How to measure your Post and Post Caps

Measure Post Caps

How to Measure your Post and Post Caps


Finding the measurement of your post and post caps to complement your deck or railing may be a challenging and time-consuming endeavor.

Identifying the ideal post cap for your needs

Post caps come in various shapes, sizes, and alternatives, it is crucial to understand which style will serve your intended purpose most effectively. Having stated all of this, it is of the utmost importance to be knowledgeable about the procedure of estimating your posts. 


If you have this information, you can avoid purchasing a post cap of the incorrect size or kind. But don't be concerned about it. We will see that you have nothing to worry about at any stage of the procedure!

Post & Post Caps

A guide to comprehending and assessing your post cap

You must have an arrangement of the measurement procedure before selecting the post cap that will work flawlessly with your post. The caps sizes we provide have been marked as compatible with the corresponding post sizes. 


Because of this, the measurements of each cap will not be an exact representation of its actual size. It should be possible to grab and hold itself onto the top of the post and fit just tightly enough to prevent corrosion from occurring beneath it. 


When selecting which cap is best for your intended use, it is vital first to understand that there are two primary sorts of hats: internal and external. Specifically, it is crucial to realize that there is an inner cap and an outer cap. 

Post & Post Caps

Internal caps feature ridges that extend from the bottom so that they may fit snugly within the top of your post, whereas external caps extend beyond the sides of the post and hold the outer edges of your post. 


Internal caps are the more common type of cap. When comparing the two kinds of caps, the essential details to keep in mind are the kind of posts you will be utilizing the caps with and the method by which you will measure the two distinct types of caps. 


When determining the circumference of an exterior cap, you should measure it from the inner wall to the internal wall of the opposite side. When choosing the size of an internal cap, you should measure from the ridge's outer edge on the bottom side to the ridge's outer edge on the parallel side.

Post & Post Caps

How to determine the size of your external post cap?

When measuring exterior post caps, start at one inner wall and work your way to the inner wall of the parallel side. 


Because of this, external post caps are designed to be installed so that they sit directly on top of your post and fit just snugly enough so that they prevent corrosion by preventing water from penetrating the surface of the bar and also allow the cap to grip and hold itself onto the post without the use of any screws or adhesive. 


The reason for this design is that the lid can prevent corrosion by stopping water from penetrating the surface of the post. If you have a look at the diagrams that are provided below, you will be capable of noticing the size disparities that exist between the cap size and the actual dimensions. 

Post & Post Caps

It is common for an exterior post cap to give the impression of being considerably more significant than its actual size. This is because the caps will generally have a smaller diameter at the bottom (see the diagram on the right), which corresponds to the post size it is designed to use. 


The procedure of measuring the exterior post caps is a relatively straightforward one. It effectively measures from the inner edge of one of the post cap's walls to the inner edge of the opposing side, and it must consistently match the size of the matching post.

Post & Post Caps

How to determine the size of your internal post cap

As opposed to the ease of measuring exterior post caps, measuring internal post caps might be more challenging. When determining the size of the inner post cap, it is crucial to keep in mind that this particular type of cap will have ridges on the bottom that will slide down and lock into your post. 

Post & Post Caps

As a result, the cap itself will seem more significant than the post size that it is intended to be used with. Before deciding which internal post cap will work with your post, it is essential to calculate the wall thickness of your post.


To determine the size of your internal post cap, follow the same steps as those outlined for determining the size of an external post cap. However, with these, you will need to take your measurement from the outside of one of the bottom ridges across to the outer ridge on the opposite side. 


If you take the time to conduct these measures correctly, they will provide the information you need to link the cap with the corresponding post size appropriately.

Post & Post Caps

How to determine and understand the size of your posts?

Whether or whether you have wooden posts, it is imperative that you first determine the size of the post cap that is required for your needs. 


If you need clarification about the size of your posts, we will walk you through the process of measuring your posts to establish the correct post cap you require. However, a few factors must be acknowledged before measuring anything.

Post & Post Caps

Wooden posts

Before discussing and measuring wooden posts, you must understand the distinctions between the "Nominal" and "Actual" sizes. The identification system that is used in the timber business includes phrases like "4x4" and "6x6." 


However, if you need to learn the difference between Actual and Nominal dimensions, these measures need to be clarified. The terms that are used in the timber industry are known as nominal dimensions. 

Post & Post Caps

These would be the dimensions for a 4x4 and a 6x6 grid. However, actual dimensions are the measurements that are taken of the posts in their most accurate form. Therefore, according to the specifications, a 4x4 will only measure 3-1/2 inches by 3-1/2 inches, and a 6x6 will only count 5-1/2 inches by 5-1/2 inches. 


This is because nominally measured wood specifies the dimensions of the green boards that still need to be finished. However, hardwood boards experience a large amount of shrinkage throughout the drying process.

Post & Post Caps

On top of that, once the wood has been dried and shrunk, it is planned and shrunk still more so that the surfaces are smoothed down, and the post is made to be a single, constant size. The lumber is called "finished" if this stage has been completed successfully. This is where most people need clarification about the situation. 


When determining the size of your post, a helpful rule of thumb to bear in mind is that the actual measures should be utilized wherever the sign for an inch, which is ", is present. In that case, the values of the standards would be regarded as Nominal.

Post & Post Caps

Frequently Asked Questions

What exactly is the function of the post cap?

Said, fence post caps are a cover that you attach to the top of your fence posts to provide a beautiful and protective element to your fencing. 


They are suggested in various designs, hues, and finishes, all of which may be selected to go with the aesthetic of your fence (and garden too).

Why do they cover the tops of the fence posts with metal caps?

The tops of fence posts are also more vulnerable to the drying effects of the sun and wind, which can result in cracks in the wood. 


Fence post caps answer those issues since they shield the post tops from the weather. Your postings will not only have a considerably longer lifespan, but they will also be safer.

Post & Post Caps

What measurement of post cap do I need to purchase?

The optimal size for the aperture in the post used for a deck or fence is between 1/16 and 1/8 of an inch, more significant than the width of the bar itself. 


Because of this, the post cap will be able to rest securely on top of your post without being able to be blown off by the wind.

How can you ensure that the base of a post is safeguarded?

The first three inches of space should be occupied with gravel to prevent the end of the post from touching the soil. 


Gravel expedites the process of water draining away from the base and into the ground below it. Take care to position the seat to be centered within the hole. In the final step, cement should fill the whole gap up to the top.

What is the required space between each post?

Depending on the type of fence used, the typical distance between fence posts is from 8 to 25 feet. To construct a traditional wooden fence, seats must be spaced at a distance of 8 feet, but a high-tensile wire fence may span 25 feet.


Post & Post Caps

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You must have an arrangement of the measurement procedure before selecting the post cap that will work flawlessly with your post.