How far apart do vinyl fence posts go?

As far as the manufacturer's wind table allows, which is not one number. Bufftech publishes 97 in for wind exposure B at a 30 in footing, 68 in for exposure C at 30 in, and 56 in for exposure D at 30 in. The standard section is 72 in, so in exposure D at that depth it does not fit.

Can I space vinyl fence posts 8 feet apart?

Only where the wind table permits 96 in, and none of the Bufftech figures reach that: the widest listed is 97 in, for exposure B at a 30 in footing. Eight foot sections exist, so check the maximum for your exposure and footing before buying them.

How deep should vinyl fence posts be?

Bufftech says 30 in deep or to the frost line, whichever is deeper. Frost depth is local. Depth also buys spacing: the wind table gives a wider maximum for a deeper footing.

What size hole for a vinyl fence post?

About 10 in for a 4x4 post and 12 in for a 5x5, per the Bufftech guideline, with the bottom belled and the concrete tamped and finished 2 to 4 in below grade.

Why can't I just cut a vinyl section shorter?

You can shorten rails, but the posts are routed at fixed positions to receive them and the pickets are sized to the section. Cutting is normal at the end of a run and at a corner; it is not a way to change the module.

What is wind exposure B, C and D?

Categories from ASCE 7. Broadly, B is suburban or wooded, C is open terrain with scattered obstructions, and D is flat unobstructed ground, often near open water. Your building department will tell you which applies.

The High Velocity Hurricane Zone, which the Bufftech table defines as Miami-Dade and Broward counties with wind exposures per ASCE 7-10. Those have their own requirements including aluminium post inserts.

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Vinyl Fence Calculator

Post spacing from the Bufftech WindZone table, not a rule of thumb

Everyone says vinyl fence posts go 6 ft apart, because that is the length the sections come in. The manufacturer publishes a maximum that depends on your wind exposure and how deep you dig, and in the worst exposure at a 30 in footing it is 56 in, which a standard 6 ft section does not fit. This checks yours against the table.

Vinyl fence takeoff

Total run

Fence height

Wind exposure

Footing depth

Section width

Post size

Rails per section

no.

End posts

no.

Corner posts

no.

Gate openings

no.

Maximum spacing and footing depths from the Bufftech installation guideline.

Specification summary

Generated from on . Reopen that address to reproduce these figures exactly.

Entered

Result

Post spacing against the wind table maximum

Worked example

A 100 ft run of 6 ft privacy vinyl in suburban exposure B, standard 6 ft sections, 4x4 posts, footings 30 in deep.

The maximum. Exposure B at a 30 in footing allows 97 in between posts. A 72 in section is comfortably inside it.
Now change exposure to D. At the same 30 in footing the maximum drops to 56 in, and the standard section no longer fits.
The fix is depth, not width. Go to a 36 in footing in exposure D and the maximum rises to 75 in, and 72 in fits again.
Sections. 100 ft at 72 in is 17 sections and 18 posts.
Concrete. 18 posts in a 10 in hole 30 in deep is 24.5 cu ft, or 41 sixty pound bags.

That exposure D case is the one worth knowing. It is not exotic, it is any flat open site near water, and the material list is identical right up to the moment it fails inspection.

The formula

Sections divide the run. The maximum spacing is looked up, not derived:

sections = ⌈ 12L / w ⌉ posts = sections + 1 concrete = n π (d/2)² h

L: total run, ft
w: section width, in, fixed by the routing when you buy
n: post count
d, h: hole diameter and depth, in. Bufftech gives 10 in for a 4x4 and 12 in for a 5x5
maximum w: from the WindZone table, by exposure and footing depth

The concrete term uses the full hole depth, which slightly over-buys because the post occupies part of it and the guide fills to 2 to 4 in below grade. Erring high on bagged concrete is the right direction: a post you cannot finish setting is a worse problem than a spare bag.

Why vinyl has a real answer where wood does not

Vinyl fence is manufactured as a system. The rails are extruded to a length and the posts are routed to receive them, so unlike a wood fence you are not free to set the posts where the run works out. The centres are decided in the factory.

That also means the manufacturer has tested the assembly and published what it will stand up to. The Bufftech guideline carries a WindZone table giving a maximum post spacing for each wind exposure at each footing depth, and the spread is large: 97 in in sheltered exposure B at a 30 in footing, down to 56 in in exposure D at the same depth.

The useful part is that the table is a trade rather than a limit. Deeper footings buy wider spacing. In exposure D, going from 30 in to 36 in takes the maximum from 56 in to 75 in, which is the difference between a standard 6 ft section fitting and not fitting.

None of that appears in the guides telling you vinyl posts go 6 ft apart. They are describing what is in the box, not what the manufacturer says you may do with it.

Vinyl post spacing is a wind table, not a number

Ask how far apart vinyl fence posts go and you will be told 6 ft or 8 ft, because that is the length the sections come in. The manufacturer publishes something quite different: a maximum post spacing that depends on your wind exposure and on how deep you dig.

Maximum post spacing by wind exposure and footing depth
Wind exposure	Footing depth	Maximum post spacing
Exposure B	24 in	66 in (5.5 ft)
Exposure B	30 in	97 in (8.1 ft)
Exposure C	30 in	68 in (5.7 ft)
Exposure C	36 in	88 in (7.3 ft)
Exposure D	30 in	56 in (4.7 ft)
Exposure D	36 in	75 in (6.2 ft)

Bufftech Molded and Extruded Fence Installation Guideline, CertainTeed, document e-2201cts

Read down the table. In exposure B a 24 in footing buys you 66 in of spacing; go to 30 in and you may span 97 in. Digging deeper is what lets you set posts further apart, and that trade is invisible in every guide that just says “posts go 6 ft apart”.

Exposure D at a 30 in footing caps out at 56 in, which is under 5 ft. A standard 6 ft section will not legally fit there without a deeper footing. That is the case worth catching before the material is delivered.

HVHZ: Miami-Dade and Broward counties, wind exposures as defined in the ASCE 7-10
Bufftech installation guideline, WindZone table

The standard module itself is fixed by the routing, not chosen:

4 x 4 POST CENTERS 3" PICKET = 72" 1-1/2" PICKET = 72-1/2"
Bufftech installation guideline, traditional picket

Which is the real difference between vinyl and wood. A wood fence lets you set posts wherever the run works out. A vinyl fence is a kit: the rails are cut to length and the posts are routed to receive them, so the post centres are decided before you buy.

Dig holes 30" deep or to frost line. Hole size for 4 x 4 posts = approximately 10". Clean holes and check for straight walls. Bell bottom of holes.
Bufftech installation guideline, digging holes

Note the order of that sentence: 30 in or to frost line. Where frost goes deeper, frost wins, and frost depth is a local number this site will not guess at.

Frequently asked questions

How far apart do vinyl fence posts go?: As far as the manufacturer's wind table allows, which is not one number. Bufftech publishes 97 in for wind exposure B at a 30 in footing, 68 in for exposure C at 30 in, and 56 in for exposure D at 30 in. The standard section is 72 in, so in exposure D at that depth it does not fit.
Can I space vinyl fence posts 8 feet apart?: Only where the wind table permits 96 in, and none of the Bufftech figures reach that: the widest listed is 97 in, for exposure B at a 30 in footing. Eight foot sections exist, so check the maximum for your exposure and footing before buying them.
How deep should vinyl fence posts be?: Bufftech says 30 in deep or to the frost line, whichever is deeper. Frost depth is local. Depth also buys spacing: the wind table gives a wider maximum for a deeper footing.
What size hole for a vinyl fence post?: About 10 in for a 4x4 post and 12 in for a 5x5, per the Bufftech guideline, with the bottom belled and the concrete tamped and finished 2 to 4 in below grade.
Why can't I just cut a vinyl section shorter?: You can shorten rails, but the posts are routed at fixed positions to receive them and the pickets are sized to the section. Cutting is normal at the end of a run and at a corner; it is not a way to change the module.
What is wind exposure B, C and D?: Categories from ASCE 7. Broadly, B is suburban or wooded, C is open terrain with scattered obstructions, and D is flat unobstructed ground, often near open water. Your building department will tell you which applies.
What is HVHZ?: The High Velocity Hurricane Zone, which the Bufftech table defines as Miami-Dade and Broward counties with wind exposures per ASCE 7-10. Those have their own requirements including aluminium post inserts.

Check these numbers yourself

Bufftech Molded and Extruded Fence Installation GuidelineCertainTeed, document e-2201cts. The WindZone maximum post spacing table, hole sizes and concrete figures.
Bufftech and SimTek fencing instructionsActiveYards, revision 4.24. The same product family, a later revision.

How every figure here is verified: Sources & Method. Who builds this: About. Found something wrong? Tell us and it gets fixed or removed.

Figures on this page last checked against the source documents on 2026-09-07. Codes are amended locally; confirm against the edition your jurisdiction enforces.

Related calculators

One manufacturer's table. The wind figures here are Bufftech's and other brands publish their own. Footing depth is 30 in or the frost line, whichever is deeper, and frost depth is local. High Velocity Hurricane Zone installations have additional requirements this page does not cover.