Tag Archives: vegetation

Wind Exposure and Confusion

If you are a registered design professional, or a building official, then you are trying to make sense out of this subject on a daily basis. Most people who are selling buildings (either constructed or kit packages), tend to ignore wind exposure, or pretend it somehow doesn’t exist.
What adds into confusion, for all involved, is (even though written by same group of experts) IBC and IRC definitions do not exactly align!

Choosing a proper wind exposure is crucial to your building’s proper structural performance. Exposure C buildings must withstand a roughly 20% greater wind force than Exposure B and Exposure D, yet another 20%! This can result in one or more of deeper and/or wider column embedments, more concrete required to prevent uplift, larger columns and/or more closely
spaced, larger dimension and/or higher grades for wall girts and roof purlins, changes in truss design (larger and/or higher graded chord lumber, more webs, larger steel connector plates), ‘beefier’ connections, etc. In a nut-shell, it can change nearly every structural member and connection. To ignore proper wind exposure can result in catastrophic failures.
For utter confusion’s sake, I’ll list 2021 code sections (just in case you need some “put me to sleep” late night reading material.)
(HINT: At end, I include a broad generalization providing a close idea for most building sites.)
Picture entering a code book resembling a surrealistic painting by Salvadore Dali.
IBC Section 1609.4‐‐Exposure Category: “For each wind direction considered, an exposure category that adequately reflects the characteristics of ground surface irregularities shall be determined for the site at which the building or structure is to be constructed. Account shall be taken of variations in ground surface roughness that arise from natural topography and vegetation as well as from constructed features.”
IRC Section R301.2.1.4 Exposure Category: “For each wind direction considered, an exposure category that adequately reflects the characteristics of ground surface irregularities shall be determined for the site at which the building or structure is to be constructed. For a site located in the transition zone between categories, the category resulting in the largest wind forces shall apply. Account shall be taken of variations in ground surface roughness that arise from natural topography and vegetation as well as from constructed features. For a site where multiple detached one- and two-family dwellings, townhouses or other structures are to be constructed as part of a subdivision or master-planned community, or are otherwise designated
as a developed area by the authority having jurisdiction, the exposure category for an individual structure shall be based on the site conditions that will exist at the time when all adjacent structures on the site have been constructed, provided that their construction is expected to begin within year of the start of construction for the structure for which the exposure category is determined. For an given wind direction, the exposure in which a specific building or other structure is sited shall be assessed as being one of the following categories:”

Exposure determination is not relegated to a nice, comfortable chart or table. This section’s main part explains ground roughness variations from natural topography and vegetation need to be take into account when determining Exposure Category.
IBC Section 1609.4.1‐‐Wind Directions and Sectors “For each selected wind direction at which the wind loads are to be evaluated, the exposure of the building or structure shall be determined for the two upwind sectors extending 45 degrees either side of the selected wind direction. The exposures in these two sectors shall be determined in accordance with Sections 1609.4.2 and 1609.4.3 and the exposure resulting in the highest wind loads shall be used to represent wind loads from that direction.”
Here we get started in determining Exposure Category, but this process is three‐step from here.
Breaking this babble down to something making sense isn’t easy, but a list helps:
1) Select wind direction for wind loads to be evaluated
2) Two upwind sectors extending 45° from either chosen wind direction side are markers.
3) Use IBC Section 1609.4.2 and Section 1609.4.3 to determine exposure in those sectors
4) Exposure with highest wind loads is chosen for this wind direction
Got all this? If not, you aren’t the only one. But wait, there’s more! Tune in next time for yet
another fascinating installment!

Where Should You Place Your Pole Building?

Where Should You Place Your Pole Building?

Today’s guest blog comes from an expert in pole buildings, Lauren Groff.

Pole buildings are perfect for so many applications, from sheltering animals to housing your very own hobby shop. Whatever you want to use it for, you need just the right place for it. There’s more to picking a spot for your building than you’d think, though. Here’s some things you need to consider when planning your construction project. 

Zoning Considerations

This is the very first thing you need to consider when planning a pole building. ‘Once you have plans, you’ll need to submit them for inspection’ says writer Bill Thompson. ‘The authorities will be looking to see that your building will be located in a safe position.’

This includes keeping the building away from any power lines, and existing roadways. There will usually be size restrictions as well. Get acquainted with these rules before you start planning, so the zoning inspection goes smoothly.  

Access To The Building

There’s so many things to consider here. Firstly, think about where you’ll access your pole building once it’s completed. If it’s far away from other buildings on the property, are you going to put in an extended driveway? Will there be walkways? If you don’t want to do any of those things, you’ll need to move the plans closer to existing buildings. 

Remember the construction crew will need access to the site while they’re building too. Can they get in easily? Is there anything they will need to work around, such as vegetation you want to preserve?

Also, keep utilities in mind. You’ll want to hook up electricity, water and possibly gas or internet to your building. Is that easily done in the spot you’ve chosen?

Weather Patterns

Your local weather patterns will affect how you place your pole building. For example, if you see a lot of rainfall, then you should place it on a slightly higher elevation. This keeps it dry as it will allow for better drainage. 

If you want to take advantage of sunlight to warm a building, then you’ll want windows facing the southeast. This will allow the sun in, so you can take advantage of all the free warmth. You can also use the sun to melt snow on the side of the building you’ll access most, making it easier to get in and out. 

Lay Of The Land

Smoky MountainsAre you looking to build on sloped land? It certainly is possible, and you can even gain benefits from doing so. You will need to plan around that land though, to ensure your pole building is positioned correctly. 

Firstly, remember that the construction crew will need to be able to gain access to the land to start building. If the land is too steep and difficult to traverse, you may want to pick another spot. 

Secondly, remember that slopes will affect drainage. It’s usually best to build on top of a slope, as this will allow water to drain away from the building. If it’s at the bottom, you run the risk of water running into the building itself. 


Think about how you’ll landscape around the building once it’s installed. ‘The right vegetation can offer shade in the summer, as well as a natural windbreak when needed’ says building expert Carrie Anderson. ‘if you don’t already have it in the area, look into planting the right vegetation to get the results you want.’

Of course, the right plants will not only give practical benefits, but improve the look of the outdoor area too. Consider how you want to landscape the area before you start building. 

Available Views

Finally, what kind of views will your pole building have? You may have natural areas nearby, such as lakes or mountains, that are areas of natural beauty. If so, you should take advantage of them. Try to place your building where it can get the best view of those areas. 

With these tips you’ll be able to find just the right placement for your pole building. Keep practicalities in mind, as well as the existing land and vegetation. You’ll be sure to find just the right spot and get the most from your pole building. 

Lauren Groff is a manager and writer for Book Report Writing and Big Assignments. She’s an expert in pole buildings, and shares her knowledge through informational articles. You’ll also find her blogs at Best Essay Services.