The Complete Guide to Roof Trusses: Design, Cost, Framing & More

When it comes to roof trusses, you need to consider everything from design to cost to the pros of using trusses instead of stick framing a roof. If you’re looking for a complete guide for roof trusses, then you’ve come to the right place.

You can use the links below to navigate throughout the guide:

1. Pros of Using Roof Trusses Instead of Stick Framing

2. Pricing Roof Trusses    

3. How to Order Trusses

The Pros of Using Roof Trusses Instead of Stick Framing

The pros of using roof trusses drastically outweigh the pros of stick framing. Sure, there may be an instance where stick framing is your only option, and that is understandable. But 99% of the time, a roof truss is going to give you so much more.

Here are the pros of trusses:

-Roof trusses are actually engineered – all of our trusses have an engineer seal on them which means they have met universal standards.

-Trusses are built in a controlled environment out of the elements of weather. This means the building process isn’t affected by rain or snow.

-Trusses span greater distances without having to be supported.

-Trusses are manufactured with computer-controlled saws, leading to greater accuracy, tighter fits, fewer mistakes, and less lumber waste. It’s simply more exact.

-We waste very little lumber when we build our roof trusses, which means we save more on lumber per truss we build. Try doing that with stick framing.

-Trusses are built on the ground and then lifted into place on existing walls. This eliminates more chances for people to fall and experience an accident.

Why would someone use stick framing?

There are a few reasons why builders go with stick framing versus roof trusses:

-The roof and ceiling can be attached to the same member.

-Steep hip roofs can be constructed easier by stick framing.

-Last minute changes can be made one piece at a time with the framing.

-To construct half stories built into the roof that have large dormers or shed roof style openings out of the roof.

Misconceptions of Stick Framing:

Stick Framing Is Cheaper – FALSE

Many builders also think that stick framing is cheaper than using engineered roof trusses. This is a common misconception because a builder hasn’t looked into buying trusses and typically assumes that trusses are more expensive. This is simply not true. We’ve seen similar houses built side-by-side and trusses allow a builder to build quicker and cheaper.

Stick Framing Can Be Faster – FALSE

Side-by-side comparisons have been completed and roof trusses win the prize for speed. Wood trusses are manufactured in a warehouse away from weather elements, which means rain or shine trusses can be built and then shipped out to a worksite. Also, our trusses are manufactured using computerized systems so the process is quicker and more exact.

Click the video below to watch a comparison on SBC’s site:

stick frame versus trusses video

Time comparison: component framed house (including roof trusses) took 152.1 man hours to complete compared to 373.5 hours for the stick framed house. It took 2.5 times LONGER to complete the house by stick framing.

Stick Framing Uses Less Lumber – FALSE

Since we exactly manufacture our roof trusses with computer software and systems, we’re able to use less lumber than a stick framed roof and there is literally no waste. Stick framing is not an exact method so there is more waste throughout the process of framing.

Lumber comparison: a stick framed house used 20,643 board feet of lumber while a component framed house (including roof trusses) used only 15,052 board feet of lumber. That is 25% less lumber, which means more money in your pocket as the builder and more money in the pocket of the homeowner.

Pricing Roof Trusses – What Cost Can I Expect for Wood Trusses?

Of course, price is probably what you’re most interested in because cost is everything when it comes down to building a structure. Whether you’re a contractor or a builder yourself, you need to know the cost of trusses to determine whether it’s a good purchase.

So, how much will my roof trusses cost?

[*we cannot provide an exact number without further consultation – these are general benchmark prices]

truss diagram for house layout

Let’s consider pricing for a simple structure – a 26’x40’ gable style house.

-This house will have a gable roof and a 16’ center area with a cathedral ceiling over the living and dining room areas.

-The roof pitch will be 5/12 with a cathedral ceiling at a 2.5/12 slope.

-The overhang will be 2’ around the whole house

-The trusses on the ends of the house will be drop top gable trusses

Here are the trusses we’ll need for this gable style house:

-12 common trusses

-2 drop top gable end trusses

-7 scissor trusses

Now let’s run that amount trusses through an estimate based on the average cost per lineal foot (which varies year-to-year, and even month-to-month in some cases).

12 common trusses x 26’ span = 312 lineal feet x $4.00/ft = $1,248.00

2 drop top gable      x 26’ span = 52 lineal feet x $5.00/ft = $260.00

7 scissor trusses     x 26’ span = 182 lineal feet x $4.50/ft = $819.00

Truss subtotal = $2,327.00

At this point we haven’t factored in tax and delivery cost.

Tax is anywhere between 5 and 10% depending on the location of your building site. If we figure a 10% tax for the job, then you would add $177 to the total cost of the trusses.

Then delivery varies based how far we need to haul the trusses from our warehouse. We like to handle the entire package for you because we use a special trailer designed to haul trusses to your job site.

To finish our quick estimate without a delivery cost, we’ve reached a total of:

$2,559 total for wood roof trusses

Factors that Affect Truss Pricing and Cost:

Truss span: this is the distance of the bottom chord of the truss from outside (overhang) of bearing wall to outside of the other bearing wall. The span, in short, is the length of the bottom of the truss. Some spans have a lower rate per foot than others.

For example, if a truss has a span of 26’ then the bottom chord can be built with two boards – 16’ and 10’ – which allows for no scrap and waste and is the most efficient for price savings.

Now if you order a truss with a span of 26’4” then a 10’ board is exchanged for a 12’ and there will be 1’8” of scrap left over even though the truss only expanded by 4”. Of course, we can accommodate any project, but we recommend keeping span to an even number, especially if you want to save on the entire total of trusses.

Overhang: the overhang of the truss is horizontal distance from the end of the bottom chord (or wall) to the end of the top chord of the truss. The top chord can have two cuts: plump or square. The typical overhang for residential is between 16 inches and 24 inches. Again, this length can be adjusted to fit the need of the truss.

If the overhang extends beyond 24 inches, say to 30 inches, then a 2×6 top chord for the tail section will be required to handle the additional overhang.

Roof Pitch (Slope): the vertical rise of the top chord per 12 horizontal inches is the roof pitch or slope. For example, 4/12 pitch means 4 inches of rise in 12 inches of run.

The steeper the roof, the more expensive the trusses get because the longer the boards get and the more roof area increases. You will also incur additional costs because it is much harder to deck and shingle a roof that is 12/12 pitch versus a 4/12 roof.

Truss Spacing: this is the distance between trusses. The standard roof truss spacing is 2’. Almost all residential trusses use this spacing.

There is a misconception that spacing trusses every 16” on center is better because it will be strong than the average 2’. While this can be true, it is not always accurate unless in some high stress situations. The issue is that the truss that is spaced 16” is usually designed lighter and handles less load than those spaced every 2’. So you will need more trusses for 16” spacing which will likely mean higher costs.

For shop and barn trusses, the typical spacing is 4’ on center, and in some cases even 8’ and 10’.

Amount of Trusses: the more trusses you need, the cheaper the price is per truss because we must still run one truss through our entire process. So whether we’re building one or 10, we still need to design it, build it, and then deliver. This is why bulk is always better from a cost standpoint.

Design Loads: the amount of weight a truss needs to support per square foot is important. This includes all of the roofing material and ceiling along with loading for construction purposes, and then environmental factors (such as wind and snow). It’s crucial that we factor in the proper truss load.

How to Order Roof Trusses Successfully:

Ordering trusses isn’t as easy as ordering other wood products, but we will outline everything here that you need to successfully order trusses and make the process simpler for you.

So, what do you need to provide to order roof trusses?

The best way to order: provide a roof and floor plan. We can better guarantee the right fit if we have the dimensions of the floor and roof.

Beyond the plans, here are the details you need to provide:

  • -Location of your project
  • -Type of building and its function
  • -Size of the building or the type of truss, span and quantity
  • -Truss spacing
  • -Roof pitch
  • -Overhang, tail, or soffit width
  • -Loading / roof and ceiling material
  • -Are we matching an existing roof?

Why Do We Need the Location of Building Site?

Geographic information is key for us to know environmental loads, such as snow and wind. Each location varies in how much wind and snow it receives. Of course, the majority of areas we service incur consider amounts of wind throughout the year, so it’s important that we know exactly where the trusses will be installed so we can build the best truss system for your project.

Why is the Function of the Building Important?

Knowing the function of the building allows us to identify proper codes and parameters we must work within for that specific structure. It’s as easy as telling us the trusses are for a house, shop, pavilion, hanger or anything else. From there we’re able to enter the codes and parameters into our design software and correctly manufacture the right trusses for your job.

Why Do We Need the Building Layout?

All of our roof truss quotes start with a layout. If you can tell us the size of your structure and the truss spacing (distance between trusses) then we can tell you how many trusses you will need.

You can certainly figure out the number of trusses on your own if you wish, but we still ask for a building layout so we can see how much area the trusses will cover. We also need to know the spacing for trusses so the layout of the trusses will be correct for your structure.

Why is the Type of Truss Important?

There are many types of trusses available, so it’s important that we know the type of trusses you need. Basically we are asking if you need any gable trusses or not, and if so, the amount of gable trusses you need.

A gable truss sits on the end wall of a structure and has vertical studs every 2 feet or 16 inches. A gable truss isn’t structural and needs a continuous bearing support underneath such as a beam or wall.

Gable trusses are more expensive than common structural trusses because more lumber is required. However, gable trusses are much better for finishing up the gable ends of buildings.

Why the Roof Pitch?

We need the roof pitch because we need to know the slope/angle of the roof. Most of the time a roof pitch is referred to by inches of rise and run. So for example, a 6/12 pitch is 6 inches of rise for 12 inches of run (horizontal).

Why is Overhang Important?

First, overhang is the distance from the end of the bottom chord of the truss (or wall) to the end of the the top chord. Or it’s the distance away from the wall to where the top chord extends out.

This is what the soffit is attached to or pieces tying back against the wall. A standard overhang is 16-24 inches, but the overhang can be any length you wish.

If the overhang exceeds 2.5 feet, we will need to use a larger top chord for the overhang, typically a 2×6 top chord for the truss. We can also build a cantilever for the overhang, which is where the bottom chord of the truss continues beyond the wall.

Why Consider Truss Loading?

Truss loading is important because we need to know the load on the trusses and what the trusses will be required to hold. This is crucial for truss design because otherwise the trusses may not be built to handle the appropriate load.

Typical residential loading covers standard decking and shingles/metal, along with the sheetrock on the ceiling. However, if you plan to use clay tiles on the roof, then we’ll need to know that so we can design the trusses to withstand a heavier load.

Let’s say you’re planning to build a pole barn with only purlins and metal attached to the top of the truss, while leaving the trusses exposed with no ceiling sheetrock. In this case, the truss loading is less so the cost of the trusses is less as well.

Are We Matching an Existing Roof?

If you’re not building a new, free-standing structure, then we need to know so we can match the existing roof. In order for us to match the current roof, we need to know the following: the truss span, the heel height, and the total height of the truss at the middle, or an accurate measurement of the roof pitch.  

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