Do Fence Posts Simply Slot In?

Installing any type of fence can be challenging, but there are a few things that make it easier.

Fence posts typically don’t just slot in, but some different types of fence boards can. Concrete, PVCU, and timber posts are most commonly used for boards that slot in. 

Slotting in can mean easier install, but there are a lot more specifics that you need to know before you get too invested.

What is “slotting in”?

When it comes to fences, “slotting in” simply means that the boards or posts slide into place via an existing groove in an opposite post.

Having a fence board slot into the posts definitely has a few benefits to it.

Benefits to a slot fence

The first perk to having the fence boards slot into the posts is ease. When installing a traditional cedar fence, the posts and boards are all wood and all separate.

This means when it’s being installed, all the pieces have to be nailed or glued together in order for the fence to stand.

This isn’t the case with slotted fence boards. The boards are already built and come as one whole piece. The only assembly that is required is the actual slotting in: placing the boards into the posts via the existing groove.

Another benefit to having slotting fence boards is replacement. If one of the sections of boards is falling or sagging it needs to be replaced, obviously.

With a traditional cedar fence, all the nails would need to be removed, or the boards attached to the posts would need to be cut down in order to remove the broken section.

With a slotting fence, it’s so much simpler. The section of fence boards that needs to be replaced can be lifted out of the fence posts, via the existing grooves, and a new section of fence board slots right back into the posts.

Different types of slot fences

There are a few different types of slot fences and they are each very different.

  • Concrete post and gravel board fence
  • PVCU linear (horizontal) fence
  • Split rail fence

Each of these slot fences require different materials, planning, and have pretty different install processes.

Concrete post and gravel board fence

Now, it’s rare to find this type of slot fence in the US due to the simple esthetic of it. With this type, as the name implies, the fence posts are made of a concrete material and the fence boards are made of a material called gravel board.

With this type of slot fence, the concrete posts come with the grooves on each side. There are corner posts, mid posts, and end posts; each with special grooves on differing sides to align correctly with the boards.

Typically, local fence code requires a fence, posts and boards, not exceed 6 feet in height. So, the concrete posts will usually be 8 feet tall so they can sit 2 feet underground.

A good rule of thumb to remember when installing any type of fence posts: place them 6-8 feet apart. With slot fences, though, they should be 6 feet apart for stability.

Because of this fence code and the distance between each concrete post, the gravel fence boards should measure 6 feet tall and 6 feet wide.

The concrete posts don’t need to be set in the ground with more concrete, just the dirt from the hole that was dug. Once the posts are set, the boards can be slotted into the grooves, and voila! The concrete post and gravel board fence is complete!

PVCU linear fence

A PVCU horizontal fence has a similar concept as the concrete post and gravel board fence in that the boards “slot” into the existing grooves in the posts.

However, the posts are usually made from either steel for longevity or PVCU material. Again, these posts will come with the slots already cut.

When installing the posts, they should be set in concrete just to ensure stability. It’s not required, but it is recommended.

The PVCU boards don’t come as one whole section but come as 6 feet (to align with the posts) by 2 feet sections.

So, when installing the boards, 3 PVCU boards are required for one section. These 3 boards are then slotted on top of one another to complete one section of the fence.

This type of fence requires a bit more material than the gravel boards, just because the PVCU boards don’t come completely assembled, but it does make it a bit simpler to replace the board sections is one break; you simply just replace one of the 3, 2-foot boards, rather than the whole board section.

Split rail fence

Split rail fencing still follows the same concept of slot fencing, but instead of slotting the fence boards vertically, they’re slotted horizontally.

This type of fence is usually made from cedar. It’s also not meant for privacy or consistent use and maintenance.

Split rail fences can stand 6-8 feet apart still. The elements don’t affect this type of fence as much, since the wind just passes through the rails.

Since these fences are mostly DIY, there’s a lot of customization involved: height, length, and a number of rails between each post. Once the specific measurements are decided, the slots in the posts need to be cut.

Because of the specific style of this fence, the slots shouldn’t run the whole length of the post, they just need to match where the rails will sit. That being said, the slots need to be big enough for 2 rails, one on each side of the post, to fit through.

Just like the concrete post and gravel board fence, the split rail fence posts don’t need to be set in concrete, just use the dirt from the holes that were dug.

After the posts are set, the rails can be slotted in. Again, the rails are slotted horizontally, not vertically. 2 rails will slide through one slot, with one rail on each side.

Split fences are easily repaired, as well, just in a different sense. This type of fence does require a bit more planning and assembling than the other two listed above, but what’s required isn’t nearly as extensive as a traditional cedar picket fence.

The components of a split rail fence can be disassembled and replaced easily, making for an easy repair process!

Installing slotting fence boards: tips and tricks

There are a few things that make installing any slot fence a bit easier:

  • Avoid installation on a windy day
  • Many hands make light work (especially when installing gravel board panels)
  • Line the slots and crevices with candle wax (any old candle will do) so the boards slide in a bit easier
  • Make sure all measurements and decisions are made BEFORE installation starts

Luckily, slot fences don’t require a lot of planning. But, as always, the more prepared you are, the easier the process will be. Happy fencing!

Fence Frenzy

We at Fence Frenzy absolutely love taking on the challenge of building, or even restoring, a fence. Especially elaborate and exotic fence designs that really make us scratch our heads! We're happy to share everything we've learned with you.

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