Hello
I've started looking into what it would cost to build a wall instead of having a fence. Lecablock was half the price of lightweight concrete blocks, but I'm considering casting and filling with stones, as I have plenty of stones in the ground on the property. But what should I use to cast with in that case?
Thanks in advance /Jan
I've started looking into what it would cost to build a wall instead of having a fence. Lecablock was half the price of lightweight concrete blocks, but I'm considering casting and filling with stones, as I have plenty of stones in the ground on the property. But what should I use to cast with in that case?
Thanks in advance /Jan
Hi Jan,
When building a wall, you should drain a 30-40 cm layer and fill it with macadam to ensure that water cannot freeze at the "wall base."
It's less work with Leca/lightweight concrete since you don't need to nail forms or mix as much mortar. The finishing should be addressed with sheet metal or proper drainage.
With concrete, you can use your stones after washing if they range from 10-40mm in size (depending on casting width); I usually use 8-16 natural gravel.
With sand, gravel/aggregate, and regular standard cement, you're good to go. Depending on how exposed it is, you should choose a C-value/mixing ratio (usually listed on the back of the sack).
About 300-450 kg of cement/m3 is needed, and it's challenging to achieve a higher value than C30/37 when mixing by hand.
Vibrate to remove the air.
Best regards, Jawen
When building a wall, you should drain a 30-40 cm layer and fill it with macadam to ensure that water cannot freeze at the "wall base."
It's less work with Leca/lightweight concrete since you don't need to nail forms or mix as much mortar. The finishing should be addressed with sheet metal or proper drainage.
With concrete, you can use your stones after washing if they range from 10-40mm in size (depending on casting width); I usually use 8-16 natural gravel.
With sand, gravel/aggregate, and regular standard cement, you're good to go. Depending on how exposed it is, you should choose a C-value/mixing ratio (usually listed on the back of the sack).
About 300-450 kg of cement/m3 is needed, and it's challenging to achieve a higher value than C30/37 when mixing by hand.
Vibrate to remove the air.
Best regards, Jawen
Thank you very much for a very good response 
the stones we have in the ground are a bit larger than that, but if we take the smaller kind, they are about 1 dm or a little larger. but it should work just as well with cement?
regards Jan
the stones we have in the ground are a bit larger than that, but if we take the smaller kind, they are about 1 dm or a little larger. but it should work just as well with cement?
regards Jan
Member
· Västerbotten, Skellefteå
· 416 posts
yeah just go for it I poured a slab for a shed a couple of years ago and was half a cubic meter short on concrete when the concrete truck was empty...so we took a bit of everything to "fill in" with, there were large stones and some garden slabs went down too haha
I poured a slab for a shed a couple of years ago and was half a cubic meter short on concrete when the concrete truck was empty...so we took a bit of everything to "fill in" with, there were large stones and some garden slabs went down too hahaI cast a retaining wall for a basement staircase this summer and chose to use concrete blocks instead of building a form and casting the entire wall. It was both cost-effective and convenient, but you might not need to withstand earth pressure with the wall. In any case, building forms is both expensive and a bit tricky to make tight and stable. I would have used leca blocks any day of the week because they are so convenient.
One question is how high should you make the wall and how thick?
And should it be completely smooth or should it look like it's built with boulders?
But another thought could be to make the wall out of what's available in stone, and as some have written, it's quite expensive and time-consuming to build the form, especially if you're going to add some height, it needs to be done well.
If you're going to have it 1m above ground, it should go down 50cm into the ground unless it has a wide base that it stands on, which could reduce it a bit but still.
So what I can imagine could work is to cast the form first (i.e., take form plywood, make a frame on it, and place some rebar netting with some rebar sticking out here and there (which stick up when you cast it), and then you cast up in the frame (if you run with two or three-inch high edges) to get segments and don't need so many forms. Once you've made enough, you form them with supports and then fill the empty form with stones to the height where you'll make the first casting. If you mix in a tumbler yourself, do the bottom section and then go back to vibrate it together with the previous section, and continue like this. Since it will take its time, it will have set at the bottom and won't press against the form when you start getting higher.
But you will need quite a few people to keep it flowing, as one will be needed to fill with stones as it's being cast, and one will be fully occupied with mixing while at least one pours in and vibrates it down.
Then maybe half the volume will be from the stones you place in or perhaps significantly more, so it's a matter of mixing with appropriately sized gravel, so it can come in everywhere easily.
(I should add that this was a suggestion, and I hope for comments from those who have done a lot of such work if you have opinions on my suggestion):blushing:
And should it be completely smooth or should it look like it's built with boulders?
But another thought could be to make the wall out of what's available in stone, and as some have written, it's quite expensive and time-consuming to build the form, especially if you're going to add some height, it needs to be done well.
If you're going to have it 1m above ground, it should go down 50cm into the ground unless it has a wide base that it stands on, which could reduce it a bit but still.
So what I can imagine could work is to cast the form first (i.e., take form plywood, make a frame on it, and place some rebar netting with some rebar sticking out here and there (which stick up when you cast it), and then you cast up in the frame (if you run with two or three-inch high edges) to get segments and don't need so many forms. Once you've made enough, you form them with supports and then fill the empty form with stones to the height where you'll make the first casting. If you mix in a tumbler yourself, do the bottom section and then go back to vibrate it together with the previous section, and continue like this. Since it will take its time, it will have set at the bottom and won't press against the form when you start getting higher.
But you will need quite a few people to keep it flowing, as one will be needed to fill with stones as it's being cast, and one will be fully occupied with mixing while at least one pours in and vibrates it down.
Then maybe half the volume will be from the stones you place in or perhaps significantly more, so it's a matter of mixing with appropriately sized gravel, so it can come in everywhere easily.
(I should add that this was a suggestion, and I hope for comments from those who have done a lot of such work if you have opinions on my suggestion):blushing:
thanks for the answers!
I'm considering a wall about 1 - 1.2 meters high and maybe 2.2 dec wide.
One idea I have is to drain, cast pipes that are about 1 dec lower than the wall while casting a foundation, build a form that creates a section, lay a pillar between each section, the sections get plaster and white paint, and the pillars just white paint.
The pipes will be a bit deeper than the foundation itself so they become really stable,
the pipes plus reinforcement mesh should be enough for a stable wall?
and by building section by section you can take it a bit at a time.
any thoughts on this?
I'm considering a wall about 1 - 1.2 meters high and maybe 2.2 dec wide.
One idea I have is to drain, cast pipes that are about 1 dec lower than the wall while casting a foundation, build a form that creates a section, lay a pillar between each section, the sections get plaster and white paint, and the pillars just white paint.
The pipes will be a bit deeper than the foundation itself so they become really stable,
the pipes plus reinforcement mesh should be enough for a stable wall?
and by building section by section you can take it a bit at a time.
any thoughts on this?