If you’re installing some fence posts in concrete, then one of the first questions that typically pops up is “What is the best concrete mix for fence posts?” This is a good question, as there are many options when it comes to concrete mixes, so nailing it down to a single best one can be a little tricky.
While there are plenty of solid contenders, for my money the best concrete mix for fence posts is Quikrete’s fast-setting mix. It ticks all the boxes when it comes to a concrete mix for setting fence posts: it’s easy to use, readily available, is designed to dry and cure at a much faster speed than typical concrete, and can be used without pre-mixing the concrete.
Let’s take a look at some of the other top choices for the best concrete mix for fence posts, and how to pick the ideal one for your fence installation.
Quikrete Fast Setting Mix
The best overall concrete mix for fence posts in my opinion is Quikrete’s fast-setting mix. I’ve used this stuff extensively for setting fence posts in concrete and is the ideal solution when you want to quickly and easily set fence posts and move on to installing the rest of the fence.
This fast-setting mix is ideal for fence posts, mailbox posts, lamp posts, and decks, and can also work well for small slabs, sidewalks, and steps. The mix comes in 50 lbs. bags instead of 80 lbs. bags, which makes transporting and pouring the dry mixture more convenient than with traditional concrete mixes.
Unlike traditional concrete mix, Quikrete does not need to be pre-mixed before application. You simply dig your post hole, place the fence post inside it, and then pour the dry mixture directly inside the hole. Then, you add the recommended amount of water and allow the footing to dry and cure on its own.
This makes fast-setting mix the ideal solution for small to medium-sized jobs. You’ll save a ton of time and effort on the mixing as well as significant time savings while waiting for Quikrete to dry.
For comparison, Quikrete’s fast-setting mix takes just 20 to 40 minutes to dry and will cure enough to bear weight after just 4 hours. Typical ready-mix concrete will take significantly longer to dry, at 24 to 48 hours before it’s dry enough to handle foot traffic.
Quikrete’s fast-setting mix does cost a fair bit more than standard concrete mix, and this can become a factor in larger jobs, where the costs can add up quickly. An 80-pound bag of standard concrete mix will run you about $5, meanwhile, a 50-pound bag of fast-setting Quikrete will run you about $6 – so approximately double the cost for the fast-setting mix.
Sakrete Fast Setting Concrete Mix
The main competition to Quikrete in the fast-setting concrete niche is Sakrete. Sakrete’s fast-setting concrete mix is similar to Quikrete’s mix in nearly every dimension and is designed to fulfill the same basic use case.
Sakrete’s mix is designed for no-mix post setting, so it can be applied directly to a post hole and then filled with water in the same manner as Quikrete’s mix. It will set in just 30 mins, is ready to handle foot traffic in 6 hours, and can handle vehicle traffic in just 48 hours.
Like Quikrete’s fast-setting mix, it comes in 50-pound bags and costs a similar $6 per bag. Both mixes cure to a final compressive strength of 4000 PSI when completely cured, so there’s actually not much separating the two.
My own recommendation goes to Quikrete simply based on having used it for years. I’ve only used Sakrete a couple of times and didn’t notice any major difference or disadvantage, so I wouldn’t hesitate to use it if that’s all that was available.
Standard Concrete Mix
Standard ready-mix concrete is not the typical choice for installing fence posts in concrete, but it can be a good choice when you need to keep costs down and don’t mind waiting slightly longer for your footing to dry/cure.
As mentioned previously, standard concrete mix costs about half of what fast-setting concrete costs. This can be a major factor if you’re building a lot of fencing, or if your budget is tight and need to cut any excess costs.
Keep in mind that if you go this route, you’ll need to pre-mix the concrete before pouring it. That means you’ll need to use the correct amount of water when mixing, as too much water in your concrete mix can weaken it and result in a poor-quality final product.
You don’t need to worry about this too much when you’re using a fast-setting concrete mix, as excess water in a fast-setting mix will simply absorb into the surrounding soil instead of staying inside the mix.
Fast 2K Fence Post Mix and Concrete Alternative
A newer alternative to fast-setting concrete mixes is expanding concrete foam that expands and hardens to lock a fence post in place and prevent it from moving. It’s similar to the compound used by professionals to set utility poles, so you can be sure you work with a tried and true product that will last for many years.
Keep in mind Fast 2K Fence Post Mix is quite different from concrete, so you shouldn’t expect it to perform in the exact same manner. To use the product, simply mix for 30 seconds, break open the packaging, and pour the mixture into your post hole. It’s designed to adhere to wood, vinyl, and metal, and even binds to itself with ease.
Unlike concrete, the fence post mix prevents water from penetrating through the seams of each post, so you’re less likely to get rotten fence posts like you sometimes find with concrete.
The post mixture is also extremely lightweight, so you can essentially replace an 80-100 lb bag of concrete with a single 2 lb bag of expanding composite post mix.
When it comes to picking out the best concrete for fence posts, Quikrete’s fast-setting mix is a safe bet for the top spot. It dries and cures rapidly, allows you to pour the dry mix directly into the post hole, and is designed specifically for use with fence posts.
Standard concrete mix is another decent option, especially when you’re on a tight budget. And if you’re looking for a lightweight alternative to concrete, then expanding foam merits a closer look.