The Science Behind Fence Construction That Lasts

March 31, 2024

Putting up a fence isn't as simple as chucking wood at the ground and connecting the thicker bits with thinner bits. Constructing a fence is a slow-motion arm wrestling match against the force of gravity and decay.

Thekey to solid fence construction is understanding the balance of forces actingon each piece placed. The posts to the slats to the joists all need to work intandem to stay stronger longer.

Enduring FenceConstruction

Nofence lasts forever, but a well-constructed fence will last fifteen or moreyears. What contributes to enduring fence construction? A solid grasp of theforces trying to pull it down.

Fencesface pressures from gravity, corrosion, exposure, and mechanical failure.Keeping a fence standing strong means reducing each of these pressures withbest-practices and industry-leading techniques.

Ourresidential and commercial fences need to function foryears while looking good.

Physics and Fences

Fencingmaterials face a multitude of forces that can be easy to overlook. Wind pushesagainst the slats, a force that must be countered by the posts. Posts need toanchor the fenceline against this pressure and also mitigate temperaturevariations.

Theupward load-bearing characteristics of a post and the connecting fence need tobe strong enough to resist the weight of the materials. The more space betweenposts, the stronger the material needed to avoid sagging over time. 

Forfulcrums, such as gates, additional reinforcement to counterbalance the outsidepull is important to avoid sag and mechanical wear on hinges. 

Thetensile strength of slats, chainlink, or other material needs to be adequate toavoid sheering when impacted. For areas with high levels of morning dew, thefence also needs to evenly distribute weight across the entirety to avoidsinking in softer soil. 

Thefollowing breaks down the forces that bear on each component of the fence andhow proper construction mitigates each issue.

Posts

Theseating of posts is incredibly important to provide them with adequatereinforcement. 

Fenceposts need to be deep enough to offset the lateral force of winds, theoccasional contact, and creatures (human and other) that sit on top or climbover the fence. A commercial fence may also need to support the weight ofcameras and additional security features.

Thedepth a post is planted matters based on the frostdepth of the area. Deeper frost allows for deeper posts. When a postencounters the frost line it will heat unevenly between the top and thebottom which can warp wood and create strain. Metal posts generate heat morequickly and suffer a larger flux across the length.

Postsare seated on a gravel base to provide drainage of the water coming in frombelow ground. Setting them in concrete or gravel backfill gives them some roomto absorb vibrations and also offers friction to grip the ground.

Finally,a sloped area near the visible base wicks water away from the seating and awayfrom the fence in general. 

Postmaterial is a hotly contested subject in fencing circles. Steel posts offerlongevity in some areas but wooden posts withstand damage better and, in the rightconditions, weather more slowly. 

Slats

Thematerial for slats is less contested. Generally speaking, the choice lasts aslong as repairs are made and weathering doesn't change.

Slatsface the forces of wind, sun, and weathering. Fasteners need to hold fastwithout creating pinch points that lead to cracking or shattering in highwind. 

Chainlink allows wind to pass through, lowering the overall tensile forces on posts.Chain link features a 30-year lifecycle and is easy to repair or replace in theeven to damage. That said, chain link is also the least visually appealingfencing material.

Brickor masonry fences last even longer (50ish years) but also weigh considerablymore. They need to be maintained more regularly to remove corrosive elementsfrom the mortar. They also need reinforcement along the ground line in areasother than just the posts.

Vinylfencing is a popular option that looks great and lasts a long time (40 years).Vinyl is cheaper than wood and looks great for residential and commercialapplications. The sound dampening of vinyl and wood fences are great featuresfor a busy neighborhood. 

Vinylslats offer components that are quick to replace but can't be repaired orpatched. Vinyl also resists corrosion and water better than any othermaterial. 

Woodfencing falls into the most expensive category because of its initial cost andshorter lifespan. Treated wood that is well-maintained will last 15-20 yearsbut eventually weathers away.

Woodslats take and hold paint and stains well and are easy to maintain and replacepiecemeal. Higher-end woods provide unparalleled beauty with their rich colorsand grains.

Weathering

Thetwo biggest forces contributing to the weathering of fencing material are waterand corrosion. You don't need to live in an area with heavy pollution forcorrosion to be an issue. Debris from roads and residue from exhaust settle ona fence over time.

Thisis why it's worthwhile to have a yearly maintenance schedule to pressure washor repaint a fence. Removing corrosion build-up keeps a fence looking fresh andalso prevents years from being melted off the material's lifespan.

Forareas with a lot of moisture, fences need to get enoughsun to dry thoroughly or need to be seated in ways that allow for properdrainage and runoff. 

Groundcoverplants, and especially vines or creepers, need to be watched and trimmed toavoid roots pushing up areas of the fence. Weathering is the main culprit offence decay but plant growth can lead to buckling if the area isn't clearedbefore installation. 

Build Right

Whetheryou are looking for a security fence for a business or a privacy fence for ahome, you want lasting quality. When all of the elements offence construction are considered, the resulting fence will stand strong.

Wedeal in both commercial and residential fences. Contact us for an estimateand availability.