Hey guys i'm James. In this video i'm going to put to the ultimate test a rapid setting concrete
post mix, versus a fence post foam. Now we're going to be using this product called sika pro select
fence post mix. Now it's an expanding foam product and we're going to strength test it
against your standard rapid setting concrete. Let's go ahead and get started. So i've honestly
never used this product before, i've seen a lot of videos on youtube, it's quite big in America and
they seem to say that it's quite good. I've already got my opinion about it before we've even started.
I've not been paid to review this product so i'll be giving you my honest opinion of it at
the end of the video, so stick around. Okay so what we have here is two four by four posts, four inch by
four inch. They're seven foot high, two foot in the ground, so we've got five foot sticking up
above ground level. Now on the packet it says it's equal in volume to two fifty pound bags
of concrete mix, so that's gonna be the equivalent of two 20 kilogram bags of post mix.
What it also says on the packet is if there's any standing water in the bottom of the post hole
you need to get rid of that first before you use it. Now if you're putting fence posts up in the uk
that's probably not a good thing because if you have to do any fencing in the winter you're going
to be siphoning out a lot of these fence post holes and if you've ever had to do that before you
know that's a messy business. Okay so for the left hand post we're going to be using the concrete
and as it says on the bag it's the equivalent of two bags of post mix, so that's what we're
going to be using. For those of you that don't know you first fill up the hole with a third of water,
add your post mix and then you top up with a bit more water at the end and that's just to cover
any dry powder that's showing. Now this is the fun bit. I'm genuinely interested to see how this stuff
performs but essentially it's a two-part mix and you need to break the seal down the center
and mix it for 15 seconds. Once mixed you cut the corner off and then pour it straight into the hole.
You need to be absolutely ready for this though because once you've mixed it it will just start
to expand and if if you don't open the bag quick enough, or you know you haven't got your post level,
It's just going go all wrong. So let's start by breaking the seal.
There we go.
It's like a black liquid. Make sure it's all squeezed out. I can feel it warming up already,
in the bag. In fact it's getting very hot. So we've got it all out. I dont know if you can see that
but it's already filling up, i'm just wondering how far this is actually gonna get to the
top of this hole. Apparently it sets in three minutes so that's probably a bit quicker than
the rapid setting concrete and then you can use and work off of it within two hours. Like
hang a gate from it, which is probably about as quick as i'd like to work on a
pre-mixed fast setting concrete. Okay so this is what's left of the packet, still had a bit inside.
It's it's gone off inside the packet and see it's just spilling out the end there
but it's been about 10 minutes now and i'm sure that's probably
expanded as much as it will do. It's gone pretty hard now. Okay guys so that's both of the posts
set now, we'll come back in a week's time and then we'll test the strength of both posts.
Okay guys so it's actually only been six days but on the packet it says it sets within two hours and
that's good enough to start hanging a gate off or building your fence, so six days is plenty of time.
The foam hasn't risen level in the hole, it's raised up in places and you've even got these
little voids right next to the post. When water runs down the post, it's going to collect into
those little pockets around the bottom of the post and that will just hold the water and then the
post will rot a lot quicker and then if you come over here chris and have a look at the concrete.
Now if you can see in there it's the concrete's set completely flat. So normally
what would happen is you'd fill the concrete right up to the top of the hole
and you'd smooth the concrete away from the post, so any water that ran down the post
it would just run away from the bottom rather than collect. Okay so now for the ultimate test.
The concrete seems absolutely solid and that's not going anywhere but the foam
is not looking too good. Foam is set completely rock solid
but it doesn't seem to have filled the hole completely. It's obviously expanded
and then contracted inside the hole, which has just left it completely loose.
So i'm not really trying very hard at all and that post is completely wobbly. This is absolutely fine,
it's not going anywhere.
Well that is not very good at all.
ah... it's almost coming out, just doesn't want to come out in that last bit.
Touching that that is soaking wet,
it's completely wet around the post. That is obviously not very good for
if you're putting in a wooden post because that is just going to rot. Have a look down inside the hole.
That really is not going anywhere.
Okay i'll try and do the same as i did with that one and try and pull out my hands.
Oh.. Okay it's loosened off. Okay that one was a bit easier to get out.
It was initially a lot more stable than the foam was. After using both of these,
is i don't really like the foam at all. Um a couple of reasons why. One, you can't manipulate the
foam as it's rising. With the concrete like i said you can sort of smooth it away from the post to
create a runoff for the water. It still didn't really seem to adhere to the post very well and
um it left a void between the foam and the post. Didn't expand correctly, it expanded and contracted
which left the post completely wobbly inside the hole. That would have meant that your fence would
have just been wobbling all over the place if there was any wind at all. Foam doesn't have any
weight to it. One of the main things about concrete and its ability to hold posts in the ground, is the
weight of the product itself. Of course with foam it's as light as a feather so it doesn't have that
effect on the bottom of the post and it's not going to anchor the post into the ground like
concrete will. Thank you guys for watching. I hope you found this as insightful as i have.
I know exactly what products i'm going to be buying to set my fence posts
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