Planning estimate · Herriman, Utah
Deck railing cost calculator
Priced by the foot, with the part that decides whether the job is simple: how the posts are fixed to the frame. A guard has to take a 200 pound push, and that load goes into the framing, not into the decking.
What is behind the number
What decides the price of a deck railing
A guard looks like trim and prices like structure. Wood runs roughly $35 to $55 a linear foot installed in this region, composite and powder-coated metal $55 to $95, and cable or glass $140 to $240. On a deck with forty feet of open edge, that is the difference between about $2,000 and about $8,000 for the same length of the same deck.
The number that decides whether this is a straightforward job is not on top, it is behind. IRC R312.1 requires a guard to resist a 200 pound concentrated load at the top rail, and that load travels through the post connection into the framing. A post nailed or lag-screwed to the face of the rim joist is relying on fasteners in end grain, which is exactly where fasteners pull out. On decks from Herriman’s first building wave, that detail is common.
The other thing worth knowing before you spend anything: below 30 inches to the lowest grade, the code does not require a guard at all. Plenty of people still want one, for a small child or a dog, and that is a good reason. It just means you get to choose the height and the infill rather than being told.
Material, per foot
Wood at the bottom, composite and metal in the middle, cable and glass at roughly three times the wood rate. This is the single biggest lever on the page, and it changes nothing about how safe the guard is.
The post connection
Through-bolted with tension hardware is correct and cheap to leave alone. Notched over the rim is common and weaker than it looks, because the notch removes the post exactly where the leverage is highest. Nailed or lag-screwed to the outside gets redone whatever else happens.
How many edges are open
An attached deck loses one long side to the house; a freestanding one has all four. That difference alone can be 40 per cent of the length, and long shallow decks have more perimeter per square foot than square ones.
Stairs
Stairs have their own rules: a graspable handrail 34 to 38 inches above the nosings, and the triangle formed by tread, riser and bottom rail is allowed a 6 inch sphere where everywhere else it is 4 3/8 inches. Each flight is priced separately.
Cable and glass need better posts
Cable is tensioned to hundreds of pounds and glass panels are heavy. Both need end and corner posts braced properly and spaced closer than a wood guard would need, or the cables sag out of code spacing within a year.
Tear-off
Taking the old guard off and disposing of it is real money and it is why a retrofit costs more per foot than the same guard on a deck being built now.
What pushes it higher
- Cable or glass rather than wood, at roughly three times the cost per foot.
- Posts that were nailed or lag-screwed to the outside of the rim joist.
- A freestanding deck, where the guard runs all four sides instead of three.
- More than one stair flight.
- Lighting run through the posts or the top rail.
- A long shallow deck, which has more perimeter per square foot than a square one.
What brings it down
- Wood or composite rather than cable or glass.
- Posts that were already through-bolted with proper tension hardware.
- Keeping sound posts and changing only the infill.
- A deck at 30 inches or less, where no guard is required at all.
- Doing the guard alongside other deck work, so tear-off and set-up are shared.
- Leaving the gate, the lighting and the drink cap out.
Turn the estimate into a real number
Send a couple of photos, rough dimensions, and the height down to the lowest corner. You will get a straight answer about the permit, the guard and what the ground is likely to want, before anyone talks about boards.
What people ask about this
How high does a deck railing have to be?
IRC R312.1 requires a guard at least 36 inches high on the deck itself. On stairs the handrail sits 34 to 38 inches above the line of the nosings. Both apply where the walking surface is more than 30 inches above the grade below.
How far apart can the balusters be?
Close enough that a 4 3/8 inch sphere cannot pass through anywhere in the guard. The one exception is the triangle formed by the tread, the riser and the bottom rail on a stair, where a 6 inch sphere is allowed. An inspector will carry the spheres and use them.
Do I need a railing on a deck under 30 inches?
No. IRC R312.1 turns the guard requirement on above 30 inches, measured to the grade below, and Herriman uses the same 30 inches for its permit exemption. Below it a guard is a choice, and a reasonable one if there are small children or a dog, but it is your choice rather than the code’s.
How much does deck railing cost per foot?
Roughly $35 to $55 a foot for wood installed, $55 to $95 for composite or powder-coated metal, and $140 to $240 for cable or glass. A retrofit onto an existing deck runs a little above a new build because of tear-off and whatever the old posts need.
Why does my railing wobble?
Almost always the post connection rather than the rail. Posts nailed or lag-screwed to the outside of the rim joist rely on fasteners in end grain, and end grain does not hold. The fix is blocking behind the post and through-bolts with tension hardware, and it is not the line to leave out.
Do I need a permit to replace a deck railing?
Replacing a guard in kind is normally maintenance rather than new structure, so usually not. If the deck itself is changing, or the guard is going onto a deck that never had one, it is worth one call to Herriman’s Building Division on 801-446-5327 before starting.
Is cable railing worth it?
If there is a view, it is the one material that genuinely gets out of the way. It costs about three times a wood guard per foot, and most of what you are paying for is the structure that keeps it tight: braced end posts at closer spacing, without which the cables sag out of the 4 3/8 inch spacing and the whole point is lost.
Is this a quote?
No. It is a planning estimate. The line most likely to move is the post connection, because nobody can tell how the posts are fixed without looking underneath. A photo from below usually settles it in a minute.