Custom Fan Plate

What a fan plate joins

A fan plate ties together the four timbers at the middle of a king post truss with struts: the bottom beam, or tie beam, the king post that rises from it, and the two struts that come up from its foot to the top chords on either side. One plate holds all four: a bar along the beam, an arm up the king post, and an arm up each strut, with bolts through every one. You set the struts down onto the beam or up onto the king post, and the designer draws their cuts to match. For struts that meet each other with no king post between them, use the custom strut fan plate. If a catalog size fits, our fan 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 bottom beam's height and the king post's and struts' widths.
• The struts' angle: 3/12 to 24/12, or 15° to 65°.
• Plate: 12" to 60" along the beam and 8" to 48" tall, from the bar's bottom to the top of the king post arm. The strut arms reach up to 36", within that outline.
• Arms: the bar, the king post arm, and the strut arms each 2" wide or more, up to their timber's size. The bar sits centered on the beam or raised toward its top, with square stops at the neck if you like.
• 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 on each side of the bar, in the king post, and on each strut.
• Ends: square, clipped, rounded, or pointed, with sharp or rounded inside corners.

The designer opens on our catalog F4 plate on surfaced 6x6 timbers with the struts at 12/12, 45°: 32" wide and 18" tall, with 5/8" bolts, three on each side of the bar, two in the king post, and two on each strut, 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.

Open or filled between the arms?

Open is how our catalog plates are cut, and it shows the timber between the arms. Filled covers those corners with steel. On a truss outdoors, water can collect behind a filled plate there, so most exterior trusses are better open.

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.