When Roofing a House, What Goes On First? (Colorado Springs Install Order)

Key Takeaways

• The deck goes on first, then drip edge at the eaves, then underlayment, then drip edge at the rakes, then shingles starting from the bottom.
• Shingles always install bottom up, not top down, so each row overlaps and sheds water.
• Ice and water shield is required by Pikes Peak Regional Building Department in the first 24 inches of eaves and at all valleys.
• The ridge cap is the last shingle to go on.

You will hear contractors talk about "starting from the bottom" or "starting from the top" of a roof, and both can be technically right because they are talking about different things. Shingles install bottom up. The roof system overall installs from the deck up. Here is exactly what goes on first, in order, on a real Colorado Springs roof job.

Step 1: The deck

If you are doing a full roof replacement, the existing shingles and underlayment get torn off first, all the way down to the roof deck. The deck is the structural wood layer that holds everything else up, usually 7/16 inch OSB or 1/2 inch plywood in newer Colorado Springs homes, or 1x6 boards (skip sheathing) in homes built before about 1970.

The deck gets inspected. Any wet, rotted, or hail-damaged boards get replaced. Decking replacement is one of the most common "supplements" on insurance claims because you cannot see deck damage until the old roof is off.

In some older Old North End and Bonnyville homes, we find decking that does not meet current code at all. We replace that section before going further. Local building inspection in Colorado Springs requires sound deck under the new roof.

Step 2: Drip edge at the eaves

Drip edge is the L-shaped metal flashing that runs along the bottom edge (the eave) and the gable edges (the rakes) of the roof. The piece at the eaves goes on first, before any underlayment. This order matters: water that gets behind the underlayment can still run down and over the drip edge instead of soaking into the fascia board.

Pikes Peak Regional Building Department code requires drip edge on all eaves and rakes. Some older Colorado Springs roofs were installed without it, and rotted fascia is the result.

Step 3: Ice and water shield

Ice and water shield is a peel-and-stick membrane that prevents water from ice dams or wind-driven rain from getting under the shingles. It goes down before standard underlayment, in specific locations:

• The first 24 inches up the slope from every eave (per local code in the Colorado Springs climate zone)
• All valleys, full width
• Around all penetrations (vents, chimneys, skylights)
• Sometimes the entire roof on low-slope sections or in particularly storm-prone areas

This is one of the most important parts of a roof in Colorado Springs because of how often ice dams form on north-facing slopes during freeze-thaw cycles. Skipping it is a code violation and a future leak.

Step 4: Standard underlayment

The rest of the roof deck gets covered with synthetic underlayment (or 30-pound asphalt felt on budget jobs). Underlayment is the secondary water barrier between the deck and the shingles. It also smooths over minor irregularities in the deck and gives the shingles a clean surface to bond to.

Synthetic underlayments like GAF Deck Armor, Owens Corning ProArmor, and Tyvek Protec hold up to UV exposure (useful when weather delays the shingle layer by a day), tear less easily than felt, and stay flat in heat. They cost more. They are worth it in Colorado Springs.

The underlayment laps over the ice and water shield, runs up the slope, and overlaps each row above by at least 2 inches per code.

Step 5: Drip edge at the rakes

The rake drip edge goes on now, over the underlayment, on the gable edges of the roof. Yes, the eave drip edge went on under the underlayment and the rake drip edge goes on over. This is correct per the IRC, and it is the order that sheds water correctly at each edge.

If you see drip edge installed on top at both the eaves and the rakes, that is a sign of a rushed install.

Step 6: Starter strip

Before any visible shingle goes on, a starter strip runs along the entire eave. Starter strip is a special pre-cut shingle with a continuous adhesive bead along the bottom edge. Its job is to seal down the bottom edge of the first row of visible shingles and to fill the gap between shingle cutouts at the very bottom of the roof.

Skipping starter strip and using upside-down shingles is an old habit some crews still use. It does not meet GAF or Owens Corning warranty requirements and leaves the bottom row vulnerable to wind uplift, which is a real issue in Colorado Springs.

A starter strip also goes up each rake on most architectural shingle installs to seal the gable edge.

Step 7: First course of shingles (bottom row)

Now the visible shingles start, and they install from the bottom up. The first course sits on top of the starter strip, fully visible, and gets nailed per the manufacturer's nail pattern. (Six nails per shingle in the Colorado Springs wind zone. See our post on roofing nails for the full breakdown.)

Each subsequent course goes up, overlapping the course below. Each shingle covers the nails of the shingle below it, which is what makes a shingled roof watertight. If you reverse the order, water runs into the nail holes and the roof leaks immediately.

Step 8: Step flashing and counterflashing

Wherever the roof meets a vertical wall (a chimney, a dormer, a parapet), step flashing weaves into each course of shingles as they go up. Each piece of step flashing laps over the shingle below and tucks under the shingle above. Then a counterflashing piece tucks into the masonry above to cover the top of the step flashing.

Chimneys done well in Colorado Springs have new step flashing on every roof replacement, even when the brick is fine. Reusing old flashing is a frequent source of post-install leaks.

Step 9: Valleys

If the roof has valleys, the shingles meet there. Two ways to handle it:

• Closed cut valley: Shingles from one slope run across the valley and shingles from the other slope cut to meet them. Common, fast, looks clean.
• Open valley: A metal valley liner (W-valley or similar) runs the length of the valley, and shingles trim back to expose the metal. More expensive, sheds debris better.

Most Colorado Springs installs use closed cut valleys. We use open valleys on high-debris locations (under pine trees on the west side, for example) where leaf and needle buildup would otherwise clog the closed valley.

Step 10: Penetrations

Pipe boots, vent caps, attic fans, skylights, anything sticking up through the roof gets installed in coordination with the shingle courses. The boot or flashing weaves into the shingle pattern, with the shingles above covering the upper portion of the flashing and the shingles below sitting on top of the lower portion.

Step 11: Ridge cap

The ridge cap is the very last shingle to go on. Ridge cap shingles are special pre-cut pieces (or hand-cut from 3-tab shingles on budget jobs) that bend over the peak of the roof and cover where the two slopes meet. On a roof with ridge ventilation, the ridge vent goes on first, and then the ridge cap shingles install over the ridge vent.

A poorly installed ridge cap is one of the most common wind-uplift failure points on a Colorado Springs roof. Make sure your contractor uses real ridge cap shingles and installs them with enough nails to hold against 60-plus mph winds.

Step 12: Cleanup and magnet sweep

After the last shingle is on, the crew should sweep the yard, driveway, and gutters with a magnetic roller to collect dropped nails, walk the perimeter with a tarp to catch any remaining debris, and haul off the tear-off material. Then the homeowner walks the property with the crew foreman to spot-check.

Why does the order matter so much?

Each layer of a roof has one job, and the order is what makes them work together. Underlayment depends on drip edge being under it. Shingles depend on underlayment being under them. Ice and water shield depends on going on before underlayment. Ridge cap depends on the field shingles being on first.

A crew that skips a step or does them in the wrong order can still produce a roof that looks fine for a year or two. The problems show up in year three or year five, usually after a major storm event, and the failures get attributed to the storm instead of the install. We see this all the time on second-opinion inspections in Colorado Springs.

What about hail damage to existing roofs?

If you are getting a roof replacement because of hail damage, the install order is identical. The only difference is that the insurance claim covers the work, and the contractor coordinates with the adjuster on scope. See our hail damage page for how that process works.

Need a roof done right?

We do every roof in Colorado Springs in this order, with quality underlayment, hot-dip galvanized ring shank nails where they belong, real ice and water shield in the right locations, and a magnet sweep at the end. Call (719) 657-6893 or book online. Free written estimate same day.