A deck on the Front Range is not the same structure as a deck in a mild climate. It carries snow, it takes hail, it sits under ultraviolet exposure that increases with elevation, and it is attached to a house whose foundation and framing move with the soil. Every one of those conditions shows up in how the deck is built — or in how quickly it fails when it is not.
We build attached decks, freestanding decks, covered patios and pergolas, stairs and guards, and we rebuild decks that were framed by someone who treated the ledger as a nailing detail.
The Ledger: Where Decks Actually Fail
The overwhelming majority of catastrophic deck failures are not the decking, the posts or the footings. They are the ledger — the board that fastens the deck to the house — pulling away from the rim joist.
Done correctly, the ledger is through-bolted or fastened with structural screws in a specified pattern into solid framing, with flashing above it that directs water out and over the deck rather than down behind the board. The flashing matters as much as the fastener. Water trapped behind an unflashed ledger rots the rim joist of the house, not just the deck, and that damage is invisible until the deck moves.
Two failure patterns we see repeatedly on older metro decks: a ledger lag-screwed through siding into what turned out to be sheathing rather than framing, and a ledger fastened over stucco or stone veneer with no flashing at all. Both hold fine for years, then let go under a wet spring snow load with people standing on the deck.
Where the attachment condition is questionable — a cantilevered floor, an unclear rim, a veneer wall — the honest answer is often a freestanding deck with its own posts along the house side. It costs a little more in footings and saves the entire argument.
Snow Load and Why Span Tables Matter Here
Deck framing is sized for the load it carries, and ground snow load in this region is not uniform. Metro addresses are designed to one figure; foothill and mountain addresses can be designed to substantially more, and jurisdictions such as Jefferson County set higher design loads with elevation, with the highest ranges requiring design by a licensed professional rather than a prescriptive table.
That changes joist size, joist spacing, beam size and post spacing — not marginally. A deck framed to a flatland spacing at 7,500 feet is undersized, and the way it tells you is deflection under wet snow, then a permanent sag.
We confirm the design snow load for the specific address before sizing anything, because the number follows the property, not the city name on the mail.
Footings and Frost Depth
Deck posts bear on footings set below the frost line, and the required depth is set by the jurisdiction — commonly in the 30 to 36 inch range across the metro, and confirmed at permit rather than assumed. A footing that stops short of frost depth heaves in winter and drops in spring, which racks the frame and opens the joints.
The second issue is the same expansive soil that affects the house. Where clays are active, footing diameter and depth and the connection between post and footing all matter, and a deck poured on a shallow pad because the ground was hard that day will move independently of the house it is attached to.
Guards, Stairs and the Inspection Items
The items that fail inspection most often on a residential deck are predictable:
- Guards are required once the walking surface is more than 30 inches above the grade below, and residential guard height is a minimum of 36 inches
- Guard infill must reject the passage of a 4-inch sphere — this is what rules out widely spaced horizontal cable or baluster layouts that were not tensioned or spaced correctly
- Stair rise and run must be consistent within tight tolerance across the flight; a single odd riser at the bottom is a trip hazard and a correction notice
- Graspable handrail on stairs with four or more risers, with the specified profile — a 2×4 laid flat is not a handrail
- Post-to-beam and joist-to-beam connections made with rated hardware, not toe-nails
None of these are expensive to do right the first time. All of them are expensive to correct after the decking is down.
Wildland-Urban Interface Requirements
On addresses inside a designated wildland-urban interface overlay — a large share of the foothill communities in Jefferson County and the mountain corridor — exterior construction carries ignition-resistance requirements. For a deck that means noncombustible or ignition-resistant framing and decking materials, restrictions on what may be stored or enclosed underneath, and detailing that does not create an ember trap.
This is not optional and it is not advisory. It applies at permit, it applies to alterations and not only new construction, and it materially changes material selection and budget. We check the overlay for the address before quoting a foothill deck, because a wood deck quoted for an address that requires noncombustible materials is not a quote, it is a surprise.
Materials at Altitude
Ultraviolet intensity increases with elevation, and the Front Range combines that with a large daily temperature swing and low humidity. Finishes fail faster here than the manufacturer’s national guidance implies.
- Pressure-treated pine — the cheapest frame and the cheapest deck surface. As a surface it needs cleaning and re-sealing on a short cycle, and it checks and cups if that maintenance lapses.
- Cedar and redwood — better stability and appearance, still a finish-maintenance commitment, and it greys quickly if left unfinished.
- Composite and PVC decking — no re-sealing, and the reason most of our clients choose it. Two things to know: darker boards get genuinely hot in direct high-altitude sun, and boards expand and contract, so gapping and fastening have to follow the manufacturer’s specification rather than a carpenter’s habit.
- Steel framing — increasingly used where a long service life is wanted under a composite surface, and where combustibility is a constraint.
The frame usually lasts longer than the surface. When we are asked to replace a deck surface, we open and inspect the frame first, because there is no sense fastening a 25-year board to a rotted joist.
Covered Patios and Roof Structures
Adding a roof over a deck changes it from a deck into a structure that carries snow load overhead. That means a beam and post design sized for the roof, footings sized for the increased load, and, where the cover attaches to the house, a connection detail that does not compromise the existing roof or wall.
It also changes the permit. A covered structure may trigger setback and lot coverage review that an open deck did not, and in some jurisdictions it is reviewed as an addition. We resolve that at design rather than discovering it at plan review.
What a Deck Project Includes
- Site measurement, design snow load and frost depth confirmed for the address
- Setback, lot coverage and WUI overlay check before design is finalised
- Permit drawings and submittal
- Footings, posts and beam, with rated hardware throughout
- Ledger attachment and flashing, or freestanding design where attachment is not sound
- Framing, blocking and decking to the manufacturer’s fastening and gapping spec
- Guards, stairs, handrail and lighting
- Framing and final inspection
Setbacks, Easements and HOA Review
Before the structure gets designed, two things decide how big the deck can be and where it can sit.
The first is zoning. Rear and side setbacks, lot coverage limits and recorded utility easements all apply to a deck, and a deck built over an easement can be required to come out at the utility’s convenience rather than yours. The rules are set by the jurisdiction the property address actually falls under, which in the metro is frequently an unincorporated county rather than the city in the mailing address.
The second is the HOA. In much of Douglas County, Broomfield and the newer Adams County subdivisions, architectural review runs on its own timetable, has its own rules on material, colour and railing style, and is entirely separate from the building permit. Approval from one is not approval from the other, and the HOA is the one most likely to be discovered late. We check both before drawing, because a design that has to be revised after approval costs more than the review did.
Maintenance and What Actually Fails Here
Front Range conditions are hard on exterior wood in a specific way. Intense UV at altitude, a very wide daily temperature swing, low humidity most of the year and then heavy wet snow loading in spring — that combination weathers a horizontal surface far faster than the same board would weather at sea level.
What that means in practice:
- Finish on the walking surface degrades first, and south and west exposures go before north ones. A stained wood deck here needs recoating on a cycle rather than when it looks bad.
- Fastener heads and end grain are where rot starts, not the middle of a board. Cut ends sealed at install last materially longer.
- Composite does not rot, but it does move, and it gets hot in direct sun. Gapping has to be set for the temperature at install, not to the tidiest-looking spacing.
- Snow that slides off a roof onto a deck is a load and an impact, and it stacks where it lands. On the metal roofs common in the foothills this decides where the deck can go.
- Ledger flashing is the part that fails silently. Water gets behind it, the rim joist rots inside the wall, and nothing is visible until something moves.
Most of the deck failures we are called to look at are not the decking. They are the connection to the house and the fasteners — which is why the parts you will never see again after the first day are the parts worth paying for.
Deck Building by City
Permit rules, inspections and lead times for deck building change from one jurisdiction to the next. Pick your city:
Counties We Cover
Full service-area coverage by county:
Common Questions
Do I need a permit for a deck?
In every jurisdiction we work in, an attached deck and any deck above a specified height require a permit, and a covered structure almost always does. The review checks the structural design, the ledger attachment, guards and stairs, and setbacks. Building without one is the most reliable way to have the deck become a problem at the point of sale.
How long does a deck take to build?
The construction on a typical metro deck runs a couple of weeks, plus a cure period after the footings are poured. The schedule driver is the permit, not the carpentry — review time varies considerably between jurisdictions, and we confirm the timeline for your address before committing to a start date.
Is composite decking worth the extra cost here?
For most clients on the Front Range, yes — because the alternative is re-sealing a wood surface on a short cycle under high-altitude ultraviolet exposure, and that maintenance is what people stop doing in year three. The two caveats are surface heat on dark boards in direct sun and the need to follow the manufacturer’s gapping and fastening specification exactly, since composite moves more than wood with temperature.
Can you replace just the boards and keep my existing frame?
Sometimes, and it is the cheapest good outcome when the frame is sound. We open the surface and inspect the ledger, rim, joists and hardware first. If the ledger is unflashed or the joists show rot at the fastener line, resurfacing over it wastes the boards, so we report what we find before ordering material.
My deck feels bouncy. Is that dangerous?
Bounce is deflection, and it means the joists are spanning further than their size supports, or blocking is missing, or a beam has lost bearing. It is not automatically a safety failure, but it is a signal worth inspecting — particularly if the deck is attached to the house, since the same inspection looks at the ledger, which is where real failures happen.