The Meridian deck guide

Most deck projects in Meridian are somebody's first. The city is Idaho's second largest and grew by more than half again between the 2010 and 2020 censuses, so the majority of houses here went up after 2000 with a back door opening onto graded, seeded ground and nothing else. Ten or fifteen years later the household finally does something about it, and starts from zero.

Where can it go?

Not simply anywhere in the back yard. Meridian subdivision lots carry recorded easements, and they are wider than most owners assume: a strip along the rear boundary, narrower ones down each side, and a wider one on the street side of a corner lot. A structure standing in one is an encroachment, and if the party who holds the easement ever needs access, moving the structure is the owner's problem and the owner's expense.

Your recorded plat is the document that settles where those lines fall, and it is worth having in front of you before the first sketch rather than after. The other constraint is your subdivision's architectural committee. Most Meridian subdivisions have one, and the city's own accessory structure guidance tells homeowners to verify their association's requirements before building. Committees meet on their own schedule, so that conversation is worth opening early. The easements post works through what this does to a back yard.

What goes in the ground

Water in soil expands when it freezes, so the upper ground in this valley rises through the winter and settles again in the spring. Anything bearing inside that layer travels with it. A footing has to reach past it, onto original undisturbed ground, and on a graded subdivision lot the original ground can be a fair way below what you are standing on.

None of this is visible after the first week. The hole is open for a few hours and then it is concrete forever. The footings guide covers the mechanism properly, along with the stair stringer detail that catches people and the concentrated-load cases where prescriptive framing stops applying.

Attaching to the house, or not

On an attached deck the ledger is the most consequential connection in the structure. It carries one end of every joist back into the house, which means it has to be fixed into house framing rather than to the sheathing that framing is covered with, and it has to be flashed.

Flashing is the detail worth understanding, because it is doing something specific. Rain running down a wall has to get past the point where the deck meets it. A metal skirt tucked up under the siding and turned out over the top of the ledger sends that water out over the deck. Without it, the water goes into the joint instead, where it sits against end grain and framing in a spot that never dries and never gets looked at. Wall rot behind a ledger is discovered during demolition, not before.

Where the wall construction is unknown, which happens on Old Town Meridian houses and on older stock in Nampa and Boise, the honest answer is often a deck that does not attach at all: a structure standing free on its own posts and beams beside the house. It costs a little more in footings and framing, and it removes the entire failure category.

The guard is structure, not trim

People choose a rail the way they choose a light fitting, and price it the same way. It is worth knowing what it actually is.

The practical consequence is that a rail retrofit is mostly post work, and post work is the part that quietly disappears out of a cheap quote. The railing guide covers the systems and what each costs by the linear foot.

Choosing the surface

Four realistic options, and the climate decides between them more than the catalogue does. The Boise normals give a July average high near 93 degrees and a January average low around 25 degrees, so timber here takes both a heavy annual ultraviolet dose and a genuine freeze-thaw cycle.

• Pressure treated pine, $32 to $48 per square foot installed. Cheapest, entirely sound, wants a clean and re-coat every two to four years.
• Western red cedar, $42 to $66. Stays flatter, far nicer underfoot on a hot afternoon, takes semi-transparent stain evenly. Same maintenance cycle.
• Capped composite, $55 to $88. No re-coating. The cap resists the fading a bare board suffers. Wants closer joist spacing than wood.
• Capped PVC, $66 to $105. Lightest, best on heat gain, most expensive.

The framing under all four is identical, which is why the installed gap is narrower than the per-board price gap suggests. The materials guide compares them properly, and the finishing guide covers what maintaining wood here involves.

What it costs

Most Treasure Valley decks land between $8,000 and $45,000. A small treated deck close to the ground with a simple rail sits near the bottom of that. A family-sized composite deck with a mid grade rail sits in the upper half of it. A covered outdoor room on a larger Eagle or Star lot goes past $80,000 and stops being a deck project.

Two lines surprise people. Rail is routinely a fifth to a third of the budget, because it is a structural assembly rather than trim. And height costs more than area: the same footprint raised up needs longer posts, larger footings, a full run of guard, and a stair flight with its own handrail and its own footings underneath. Put your own numbers in with the cost estimator, then read the cost guide for what moves each line.

When it gets built

The season runs late March through October in this valley and fills from the front, with May and June booking out furthest. September and October are the quietest good-weather weeks and the easiest time to get a design talked through properly. A winter inquiry still gets a design drawn, committee approval sought and materials ordered for an early spring start, which the seasonality guide goes into.

What a written price covers

A deck quote is mostly a description of things you will never see again, so the useful ones are specific about exactly those things: the footing arrangement, the framing, whether the deck attaches to the house or stands free, the named decking product and color rather than a category, how the rail is priced, and what the stairs land on.

The quote post takes two prices for the same yard apart line by line and shows where a large gap between them comes from. It is usually not margin.

Where to go next

If you know roughly what you want, the cost estimator is the fastest way to a number. If you are still working out the shape, start with the layout guide. If the yard bakes in the afternoon, the shade guide is the one that matters. And if there is already a deck out there that has seen better days, the repair page covers what is worth saving and what is not.