Calculate Wall Bracing - Part 2- Determine Wind Pressure

Summary

In this educational video, the host delves into calculating wind pressure for wall bracing in building construction. Focusing on different wind directions, the video explains the use of tables 8.1 to 8.5 to determine lateral wind pressure, essential for structural integrity. The host provides a step-by-step guide on selecting the correct table based on roof pitch and building dimensions, ultimately calculating pressures for both the long and short sides of a building. Viewers are encouraged to subscribe for more informative content.

Takeaways

• 🏗️ This video is part two of a series on wall bracing, focusing on calculating wind pressure for different wind directions.
• 📚 The racking force of a building is determined using the method outlined in paragraph 8.3.4, or an alternative method in appendix F.
• 🔍 The alternative method is a simplified procedure that provides a more conservative (safer) solution, requiring more bracing.
• 💡 The video opts for a more economical approach by not using the alternative method, aiming for a balance between safety and cost.
• 📏 The total racking force for each story or level is calculated by multiplying the projected area of the building's elevation by the lateral wind pressure.
• 🌐 Calculations are performed for both the long and short sides of the building, considering two wind directions.
• 📊 The formula for calculating wind pressure is given in kilonewtons, where total racking force equals the area of elevation (in square meters) times the lateral wind pressure (in kiloPascals).
• 📚 Tables 8.1 to 8.5 are used to determine the lateral wind pressure, with specific tables applicable for different building configurations and roof pitches.
• 🏡 For the example building in the video, Table 8.2 is used for the long side and Table 8.4 for the short side, based on the building's dimensions and roof pitch.
• 📏 The building used in the example has a pitch of 30 degrees, is 14.840m long, and 7.270m wide.
• 💨 The lateral wind pressure for the long side of the building is calculated to be 1.1 kPa, and for the short side, it is 1.2 kPa.

Q & A

What is the main topic of the video?

The main topic of the video is calculating wind pressure for wall bracing in building construction, specifically for different wind directions.

Why is the alternative method in Appendix F mentioned in the video?

The alternative method in Appendix F is mentioned because it provides a simplified and more conservative solution for determining racking force, requiring more bracing.

What is the formula used to calculate the total racking force?

The formula to calculate the total racking force is the area of elevation in square meters multiplied by the lateral wind pressure in kiloPascals.

How many wind directions are considered in the calculation?

Two wind directions are considered: one acting on the long side and one on the short side of the building.

What tables are used to determine the lateral wind pressure for different building elevations?

Tables 8.1 to 8.5 are used, with specific tables chosen based on the building's story, roof pitch, and whether the calculation is for the long or short side.

Why is it important to choose the correct table for the building's elevation?

Choosing the correct table ensures accurate calculation of the lateral wind pressure, which is crucial for structural safety and compliance with building codes.

What is the lateral wind pressure for a building with a 30-degree pitch and 14.8 meters in length, according to Table 8.2?

The lateral wind pressure for the long side of the building is 1.1 kiloPascals.

How does the building's width affect the selection of the lateral wind pressure value from Table 8.4?

The building's width determines which width category to use in Table 8.4, as the table provides values for different width ranges, and the closest larger value should be selected if the exact width is not available.

What is the lateral wind pressure for the short side of a building with a 30-degree pitch and 7.2 meters in width, according to Table 8.4?

The lateral wind pressure for the short side of the building is 1.2 kiloPascals.

What will be the focus of the next video in the series?

The next video will focus on calculating the area of the building's elevations and then determining the racking force using the previously calculated wind pressures.

How can viewers stay updated with the video series?

Viewers can subscribe to the presenter's YouTube channel or follow them on Facebook to receive updates on more videos in the series.

Outlines

00:00

🏗️ Wind Pressure Calculation for Building Bracing

This paragraph introduces the second part of a series on wall bracing, focusing on calculating wind pressure for different wind directions as per the building code's 8.3.4 clause. The presenter opts for a simplified, more conservative method from Appendix F, which may require additional bracing but ensures safety. The formula for calculating the total racking force is explained, involving the area of elevation and lateral wind pressure, with the latter determined from tables 8.1 to 8.5. The importance of selecting the correct table based on the building's characteristics, such as the pitch of the roof and its dimensions, is emphasized. The example provided uses a building with a 30-degree pitch, 14.840m in length, and 7.270m in width, and demonstrates how to find the lateral wind pressure from the tables for both the long and short sides of the building.

05:00

📝 Next Steps in Calculating Racking Force

The second paragraph outlines the next steps following the determination of wind pressure on the building's elevations. The presenter informs viewers that in the subsequent video, they will calculate the area of the elevations to then determine the racking force. The paragraph concludes with a call to action, encouraging viewers to subscribe to the YouTube channel or follow on Facebook to stay updated with more informative content.

Keywords

💡Buildsum

Buildsum appears to be the name of the series or the channel where this video is featured. It is likely focused on construction or building-related topics, given the context of the script discussing wall bracing and wind pressure.

💡Wall Bracing

Wall bracing refers to structural elements used to strengthen walls against lateral forces, such as wind or seismic activity. In the video, the theme revolves around calculating the necessary bracing based on wind pressure, indicating its importance in ensuring building stability and safety.

💡Wind Pressure

Wind pressure is the force exerted by wind on surfaces, which can affect the structural integrity of buildings. The video script discusses calculating wind pressure in kiloPascals for different building elevations to determine the required racking force.

💡Racking Force

Racking force is the lateral force that can cause a building to rack or deform. The script explains that this force is calculated by multiplying the building's projected area by the lateral wind pressure, and it is essential for designing adequate wall bracing.

💡Projected Area

The projected area of a building's elevation is the area exposed to wind, which is used in calculating wind pressure. In the script, the projected area is multiplied by the lateral wind pressure to find the total racking force.

💡Lateral Wind Pressure

Lateral wind pressure is the component of wind pressure that acts perpendicular to the surface of a building. The script details how to calculate this pressure using tables 8.1 to 8.5, which is crucial for determining the racking force.

💡Appendix F

Appendix F is mentioned as an alternative method for calculating racking force, suggesting a simplified procedure that may result in a more conservative estimate. It is part of the guidelines or standards being referenced in the video.

💡Elevation

In the context of the video, elevation refers to the vertical surfaces of a building that are exposed to wind. The script discusses calculating the wind pressure on these elevations to determine the necessary wall bracing.

💡Pitch of the Roof

The pitch of the roof is the angle of its slope, which affects how wind interacts with the building. The script uses the pitch to select the appropriate table for calculating lateral wind pressure.

💡Long and Short Sides

The script distinguishes between the long and short sides of a building when calculating wind pressure, indicating that different calculations are needed for each orientation due to the varying exposure to wind.

💡Tables 8.1 to 8.5

These tables are part of the guidelines used to determine the lateral wind pressure based on factors like the building's pitch and width. The script specifies which tables to use for different wind directions and building orientations.

Highlights

Introduction to part two of a series on wall bracing.

Explanation of wind pressure calculation for different wind directions.

Reference to paragraph 8.3.4 for racking force determination.

Introduction of the alternative method in Appendix F for a more conservative solution.

Selection of a more economical method for racking force calculation.

Description of the formula for calculating total racking force.

Mention of the need to calculate racking force in both long and short directions of the building.

Explanation of how to work out wind pressure in kilonewtons.

Identification of the relevant tables (8.1 to 8.5) for determining wind pressure.

Guidance on selecting the appropriate table based on the building's characteristics.

Details on using Table 8.2 for calculating wind pressure on the long side of the building.

Use of Table 8.4 for calculating wind pressure on the short side of the building.

Importance of knowing the pitch of the roof and the dimensions of the building.

Example calculation using a building with a 30-degree pitch and specific dimensions.

Results of lateral wind pressure calculation for the long side of the building.

Results of lateral wind pressure calculation for the short side of the building.

Upcoming steps to calculate the area of elevations and track force.

Invitation to subscribe to the YouTube channel and follow on Facebook for more content.

Transcripts

G'day and welcome back to Buildsum and in this video which is part two of the

series on wall bracing we're going to work out the wind pressure for both our

wind directions okay so paragraph 8.3.4

racking force says that the racking force of a building shall be

determined by using the method outline but in this clause all by using the

alternative method in appendix F now the alternative method is a simplified

procedure and it's going to give you a more conservative or safer solution so

it's going to require more bracing so we're going to go with the the more

economical type which would be this one here so the total racking force for each

story or level of the building shall be the product of the projected area of

elevation of the building multiplied multiplied by the lateral wind pressure

determined from Table 8.1 to 8.5 the total racking

force shall be calculated in both directions

long and short sides of the building so that's why we do two wind directions one

on the long side one on the short side okay so the formula to work out wind

pressure is done in kilonewtons and the formula is the total racking force

equals the area of elevation in square metres times by the lateral wind

pressure in kiloPascals which is what we're going to work out now I'll show

you how to look that up okay so it said there's four tables or five tables the

table 8.1 is for single story or upper story or the upper of

two-story buildings lower story and subfloor of a single story or two story

all vertical surfaces gable ends ski and ends flat wall surfaces so if your

buildings got a flat gable or a skillion you would use 8.1

8.2 is a single storey or up a storey of a two-story building the long length of

the building with with a hip or gable end which is going to be applicable for

us for our long side of the building 8.3 the lower storey or subfloor of a single

single storey or two storey okay so this is for the bottom floor on a two-storey

house long length for the building so it's not going to apply to us

8.4 a single story or upper story of a two-story building short end

of the building so this is again I'll apply to us that we're going to use

8.4 and 8.5 again is for the short end of the

building on the lower storey of a two-storey house so you have to make sure

you pick the right table for the building that you're actually going to

be working this out on so we're going to use 8.2 for our long side and 8.4

our short side so this is the table basically okay so you need a little bit

of information, you need to know what your pitch of your roof is and you

need to know how wide or how long your building is okay so this is Table 8.2

which is we're going to call wind direction one and this is acting on

the long side of the building all right remembering that our building the

building that I'm using for this series it had a pitch of 30 degrees

it was 14.840m long and 7.270m

wide okay so this is the example so if we look at the column four

thirty degrees and then course we're looking at the long side of the building

and our buildings 14.8 we're gonna have to use 15.0 so we

end up with a wind pressure or lateral wind pressure for this building of 1.1

acting on the long side of the building alright so we'll write that down somewhere

so 1.1 and then we'll look at the short side so the short side we're

using 8.4 this will be our wind direction 2 short side the building

similar table just different figures again 30 degree building so we're going

to use the 30 degree column and our buildings only 7.2 wide so we'll have to

use 8 can't go under so we use 8 as they're building widths and we get a

lateral wind pressure on the short side of 1.2 ok so we can write those down

wind prep direction 1 we're going to get a lateral wind pressure of 1.1 m kPa and

wind direction 2 we get a lateral wind pressure of 1.2 kPa okay so now we know

what pressure the wind is going to put on those elevations we can in the next

video we'll work out the area of those elevations and then we can calculate our

tracking force today I'm back just let you know that if you like this video you

can subscribe to my youtube channel or you can follow me on Facebook so you

don't miss out on more great videos