How to Match an Existing Gable Roof & The Truss Design

Adding on to a house or structure is a great way to get more room without building an entire new house! There are several important things to know about matching existing roofs and how to do it depending on what style of roof you have, the roof truss design, and how you want to add on.

Categories of House Additions

There are two main categories that additions fall under most of the time:

  • T-shape
  • Continued

house trusses

gable roof

Either the addition is added to form a T-shape to the house with the ridge running perpendicular to the main house roof, or the addition is continued on the end of the house making it longer with the ridge running the same way as the existing house.

Gable End Addition

Here we will focus on adding length to the end of a house roof. Now once again, there are several ways to add on.

The addition can be wider than the existing house, narrower, or the exact same width. If you choose to go wider or narrower, there won’t be the challenge of matching up exactly to the old roof and the project will be much easier. With the roof pitch the same, it doesn’t matter if the new addition is slightly off in height or lined up front-to-back because you’re going over or under the old roof.

But it is important that the roof pitch is exactly the same as the existing roof because you will see it from one roof to the other if it isn’t.

If you choose to go with the same width, it will be more difficult to execute without a noticeable difference or bump in the roof between the old and the new. 

Let’s dive into a few more details regarding the roof so we can focus on matching each roof and having a seamless project with beautiful results.

First up, an example…

26-Foot Addition Example 

For the first example, let’s say you have a simple 30’x60’ rectangle shaped house with gable style ends and a 2-foot overhang like this:

And you have decided that you want to add on a 26’ garage on the end of the house like this:

And the finished roof plan when you’re done with matching ridge, overhang and soffit lines should look like this:

But wait…

Do you know how your old roof was built?

Was it built with roof trusses or stick frame? Now is the time to check before you start pouring your slab and building your new walls. If you don’t check, you will likely build your new walls the same height as your old walls but there are reasons not to do so.

What are they?

Let’s explore the differences between stick framing and roof trusses, and how they affect your slab and walls:

The Two Different Roof Framing Styles: Stick Frame & Trusses

If your house was built using roof trusses, then it will look like this above the outside wall of your house:

roof truss system

A stick framed roof will have a rafter member looking something like this:

You’ll notice the difference in how the boards are cut to sit on the wall and create overhang.

Wood roof trusses bring the bottom chord of the truss all the way to the outside of the wall, include a small vertical cut (butt cut), and angles back against the top chord of the truss. The top chord smoothly extends out past the wall to create the overhang.

(If the roof truss has a 2×4 top chord, the heel is shorter than if it has a 2×6 top chord as a general rule. The heel height is adjustable in height by changing how tall the butt cut on the bottom chord is.)

The stick framed roof is a different story. 

Since the rafter has no bottom chord to sit on, it must have a birds mouth cut into the bottom side of the rafter so it has a flat place to sit down on the wall. Now the rafter also has a vertical heel cut that instead of sitting above the wall, actually sits down beside the wall. Depending on what size of rafter is being used, the corner of the birds mouth cut and the top edge of the rafter can get rather thin.

Matching the Two Different Roof Framing Styles

This brings us to the point that putting a rafter beside a wood truss or a truss beside a rafter on the same height of wall may not always work. If the stick framed rafter is a 2×6, it typically has just enough heel height after the birds mouth cut that a regular 2×4 truss can sit beside it and match height.

Any rafter bigger than a 2×6 shouldn’t be a problem unless your roof is pitched fairly steep. A 2×4 rafter just doesn’t leave enough height after the birds mouth to match on any roof pitch.

So now the first step to adding on is to determine how your current roof is built and what the heel height is.

Typically, the best way to find out the heel height is through a vent in the soffit or even pulling a piece of soffit down a bit.

Another way would be to pull off some siding at the top of the wall, on the gable end, right where you are going to be starting the addition. Once you can reach the heel, carefully measure the height of it vertically at the outside corner of the wall to within 1/8 inch.

Also determine how the roof was built while you’re looking at it – roof trusses or stick framed?

If the roof is built with trusses, congratulate yourself that you have a good roof and that the project will be easier 🙂 

We can match another truss, and who knows, we may have even built the truss your looking at. And if it was stick framed, don’t lose hope! We can do this together!

Floor & Wall Height Considerations

Now back to wall and floor heights.

If the heel height is too short and we can’t match it, there are a couple things that can be done. If the ceiling of the new addition can be lowered an inch or 2, this gives us room to build a truss to match on the roof top.

Or if the addition is for a garage, a lot of times the floor is lower than the house floor anyway and it can be adjusted up or down to make a regular framed wall come out slightly lower than the existing house wall.

The other option is to make the walls taller than the existing house and just make the new roof higher than the old with a higher ceiling. Going up and higher than the old roof means you don’t have to match exactly anymore which is also easier. However, this may not be the look you want.

Plan Your Roof in Advance – Give Us A Call!

At any rate, this is a great time to call Timberlake TrussWorks about your project at 580-852-3660! (We service Oklahoma, Kansas, and North Texas) 

After reading this article, you will be up on most everything we would tell you! There are a few tricks left in the bag that can be pulled out if for some reason your project doesn’t fall under these general examples.

When you call, we will want to know the heel height and roof pitch and can begin to help you with matching up and getting a design to work. Contacting us at this stage will also give us a chance to stay with you throughout your process. Keeping on top of the details and planning ahead makes it go much smoother for you and us! By planning ahead and knowing your building schedule as well, we can make sure we have the trusses to you on time so when you rip into the existing structure, you don’t have to keep it uncovered for very long.

Matching Existing Truss Worksheet

Want a worksheet to make this easier?

Email us to get your downloadable worksheet: brad@tltruss.com

This is the complete list of details we need for a perfect match. Some of the details will may not be available until the floor and walls are complete. Filling out as much of this worksheet as possible will only speed the process up and make it go that much quicker and smoother.

Thanks for choosing Timberlake TrussWorks for your quality-built trusses and hardware! We appreciate your business!

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Pros and Cons of Trusses vs Stick Framing

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When comparing two things, it’s best to compare apples for apples. If you are trying to decide if you will use Trusses vs Stick Framing, there are things to take into consideration that will make a difference in your decision making.

Although we want to compare apples for apples, some things can’t be compared equally because it’s actually not possible to do it as both trusses and stick framing have some situations where one isn’t an option.

[Read more…]

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Differences Between Trusses & Stick Framing, And Common Misconceptions

stick framing

Stick framing has been around for quite some time. Trusses are relatively new, so naturally trusses are not quite as well known or understood as stick framing. And even if you’ve known about trusses for a while, the industry is changing rapidly, so it’s good to get the latest news and details.

Difference Between Stick Framing & Truss:

Do you know what it means when we talk about stick framing a roof? Stick framing is building the roof on the construction site one piece or board at a time.

It starts with setting ridge and valley beams above the house walls. Then dimensional lumber, called rafters, are cut to fit one piece at a time and shoved up to a framer on the roof that’s balancing on scaffolding who installs the rafters.

Once the roof slope is complete, the ceiling still needs to be framed. This too is all cut to fit on the job-site one piece at a time. The roof and ceiling is literally “sticked” together.

A wood truss on the other hand is a structurally sound engineered building product. When a truss is installed on top of the walls, it builds the roof slope and ceiling at the same time as one structural piece.

Trusses can be designed in all shapes and sizes, and customized completely based on the project. The truss is built within our manufacturing facility and then fitted directly on the job-site. This reduces man hours on the job site, which reduces cost.

We can get everything designed and built within our facility, then ship the truss directly to the site and have it installed in no time.

Learn more about how we price our trusses and the possible designs you can implement.

Example — What Stick Framing Looks Like Compared to Trusses:

stick framing

This first image is from a roof project being constructed using the stick frame technique. As you can see circled in red on the left is a bunch of boards or “sticks” connected together to support the frame of the roof. However, this doesn’t look quite sturdy or safe. And the sticking together of boards is sloppy.

wood truss

Now, this image is from a roof project being constructed with wood trusses. As you can see within the red rectangle, everything is uniform, sturdy and well constructed. Here you have a solid roof structure that wasn’t “sticked” together. Instead, the roof is much more stable, strong and durable.

Here is a quick video showing the installation of trusses (sped up to 2x and 4x normal speed): 

Stick Framing & Truss Misconceptions:

Stick framing is cheaper than trusses. FALSE.

Identical houses have been built side by side different times using the two different methods and every time it costs less to use trusses. See link for information: https://www.sbcindustry.com/fad

Trusses are faster than stick framing. TRUE!

There are multiple instances were comparisons have been done side by side and trusses have always been faster. Here is a video one such comparison: https://www.sbcindustry.com/fad2

Trusses can clear span a great distance. TRUE!

We have built trusses with cathedral that were free spanning 64 foot!

A stick framed roof is more flexible to build what you want. HOW? Where are we talking about flexibility? Is it on the outside roof style, inside looks and walls, or what? I’ll talk more about this below as we need to go more in depth on this one.

Trusses don’t have room inside the webbing for any storage. FALSE.

Tell the truss engineer that you would like some room for storage and specify how much room you would like along with what kind of stuff you would like to store. Webbing can be changed to allow room or else a room can just be built right into the trusses. MiTek truss software automatically adds additional loading into the trusses anywhere a box 2 foot wide and 3 foot tall can fit between the webs.

Can trusses be used for attic area or bonus rooms? True!

This is very commonly misunderstood thing. Trusses can free span quite a distance and still have an attic room built in. Over a garage is a typical example. What’s more, they can allow room for stairs and design the trusses to handle that as well.

Are trusses better then stick framing? DEPENDS.

This questions is a little harder to answer and depends on what is being built. 9 times out of 10 trusses are better but I’ll explain more about that in the next post.

When 2 different things are compared or considered, it is good to compare apples for apples. If you are trying to decide if you will use trusses or go with the stick frame option, there are things to take into consideration that will make a difference on how you decide. So even though we want to compare apples for apples, some things can’t be compared equally because it’s actually not possible to do it as both have some situations where the other technique can’t perform as well.

Are all trusses created equal? NO!

The type of lumber being used to build the truss makes a large difference on how the truss turns out. It also makes a large difference how careful the truss company is when they build the trusses.

Does it matter what type of lumber is used on the truss? YES!

Think about it: the truss is constructed using lumber. The better the lumber quality, the better the truss. KNOW WHAT KIND OF LUMBER IS BEING USED TO BUILD YOUR TRUSSES! This is very important. Some lumber that companies use warps and will give you a bad experience. Most of the lumber we use is a White Fir or Hem Fir which is strong and very stable.

Which is the strongest and most stable, trusses or stick frame? Trusses!

It is a known fact that a trussed roof has less bounce then a stick framed roof. Think about a single board sitting by itself across a gap. It flexes when jumped on right? Now think of that board connected up with other boards in a triangular shape. Much stronger now right? That’s how trusses work.

Why do people still stick frame roofs when they can use trusses?

Stick framing has been around the longest and that’s just what some people know. Just because it has been around the longest doesn’t mean it’s the best though, right? Most people that still stick frame roofs do so because they haven’t learned otherwise or because they are unwilling to change. Or some people stick frame because they received a bad set of trusses from a truss company at one time. We take pride in our work and want every truss to fit perfect. We care about our customers and want them to be happy with what they order from us!

We just stick frame the roof because it’s less hassle and doesn’t take as long as ordering trusses. FALSE!

You will be surprised how easy it is to order trusses. Most phone calls to order trusses take between 5 to 10 minutes on average for a simple project. More complicated projects take a litte longer at times. Stick framing takes much longer than that.

Do trusses have any limitations? Sometimes but not often.

There are some projects that are designed in such a way that trusses just aren’t a good option. This happens most often on a roof with the ceiling following the roof joist or on a few special hip roofs with some unusual features. Most hip roofs are not a problem though.

One of the lines we like tell people are “Try us once and you’ll see just how good our trusses are!” We are quite confident that they will outperform and fit better than any set you’ve ever had. Remember, we can only build trusses to fit as good as the dimensions given to us are accurate. Starting with a squared and level concrete foundation or floor is also just as important for a perfect fit.

Please read our other blogs for helpful information and give us a call when you are ready to get a quote or order your trusses!

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Pricing Wood Trusses for Any Project: A Step-By-Step Guide

We wish we could provide an exact answer to the question – how much will my trusses cost?

Although we can’t provide the exact bottom-line number (without further consultation), what we can provide is a thorough pricing guide to help you understand how wood trusses are priced for homes, buildings and all projects.

Below you’ll learn about the most common truss design and how it’s priced for projects. You’ll also learn about other designs and how pricing is affected by the change in design. And to conclude, we’ve provided a simple home design with common dimensions as an example to help you understand the complete pricing process.

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Designing Wood Trusses to Accommodate Appropriate Spacing

Kansas wood trussesWhen it comes to designing wood trusses, the spacing of each truss according to each design is crucial. If you miscalculate any bit of the spacing and don’t consider the use of the building you’re constructing, then you’re likely to end up with a compromised structure that can present a hazard.

Today, we want to run through a design scenario to discuss how we approach design and our consideration of spacing. If you have any questions along the way, please don’t hesitate to reach out to our team. We’re happy to help – 580-852-3660

Here’s the design scenario:

Take trusses that are spaced 4’ apart. They are loaded for a post frame construction that has purlins on the top cord with metal screwed down to that.

The bottom of the truss is open and exposed from underneath although the building will be completely enclosed. So on this 30’ span truss, it is resting on 5 ½ inches at each end.

On that small surface, there is 1560 lbs. of weight on the bearing point. This is every 4’. So if the trusses were spaced out to 8’, there would be double that amount of weight.

[Read more…]

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Consider Attic Uses When Designing Home Trusses

wood trusses in OklahomaFraming your home with trusses comes with some key advantages. Trusses tend to be cheaper and stronger than traditional framing methods.

But trusses have one more advantage: they’re also perfect for creating functional attics.

The attic is the natural area contained within the trusses and below the roof. When designing trusses, you need to consider future use of your attic space so you can design trusses accordingly.

Top 10 Uses for Attics

An attic is the space between the roof and the ceiling of your house. Many people leave attic space unused. However, the structural part of the roof can be modified in a cost-effective and inexpensive way to add valuable square footage to your home or business in the form of a useable attic area.

Here are some of the most common uses for attics:

[Read more…]

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How Prairie Winds Affect Wood Trusses in Kansas

Storm Clouds SaskatchewanKansas is notorious for its prairie winds. Engineers have always had to take these winds into account when designing structures across the state.

Prairie winds can be downright dangerous if you’re working with the wrong building materials.

Every day, truss designers need to take a variety of factors into account when building for the prairie winds in Kansas. Here are some important things to know about how truss systems are affected by Kansas prairie winds:

Truss builders need to calculate wind pressures using two blended methods

There are two broad ways to calculate wind pressures: Main Wind Force Resisting System (MWFRS) and Components & Cladding (C&C).

MWFRS applies to a structural frame or an assembly of structural elements that work together to transfer wind loads to the ground.

C&C applies to components that directly receive wind loads – like wall coverings, roof coverings, fasteners, and girts. Components and Cladding are typically exposed to higher wind pressures than MWFRS elements.

Trusses fall into both categories. Thus, the industry-standard practice is to design the truss to handle both MWFRS loads and C&C loads.

Truss builders need to consult wind maps to identify correct wind speeds

Building codes typically require the use of a 90-mph wind speed for inland areas of the United States. However, you’ll need to consult local wind maps and government building codes for region-specific information.

Experienced builders don’t settle with just the 90-mph wind speed standard. Experienced builders increase the durability to handle wind speeds around 100 and 110 mph. With wood trusses in Kansas, increases wind speed durability is a major consideration. All trusses must be designed to withstand substantial wind, more than the average structure.

Building usage affects wind pressure calculations

Buildings fall into a number of different usage categories. Specifically, there are three broad categories of building usages:

-Category I: A building that will have a low hazard to human life if it fails

-Category II: A building that presents a substantial hazard to human life if it fails

-Category III and IV: Buildings that are critical facilities or present a substantial hazard to human life in the event of a failure.

Different building exposures affect truss design

Buildings located on empty, flat land are more affected by wind pressure than buildings surrounded by trees and other buildings.

Building codes classify these buildings in four different ways:

Exposure A: Buildings located in downtown areas or city centers.

Exposure B: Urban and suburban buildings that are surrounded by similar-sized buildings and trees.

Exposure C: Buildings in an open area with scattered obstructions.

Exposure D: A building exposed to unobstructed wind for at least one mile over flat land.

Good truss builders take all of these factors into account

Ultimately, truss builders have a lot of responsibility. In Kansas, flat plains let wind travel unobstructed for hundreds of miles. Rural buildings and even many suburban buildings are rarely protected against substantial wind.

To take truss manufacturing to the next level, Timberlake TrussWorks builds wood trusses capable of withstanding strong winds. The key to a sound structure requires the builder to guarantee trusses are fastened tightly against the wall. This is accomplished by installing TimberLOK Screws, which we happily provide.

These screws are hurricane ties – able to withstand the brunt force of harsh winds caused by severe storms. TimberLOK Screws keep trusses and roofs stable and secure during harsh weather conditions experienced on the plains of Kansas.

If you’re shopping for wood trusses in Kansas, then you can’t settle for average. Kansas’s prairie winds chew up average wood trusses and quickly reduce the lifespan of structures. If you’re looking for wood trusses in Kansas that offer a higher level of quality and longer-lasting support, then order from Timberlake TrussWorks today.

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Designing for Truss Deflection in Oklahoma

91370356268-mediumUnderstanding deflection within the design of trusses is one of the most important aspects when considering a truss system.
We spend considerable time determining the deflection, load amount and span of a truss. We review the specs again and again so our customers receive considerable spans, but spans that are deflected safety and effectively.

But first, let’s discuss the basics of deflection of our Oklahoma wood trusses a bit more:

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Preparing Wood Trusses for Oklahoma Wind

Oklahoma is notorious for strong winds at a moments notice. Whether a storm is brewing or it’s a beautiful day, wind is a considerable factor for building and construction experts to consider when developing within the plains of Oklahoma.

Just take a look at the power of wind in the state within the last year:

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