adds up fast on a larger home. Sectional aluminum gutters are widely available at local home improvement stores, and the tools required are basic: a drill, tin snips, a level, and silicone sealant.

DIY works best when you're doing a straight swap on a single-story home with no fascia damage and no complex rooflines.

Your decision gets harder when the project grows. Multi-story homes, steep pitches, or homes with multiple valleys and angles turn a manageable weekend job into a genuine safety risk and a technical challenge that most homeowners aren't equipped for.

When to call a professional

Hire a contractor when your home is two stories or taller, when you find rotted fascia during your assessment, or when you want seamless gutters instead of sectional ones. Seamless gutters are cut on-site from a continuous roll using specialty equipment that no homeowner owns. They also have far fewer joints, which means fewer leak points over time. When you replace gutters and downspouts on a complex roofline in the Pacific Northwest, a professional crew finishes the job faster, handles the fascia repair in the same visit, and stands behind the work with a warranty.

What it costs in 2026

Knowing your numbers before you start helps you avoid surprises and make a smarter decision about DIY versus professional installation. Whether you're planning to replace gutters and downspouts yourself or hire a crew, the costs break down into materials, labor, and any additional repairs like fascia replacement that come up during the project.

DIY material costs

When you go the DIY route, materials are your primary expense. Sectional aluminum gutters are the most affordable option and are available at most home improvement stores. Here's a realistic cost breakdown for a mid-size home with roughly 150 linear feet of gutter:

Item	Unit Cost	Estimated Total
Aluminum gutter sections (10 ft)	$6-$10 per section	$90-$150
Downspout sections	$8-$15 each	$40-$75
Hangers and brackets	$0.75-$1.50 each	$30-$60
End caps, corners, connectors	$3-$8 each	$40-$80
Silicone sealant	$5-$8 per tube	$15-$25
Estimated DIY total		$215-$390

Your final number depends on gutter style, material gauge, and how many downspouts and corners your layout requires.

Professional installation costs

Hiring a professional crew in the greater Kirkland and Eastside area typically runs $8 to $20 per linear foot installed, depending on home height, material choice, and whether fascia repairs are included. For a 150-linear-foot project, that puts total professional installation between $1,200 and $3,000.

Seamless aluminum gutters cost more upfront than sectional systems, but their longer lifespan and fewer leak points make them a better long-term value for most Washington homeowners.

Copper and steel gutters push costs higher, sometimes reaching $25 to $40 per linear foot for materials and labor combined. Factor in fascia repair at $5 to $10 per linear foot if your assessment turned up soft or rotted wood.

Step-by-step: replace gutters and downspouts

Once your materials are on hand and your fascia is confirmed solid, the actual installation moves quickly if you work in order. This section gives you the exact sequence to follow when you replace gutters and downspouts, from pulling the old system down to connecting the final downspout extension at grade level.

Remove the old system

Start at the downspout. Disconnect it from the outlet at the bottom of the gutter run first, then work upward, removing any straps or hangers holding it to the wall. For the gutter itself, pull out the existing hangers or spikes along the run, then lower each section carefully to the ground. Clean the fascia surface with a stiff brush once the old system is off, and fill any old spike holes with exterior wood filler before you hang anything new.

Install the new gutters

Snap a chalk line along the fascia to establish your slope before you attach a single hanger. Mark the high end 1 inch below the roof drip edge, then drop 1/4 inch for every 10 feet toward the downspout outlet location.

Getting your slope right before you hang the first hanger saves you from pulling everything down and starting over.

Follow this sequence for each run:

1. Screw the first hanger at the high end of your chalk line

2. Space additional hangers every 24 inches along the run

3. Snap gutter sections together and seal every joint with silicone

4. Attach end caps and corner pieces, sealing the inside of each connection

5. Cut the downspout outlet hole with tin snips and press the outlet fitting in

Attach the downspouts

Slide the first downspout elbow onto the outlet, angle it flush to the wall, and screw it in place. Connect straight sections vertically using self-tapping screws at each joint, then finish with a lower elbow that directs water at least 4 feet away from your foundation.

Common problems and quick fixes

Even a careful installation runs into issues over time, and knowing how to diagnose and fix the most common failures will save you from replacing entire sections prematurely. Most problems that show up after you replace gutters and downspouts trace back to a small number of root causes, and nearly all of them have a straightforward fix if you catch them early.

Leaks at joints and seams

Leaking seams are the most frequent complaint after a sectional gutter installation. They usually appear because the sealant wasn't applied to the inside of the joint during installation, or because an older bead of sealant has cracked and pulled away. To fix it, dry the inside of the joint completely, scrape out the old sealant, and apply a fresh bead of silicone or gutter sealant rated for metal. Run a wet finger along the bead to press it flush before it cures.

Never apply new sealant over old, cracked sealant. The new bead won't bond properly and the leak will return within one season.

Gutters pulling away from the fascia

When a gutter section starts to sag or pull away from the wall, the hangers have either failed or were spaced too far apart. Pull out the old hanger, fill the screw hole with exterior wood filler, let it dry fully, then drive a new hanger screw into solid wood roughly two inches from the original location. If the fascia itself is soft under your thumb, the wood needs replacement before any hanger will hold.

Clogs causing overflow

A clogged downspout is usually the first culprit when you see water spilling over the front lip of your gutter during rain. Run a garden hose into the top of the downspout at full pressure. If water backs up instead of flowing through, feed a plumber's auger or a downspout cleaning wand down from the top to break up the blockage.

Next steps

You now have everything you need to replace gutters and downspouts with confidence, from assessment and materials to installation sequence and common fixes. The path forward depends on what your home inspection turned up. If your fascia is solid and you have a single-story home, a weekend DIY project is completely within reach using the steps in this guide. If your assessment revealed rotted wood, a multi-story roofline, or you simply want seamless gutters backed by a warranty, bringing in a professional crew is the smarter call.

Either way, acting before the next heavy rain season in the Pacific Northwest protects your foundation, your landscaping, and your fascia from the kind of water damage that compounds fast. If you want a professional set of eyes on your current system and a locked-in price quote with no surprises, schedule a free gutter inspection with Legacy Exteriors and we will assess your home and walk you through your options.