Deck Building in Morrison, CO

Morrison’s building guide for uncovered residential decks and porches sets out ledger attachment, footing, guard, and stair details in more depth than most homeowners expect from a deck project. It also predates the town’s current code edition, which means part of building a Morrison deck correctly is knowing which of the guide’s numbers to confirm directly with the Building Department rather than take as final.

Plan Submittal Comes Before Anything Gets Built

A building permit application for a Morrison deck requires 2 sets of plans and 2 plot plans showing the deck’s dimensions and its position relative to the existing house and the property lines. The application has to specify the decking material and size, joist size and spacing, beam size, post size and spacing, rim joist size, and lag-bolt size and spacing, along with which of the guide’s standard construction details will be used for the framing. We prepare that full spec sheet before submittal rather than filing a bare sketch and hoping the details get worked out during review.

Ledger Attachment Is Where a Deck Either Holds or Fails

Where the deck attaches to the house, Morrison’s guide requires approved flashing at the ledger and non-corrosive lag bolts spaced a minimum of 16 inches apart, positioned to penetrate the rim joist or wall studs rather than just the exterior sheathing. Attachment to a cantilevered floor section or over a masonry veneer is flagged in the guide as a condition that may need an engineer’s approval rather than the standard ledger detail. We identify which attachment condition a given house presents before framing starts, since retrofitting a ledger connection after the deck is built is far more disruptive than planning for it up front.

Footings and Posts Follow a Published Detail, with One Real Gap

The guide’s footing detail calls for an 8-inch minimum diameter concrete pier with an anchor bolt embedded a minimum of 7 inches into the pier, and requires the post to be decay-resistive if its base sits less than 8 inches above finished grade. Beam splices must occur over a post with at least 1½ inches of bearing, connected with a non-corrosive metal post-to-beam or post-anchor connector.

What the guide does not state is a specific frost depth for footing excavation — it is a 2006-IRC-era document, and frost depth for footings is set by the foundation table in whichever residential code edition is currently adopted, now the 2024 IRC. We do not publish a frost-depth number we cannot trace to a current, sourced page; we confirm the required footing depth with the Building Department before any excavation begins.

Guardrails and Stair Geometry Are Spelled Out in Detail

A guard is required on any deck surface more than 30 inches above grade or the floor below, with a minimum guard height of 36 inches and openings sized so a 4-inch diameter sphere cannot pass through the guard. On the sides of stair treads, that opening limit tightens to a 4-3/8-inch sphere, reflecting the different geometry of a stair guard versus a flat-run guard.

Stairs carry their own detailed spec: minimum 36-inch width, maximum 7¾-inch rise, minimum 10-inch tread run, with no more than 3/8 inch of variation in rise or run across the full flight. Open risers are allowed only where the opening is less than 4 inches, and a nosing of ¾ to 1¼ inches is required where risers are solid and treads are less than 11 inches deep. Stairs must be illuminated, and composite decking such as Trex may require 4 stringers rather than the standard count for a solid-lumber tread.

Handrails Apply Once a Stair Reaches Four Risers

A continuous handrail on at least one side of the stair is required once a flight has 4 or more risers. The top of the handrail must sit between 34 and 38 inches above the stair nosings, with a gripable cross-section between 1¼ and 2¼ inches for a non-circular rail, positioned at least 1½ inches clear of any wall or other surface. Handrail ends have to return to a wall, a post, or a safety terminal, following the same handrail-termination detail used in the residential code generally.

An Under-Deck Escape Window Has Its Own Clearance Rule

Where a basement emergency escape and rescue window sits under a proposed deck, Morrison’s guide allows it as long as the deck’s framing lets the window fully open and provides a clear path to a yard or court of at least 36 inches in height — increasing to 6 feet 8 inches where the window serves a walkout basement or opens onto a patio. On any deck project that will sit over or near a basement egress window, we check this clearance during design, before joist layout locks in a height that would block the window’s required path.

How We Sequence a Morrison Deck

We start by confirming the setback situation — Morrison allows decks, along with porches, stairways, and similar features, to project into a required yard setback by up to 33 percent of the required setback depth, down to a minimum of 4 feet from a side lot line — and by identifying the ledger attachment condition the house presents. Plans and plot plans go into the permit application with the full framing spec the guide requires, and we confirm current frost-depth and footing requirements with the Building Department before footings are excavated.

Framing follows the submitted detail, guards and stairs are built to the height, sphere, and geometry limits above, and any basement escape window near the deck footprint is checked against its clearance path before decking goes down. The project closes out with the inspections the Building Department calls for on the permitted scope.

Common Questions

What plans does Morrison require to permit a new deck?
2 sets of construction plans and 2 plot plans showing the deck’s dimensions and its position relative to the house and property lines, along with a full framing spec covering decking, joists, beams, posts, rim joist, and lag-bolt sizing.

How high does a Morrison deck need a guardrail?
Any deck surface more than 30 inches above grade or the floor below needs a guard at least 36 inches high, with openings sized so a 4-inch sphere cannot pass through.

Does Morrison’s deck guide state a required footing depth?
No. The guide gives a footing diameter and anchor-bolt embedment but does not state a frost depth, since it predates the town’s current code edition. We confirm the current frost-depth requirement with the Building Department before excavating.

How far can a deck project into my required setback in Morrison?
Decks, along with similar features like porches and stairways, may project into a required yard setback by up to 33 percent of the required setback depth, down to a minimum of 4 feet from a side lot line.

Talk to Us About Your Project

Tell us your home’s ledger attachment situation, how high the deck will sit above grade, and whether a basement escape window falls under the planned footprint, and we will build the plan set Morrison’s permit process requires.