Creating a durable post-frame building is all in the details – no matter how small. In fact, sometimes it’s the smallest construction techniques that make the biggest difference. Here are 13 to keep in mind for your next post-frame construction project.
The key to incorporating these techniques into post-frame construction comes down to your project engineer and design team. Actually, very few follow each of these guidelines – and as a result durability suffers.
Stay educated and be persistent. Your project team should follows these techniques in their post-frame construction:
2. Create a 4’ overlap on spliced columns – Any column over 20’ in length should utilize a 4’ splice overlap pattern (with truss plates on the exterior of columns) in addition to 4.5” spiral nails and joint reinforcement truss plates. This creates a splice that is 50% stronger than typical nailed splices.
3. Ensure your in-ground columns have a minimum depth of 4 feet – For the strongest foundation to fight the elements that mother nature throws your way.
4. Use uplift anchors on columns – Uplift anchors are extra pieces of treated wood at the bottom of the column that acts like an anchor, preventing the columns from being lifted by wind. Unless you fill the foundation holes with concrete, these anchors create a much stronger foundation. Otherwise, when strong winds blow, they can actually lift a side of the building and drop it back down, possibly toppling or compromising the structure.
5. Include temporary wind bracing during construction – Your post-frame building project likely won’t be completed in a single day. There will be periods when it’s incomplete, making it vulnerable to what’s called “racking”, when wind blows and misaligns the materials.
By installing temporary – and ultimately permanent – wind bracing, you can ensure that the building has the rigidity it needs to remain in alignment before construction completes.
6. Apply permanent wind and corner bracing – Include wind bracing in the final construction to protect it from high winds. This is especially important for tall and large-span buildings.
7. Lay out the building envelope before construction starts – The best way to make sure your building is square when finished is to measure and mark the diagonals. Diagonals are the measurements from opposite corners of the building. The corners should be exactly the same distance apart, or diagonal measurements should exactly the same. That way when your building columns are set or the concrete is poured, the building walls will be straight and square.
8. Use Machine Stress-Rated lumber for all structural components – There are two types of lumber grades: Machine Stress-Rated (MSR) – whose strength is tested by a machine – and Visual Grade, which is based on certain visual inspections.
While Visual Grade lumber has been the industry standard for years, its quality has deteriorated over the past 10 to 20 years due to the rise in fast-grown tree farms. In fact, the National Lumber Grading Association has determined that the design strength of visually graded #1 SYP lumber is 25% weaker than its historically rated value.
That’s why we recommend using MSR lumber for every component of your post-frame design. This lumber runs through a machine that tests the strength of each board using either a mechanical bending process or a process similar to an ultrasound that tests wood density and structure.
That way, you can be absolutely certain of your building’s minimum strength, and how it will fare in the face of extreme weather.
9. Use screws instead of nails for exterior steel attachment – Nails essentially displace the wood fibers when hammered in – but those fibers push back, forcing them out over time.
Screws, on the other hand, pull the fibers upwards towards their head as you tighten them. Scientific testing has shown that this gives screws about twice the fastening power of nails.
10. Ensure labor uses high lifts on tall buildings wherever conditions allow– Balancing on a ladder high up in the air can be difficult when a builder is trying to complete a task. A screw, for instance, might not go in straight or sturdy. This can affect the overall quality of a building.
Using a scissors lift – which raises a builder from the ground on a stable platform – help ensure they’re in optimal conditions to complete their work.
11. Engineering drawings should provide exact cut lengths – Cut lengths tell the builders the exact angle and length to cut a board so they don’t need to cobble materials together. Otherwise, if a piece doesn’t fit correctly, a builder may just jam it in place, impacting the structure’s durability.
12. Use Quik Drive tools – Using the right Quik Drive tools increases efficiency and accuracy of a build. Once the tool gets properly adjusted, it will achieve the optimal screw depth for every screw.
13. Use Ring shank nails for attaching dimensional lumber – Ring shank nails have rings embedded into them, so the rings catch the wood fibers in the divots. These nails are much harder to pull out of wood than a straight nail, making them tougher for wind to pull apart.
Small design qualities make a big impact on the durability of post-frame buildings. Be sure your project engineer and design team incorporate these 13 techniques, so you can feel secure that your building lives a long and sturdy life.