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Deck railing costs about $28–$48 per linear foot installed in pressure-treated wood, $55–$95 in aluminum and $120–$200 for cable or glass systems. Cost = railing length (ft) × installed price per foot. Worked example: a 16 × 12 ft deck attached along its 16 ft side has 12 + 16 + 12 = 40 ft of open edge; in composite railing at about $70 per foot that is 40 × $70 = $2,800. Guards are required once the deck surface is more than 30 inches above grade, and balusters must stop a 4-inch sphere.
With these inputs:
| Result | Value |
|---|---|
| Installed railing cost | $2,380 – $3,360 |
| Linear footage | 40 ft |
| Cost per linear foot | $70 |
| Posts at 6 ft max | 8 |
| Sections | 7 |
| Materials (~55%) | $1,540 |
| Labour (~45%) | $1,260 |
Guards are required once the deck is more than 30 in above grade; 36 in is the usual minimum height. Each post has to resist a 200 lb outward load, so bolt it through the rim with blocking.
Railing is often a quarter of the whole deck budget, and the figure surprises people because it is priced by the linear foot rather than the square foot. Material choice drives it more than anything else. This works out the railing length you need, the post count, and what each common system costs across that run.
Wood railing typically runs $28 to $48 per linear foot installed, aluminium or steel $55 to $95, cable rail $80 to $150 and glass panel $130 to $240. On a 16 by 12 ft deck that is 40 linear feet of railing, so the difference between wood and cable is several thousand dollars for the same deck.
Thirty-six inches is the residential minimum in most of the US, measured from the deck surface to the top of the rail, and 42 inches is required in some jurisdictions and for commercial work. Guards are required once the deck is more than 30 inches above grade, though building one on a lower deck is common and harmless.
Six feet is the usual maximum, and four to five is better with cable rail because cable tension pulls the end posts inward. The governing requirement is not the spacing itself but the load: the top rail has to resist a 200 pound force applied in any direction at any point, and that load is carried by the post connection into the frame.
Wood and most aluminium kit systems, yes — the work is straightforward once the posts are properly attached. The part that is not DIY-friendly is the post connection, because a railing that looks solid can still fail the 200 pound load test if the post is only screwed through the decking. Bolt posts through the rim joist with blocking behind, or use a rated post mount.
Budget the installed price per foot plus about $5 to $10 per foot to remove and dispose of the old railing. Replacing 40 feet of worn wood railing with composite typically lands between $2,500 and $4,000. If the old posts are only screwed through the decking, expect to add blocking and bolts to bring them up to the 200 pound load requirement.
Measure every open edge more than 30 inches above grade, then subtract door openings and the width of the stairs. A 16 by 12 ft deck attached along its 16 ft side has 12 + 16 + 12 = 40 feet of open edge; a 4 ft stair takes that to 36 feet of deck railing plus two stair rails of about 6 feet each on a typical 4 ft rise.
Multiply the run length by the number of cable rows. Cables are usually spaced about 3 inches apart so a 4 inch sphere cannot push through once they flex, which works out to about 10 to 11 rows on a 36 inch guard. 40 ft of railing with 11 rows needs 440 ft of cable, plus fittings at both ends of every cable in every straight run. Keep posts about 4 ft apart, or add intermediate spacers, so the cables stay tight.
Porch railing is priced the same way as deck railing — per linear foot installed — so the same ranges apply: roughly $28 to $48 per foot for wood, $55 to $95 for aluminium and $80 to $150 for cable. A porch is usually a shorter run than a deck, so fixed items such as the stair rails and any gate make up a bigger share of the total.
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