What is the maximum truss spacing?

Author: Prof. Rocio Schulist PhD  |  Last update: Sunday, November 16, 2025

Place trusses anywhere from 4 feet to even 12 or 16 feet apart, depending on the roofing material used. Work closely with an expert to ensure the truss spacing for your pole barn roof will support your roofing material.

What is the maximum distance between trusses?

Metal-plate-connected wood trusses shall be spaced no more than 24 inches (610 mm) on center and designed for all applicable dead and live loads.

Can trusses be 24 inches apart?

There is no set standard spacing, but 24 in. O.C. is common. Spacing is generally chosen such that the sheathing edges will fall at the centerline of the trusses. As a result, truss spacing usually divides evenly into a common plywood sheet (8 ft.).

Can you space trusses 4 feet apart?

Depending on your builder or building designer, the usual range is anywhere from 2′ on center to 10′ on center with the majority of builder's either using 4′ or 8′ on center or a mix of the two.

What is the maximum spacing for rafters?

The standard roof rafter is cut from a two-by-ten piece of lumber, but two-by-eights and two-by-twelves are also common, depending on the loads and lengths of the rafters. The space between roof rafters can range from 12 to 24 inches, with 16 inches being the standard.

Measuring Rafter Spacing

How far can a 2x6 truss span without support?

The distance a 2×6 can span is determined by the species, grade, location, use, load, and spacing. Based on building codes, a 2×6 can span anywhere from 2'-1” to 20'-8” depending on the affecting factors. Ceiling joists don't normally have the same load restrictions, and so can span greater distances.”

What is the code for rafter spacing?

What Is The Standard Roof Rafter Spacing? The standard roof rafter spacings measured on-center are 12″, 16″, 19.2″, and 24″. The International Residential Building Code (IRC), which is the basis of most North America's building coide, identifies these standard industry measurements.

How many feet should be between roof trusses?

Place trusses anywhere from 4 feet to even 12 or 16 feet apart, depending on the roofing material used. Work closely with an expert to ensure the truss spacing for your pole barn roof will support your roofing material.

Which is better, rafters or trusses?

Consider your budget, desired timeline, and design preferences. If you prioritize a one-of-a-kind look and have some flexibility in time and cost, rafters might be the way to go. However, if speed, budget, and a traditional design are your top concerns, trusses are a great option.

Can pole barn posts be 10 feet apart?

The standard distance between pole barn columns is 8 feet. However, depending on who you choose for your post-frame builder, column spacing may vary between 6 feet through 10 feet. Very rarely do we see columns that are spaced 12 feet apart.

Should trusses be 2x4 or 2x6?

The vast majority of trusses utilize 2x4 dimensional lumber but webs can vary from 2x3 up to 2x12 lumber depending on the design. The grade and species of lumber used for webs is typically different from the chords of the truss to drive economic efficiency.

What is the spacing between trusses called?

Bay: The space between two adjacent trusses is commonly referred to as a "bay." Trusses are structural elements that consist of triangular units, and they are often used in the construction of roofs and bridges.

Do trusses need to line up with studs?

In most situations, the trusses/joists bear on the double 2x top plates of the wall assembly below. The most direct load path would be to always align a stud (or studs if necessary) directly below each truss/joist.

How many trusses for a 30x30 garage?

The formula is truss count = ((roof length × 12)/24) + 1 . This equation will help you determine how many trusses your roof needs. For example, if your roof is 30 feet long, you will need 16 trusses.

What is the distance between two adjacent trusses?

Answer: The space between two adjacent trusses is called a bay.

How far can attic trusses span without support?

How far can an attic truss span? Attic trusses can span up to around 90ft, it's worth considering that long spanned trusses are more challenging to deliver, erect, brace and install efficiently.

Is it cheaper to buy trusses or build them?

There are several reasons: Roof trusses are built in volume, allowing truss manufacturers to take advantage of bulk discounts on raw materials. Contractors often cannot access these types of discounts, making it more cost-effective to buy pre-made trusses. Roof trusses save time in labor.

What is the most economical truss span?

Flat Truss: The most basic and affordable option, with spans of up to 6 meters/19 feet. King Post Truss: Simple and cost-effective, with spans of up to 10 meters/32 feet.

Which style of roof truss is the strongest?

The king post truss is one of the strongest designs and can support very heavy loads. It consists of two vertical posts connected by a horizontal beam at the top. 2. The queen post truss is similar to the king post truss, but it has an additional beam running between the two vertical posts.

What is the maximum spacing for roof trusses?

As a guide, the spacing of roof trusses can be kept 1 / 4 of the span up to 15 m and 1 / 5 of span for 15 - 30 m spans of roof trusses.

What is the best spacing for trusses?

In general, the wider 24-inch spacing is the most economical for residential construction.

Do roof trusses need support in the middle?

Unlike rafters, trusses transfer all their load to the outer bearing points, so they don't need support from interior room partition walls. This design efficiency offers more flexibility in interior layout and potentially reduced costs.

What is the maximum distance between rafters?

Roof rafters shall be spaced either 16 inches or 24 inches apart (on-center (o.c.). The roof design is based on a simple gable end roof with the ridge line at the center of the building width, or a sloped shed type.

How many trusses do I need for 40 ft?

Truss count = ((roof length * 12) / 24) + 1

The simplest form of this equation is to take the length of your roof and divide it by 2. For example, if your roof is 40-feet long, it will need a total of 20 trusses.

What is the spacing for truss rafters?

However, typical roof truss spacing means that they are usually 400mm (16 inches) or 600mm (24 inches) from centre – this means from the centre of one truss to the centre or the next truss.

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