Expanding foam for fence post fixing

[Mercenary Keyboard Warrior]

This was new to me. I stumbled across a you tube video when looking at log cabin flooring (no idea how they decided that was relevant).
The video was US based and was a mix in the bag type product, I thought you know what thats actually not a bad idea, wonder why no one in the UK has thought about it.
But it seems they have!

It looks pretty much the same stuff, just based in a bottle rather than a bag as they US version.

I wonder how strong this actually is. It seems a wonderful idea, and as we know fences normally fail due to rotting around ground level where the you should never allow to mix wood/water/air combination is allowed to run rampant!

https://www.newventureproducts.co.u...F7R5A2avhFD_-2gSoi5Xx4Sy2lfb9_IxoCCQkQAvD_BwE

 

[Buffman]

I've never put in a fence but need to do some soon... Would be interested in this but does it require a bottle for every single post? Imagine the main issue then is cost?

Is there not easy ready mix concrete which is cheaper?

 

[Armageus]

I've never put in a fence but need to do some soon... Would be interested in this but does it require a bottle for every single post? Imagine the main issue then is cost?

Is there not easy ready mix concrete which is cheaper?

Yes you would need 1 bottle per post, but with traditional postcrete/postfix you also need 1 bag per post:
https://www.wickes.co.uk/Blue-Circle-Ready-To-Use-Postcrete---20kg/p/221100

With bulk discount of postcrete, you are looking at nearly half the cost.



Issue I have with it, is that it doesn't look like the post is actually that secure in their video:
https://vimeo.com/261160707

My fence posts that I used postfix on, have absolutely no movement, where that video they seem to have some wobble.

 

[Steampunk]

If this is an expanding foam, I'd check that it's UV stable, as most are not. Foams are also not that strong and can be cut with a knife (no surprise as they tend to be full of bubbles of air or gas). It's also not going to be very heavy, so you won't get a weighted post held in the ground.

Seems like a bit of a faff when postcrete is pretty easy to use, costs less and gives a better result.

 

[Glaucus]

I wonder how strong this actually is. It seems a wonderful idea, and as we know fences normally fail due to rotting around ground level where the you should never allow to mix wood/water/air combination is allowed to run rampant!

this issue is not solved, as seen the foam ends just below ground and he covers the bottom of the post with a thin layer of mud.
I also doubt it is strong, there's hardly any of it there and will be much lighter than postcrete.

If this is an expanding foam, I'd check that it's UV stable, as most are not. Foams are also not that strong and can be cut with a knife (no surprise as they tend to be full of bubbles of air or gas). It's also not going to be very heavy, so you won't get a weighted post held in the ground.

Seems like a bit of a faff when postcrete is pretty easy to use, costs less and gives a better result.

air is not why foams are weak and able to cut with a knife, it's the material used to create the foam. You have foam concrete which obviously has air bubbles good luck cutting that with a knife, there is no reason foams are inherently weak. In fact there are some insanely mindboggling strong foam structures

 

[Mercenary Keyboard Warrior]

this issue is not solved, as seen the foam ends just below ground and he covers the bottom of the post with a thin layer of mud.
I also doubt it is strong, there's hardly any of it there and will be much lighter than postcrete.



air is not why foams are weak and able to cut with a knife, it's the material used to create the foam. You have foam concrete which obviously has air bubbles good luck cutting that with a knife, there is no reason foams are inherently weak. In fact there are some insanely mindboggling strong foam structures

I didn't mean that it had fixed that issue sorry, I mean't as we know the using concrete etc is not the weak point.

All you need to do is dip that post in tar to a few inches above the ground.

Yes there are some really strong chemical foams.

What I thought was great is that come the end of the fence, as they all fail sooner or later, instead of a lump of postcrete with a chunk of imbedded post you have something much lighter (and in this case possible to cut)

 

[Buffman]

Yes you would need 1 bottle per post, but with traditional postcrete/postfix you also need 1 bag per post:
https://www.wickes.co.uk/Blue-Circle-Ready-To-Use-Postcrete---20kg/p/221100

With bulk discount of postcrete, you are looking at nearly half the cost.



Issue I have with it, is that it doesn't look like the post is actually that secure in their video:
https://vimeo.com/261160707

My fence posts that I used postfix on, have absolutely no movement, where that video they seem to have some wobble.

Thanks for link, didn't realise I'd need so much postcrete! (a job worth paying for now rather than later though!)

Do you know if there's any issues fixing one post of the fence to the side wall of garage? (due to differential settlement etc?). I planned to make a vertical shadowbox fence

 

[Skiddley]

Call me olf fashioned, but would not touch this stuff. Must have used 100 bags of postcrete last year on vairious projects - no issue at all (other than cost). Probably should have invested in a cement mixer instead!

 

[Mark A]

Isn't the weight of concrete a big part of what keeps the post stable? I personally wouldn't trust this to hold up well long term.

 

[d_brennen]

Isn't the weight of concrete a big part of what keeps the post stable? I personally wouldn't trust this to hold up well long term.

When that guy was pretending to push the post in the video above I was just thinking that adding a big wooden sail like panel to that would see it upside down in next door's garden in no time flat

 

[R3X]

thanks for this post ts and others posting the info

I spotted the vids on youtube and almost fell for doing this quick and easy approach !