Custom King Post Plate

What a king post plate joins

A king post plate joins the peak of a king post truss: the two top chords, or rafters, and the king post that runs up between them. An arm runs down each top chord and one down the king post, with bolts through all three. The top chords can meet each other, cut plumb, with the king post's top cut to their undersides. Or they can land on the sides of a ridge beam, with the king post running up to its bottom. For a peak with no king post, use the custom peak plate. If a catalog pitch fits, our king post truss plate is ready-drawn in six collections for 3" to 12" timbers.

Sizes this designer makes

• Timbers: 2 1/2" to 15 1/2", entered as measured, in 1/8" steps: the top chords' width and the king post's width.
• Pitch: 3/12 to 24/12, or 15° to 65°.
• Ridge beam: none, or 2 1/2" to 15 1/2" wide and 2 1/2" to 24" tall, with the top chords' top edges set level with its top or below it.
• Plate: up to 36" along each top chord and up to 48" tall, from the peak down the king post. The arms are each 2" wide or more, up to their timber's size.
• Between the arms: open, as our catalog plates are, or filled.
• Bolts: 1/4" to 3/4", in one row or two. You set how many go in each top chord and in the king post.
• Ends: square, clipped, rounded, or pointed, with sharp or rounded inside corners.

The designer opens on our catalog W4 plate on surfaced 6x6 timbers at a 6/12 pitch, the top chords meeting, with three 5/8" bolts in each top chord and three in the king post, square ends, in 1/4" steel. Change any of it.

Where the bolts go

The first question is how far the bolts sit from the ends and edges of your timbers, and from each other. Minimum distances, the default, holds every bolt to the American Wood Council's NDS minimums for softwood: 3 1/2 bolt diameters from the end of a timber, 1 1/2 from its edge, and 3 from the next bolt. That's how we lay out our own plates. Full-strength distances doubles the end distance to 7 diameters and spaces bolts 4 apart, so plates come out larger or with fewer bolts. No minimum distances puts each bolt where you set it. Wood that close to a bolt can split, so have your engineer check that layout. The bolt spacing and edge distance guide explains the numbers.

How it's priced

By weight: the steel in your plate, less its holes, with shipping in the lower 48 built in. There's no charge for design or setup. The price changes as you change the plate, and the price you see is the price you pay. A plate over $500 goes through the quote form instead.

Questions

How many do I need for a truss?

One for each face you plate: one on the front of the truss, or two for front and back.

Can it go over a ridge beam?

Not over it. With a ridge beam, this plate goes on the outside face of an end truss, where the ridge beam ends; it can't go on a face the ridge beam runs past. To carry the ridge beam at the peak, our ridge beam truss saddle is fitted with you after the order, or ask us for a quote on a custom saddle.

Which thickness should I choose?

3/16" is our standard plate and suits most decorative work. 1/4" is a third heavier and stiffer, and 3/8" and 1/2" heavier still. Our plates are architectural hardware, not engineered or load-rated: if a plate is part of how your truss carries load, your engineer decides whether it's suitable and how thick it should be.

The basics

• A36 steel plate, laser cut in our ISO 9001 shop in Texas.
• Holes are cut 1/16" larger than the bolt you choose. Bolts aren't included.
• Enter your timbers' real size, not their name. How to measure a timber.
• Bare steel, or matte black powder coat added in the cart.
• Ships free in the lower 48 states.
• No published load ratings. Ask your engineer, and see what to give them.