Have a customer who wants 24 fence posts 24″ x 24 ” x 6 ft tall built using round field stone with a concrete cap on top
I plan on putting them on a 24″ round X 36″ base using a plastic barrel for a form and filling it with concrete with rebar from the bottom of the form to the top of the post
My question is has any one done this kind of post and did you contrive soe sort of slip form to speed up the post building portion
we have done stone work and brick work in the past but nothing as odd as this and they want a estimate asap
Replies
I haven't built stone fence posts, but I would go about it by building a couple feet of the exterior at a time, and then pouring concrete with rebar in the center. To add more strength, drill rebar into the fieldstones at an oblique angle to the potential pull/fall out direction, and tie that into the center grid. masonry goes up pretty fast this way, I wouldn't expect that a slipform would make it any faster, but I guess I don't really know what you mean by that slipform.
I would make a jig that could hold up vertical stringlines about 1" from each corner. Makes it real quick to see if you're on course or not.
zak
"so it goes"
We just finished a similar fence. Columns were faced with Cultured Stone. Several different manufacturers, all with many different types, colors, styles, and column caps as well. The fake stone looks real enough and is easier to work with.
Columns were 3x3x3' footings with rebar, then square hollow conrete block 16"x16"x8" square. These were dry stacked and filled with concrete and rebar (continuous through/to footings). We put two foundation bolts in each side of each column before filling to attach redwood 4x4's. These became the basis for the wooden fencing between columns. 4x4's were treated with liquid epoxy anywhere they might be in contact with block or stone.
Cultured stone is mortared to block with mortar consisting of mortar and modified thinset. The thinset if for strength, while the mortar sets up faster. The stone had a stacked ledgestone look- no mortar joints, so we dyed the mortar to match the stone somewhat, so if any were visible it wouldn't be so obvious. Then a column cap.
Fencing was 2x12 kicker, 6' slats, 2x6 cap. Columns extend another 2" or so, then the cap. The stone came in panels and corners. Best fence we've built yet, but $$$. I think it was around $18K for about 73'!
I understand this company called ROX makes square blocks out of real stone. Considered it = faster columns but uneven surface to bolt to. The stone we've used from them is ledgestone type, so it's easier for them to fabricate panels and such. May be impossible with round stone.
WOuld you mine posting a picture if you can. I have a project in mind and would like to see some examples. TIA.
I'm envisioning some sort of rebar cage up the middle of each, like the kind used for concrete columns.
Perhaps a 3 ft high slip form at most because that is about the limit of arm reach for placing the face stones and the open time for a batch of concrete. You would bed a row of face stones in mortar against the form, then backfill the center with concrete, and repeat until reaching the top of the form.
On second thought, 2 foot slip forms with 3 lifts might actually be easier to manage. Since you may be floating work on 3-4 posts at once, no productivity penalty in breaking it up into smaller lifts.
The slip forms I have made have been plywood or OSB with 2x4 rails screwed to outside face on edge to brace. If you offset the rails by 1.5 inches on one pair and run all the railsl long, you can screw the "tails" of the rails to each other to form the box.
I cover the face of the forms with 6 mil poly to make them more nonstick. Makes it easier to reuse the form. I know there is some sort of 'release agent' you can buy, or some folks use an oil, but this method works for me.
With 24 of them, that's a big job. Good luck, and send pictures.
dude the form i have usedis a fiberglass slip form that i got from
my local construction suppy house it bolts together on the sides
and they also had form release agent that workes slicker than snot
it was 10' long and 36'" in dia.I carved it into# 4 -2.5' pieces that way
I can lay 4 posts at a time let it set up for a few hours then remove
the forms to work the joints.I use type 1 portland with rock meal[blue sand]
and masonry sand- fairly dry mix- makes joints look good very little smearing
the fence cavitys are made by laying cull brick as fill and then
removed when the form is slipped up.good thing about using type
one cement you dony have to wait around on it all day to work.DW
I don't see how the slip forms would work or at least result in a nice job. How do you point the mortar if it is hidden behind your form? How do you know if mortar has slopped through between the stones and onto teh faces?
Typically slipform is used when you just fill forms with stone and then pour concrete into the mess and hope that some DOES slop through between teh stone. The look is . . . well a slipform look, sith a lot of cement showing.
"I don't see how the slip forms would work or at least result in a nice job. How do you point the mortar if it is hidden behind your form? How do you know if mortar has slopped through between the stones and onto teh faces?"
The forms just keep the stones [perfectly] aligned against the concrete backfill.
You can adjust the prevalance of the mortar lines to some extent when you bed the stones in the mortar.
The key is to use mortar that is stiff enough to stay put.
The stones can always be pointed later to adjust the outward aesthetic.-The poster formerly known as csnow
done this kind of post
Yeap, solid & hollow, "real" & cultured stone both (including full stone & veneer).
For real, whole (full) stone, not much better to work from than a CMU core. The core can go on a foundation slab with or without a round pier underneath (it's whatever the engineer is going to spec in any event). You can get the core up quickly, then the stonemason can come in and "dress" them afterwards. With a CMU core, you can put either precast or solid stone caps on them ahed of time, too. Note that none of that comes cheap, even if you're building next to a quarry, the labor hours are still going to be high (especially what the stone mason will charge).
Going with veneer stone can help; six of one--half dozen of the other for a CMU core versus a framed core. That choice comes down to how the veneer stone is to be applied. If it's exotic and needs copper wire hangers--go with CMU.
Now, a framed core is much faster. You can often pre-assemble them, and then tapcon/e-bolt them to the foundation slabs (this is very nice for fence work, you can allign a batch of them to one stringline). Metal studs are very much a way to go, with 1/2" CBU making for a very long life as a fence post. Framed core is also a lot easier to get a tapered shape uniform along agreat long row of posts.
Cultured stone is nice way to get the project budget back under control (and usually the only way to keep the feature when the stonework comes in $85K over budget). The engineering for the foundations is a lot simpler, too. Don't forget that the cultured stone is easier to mix-n-match than "real" stone. So, you can have what looks like a rubble stone base transition into more dressed stones; or transition into what looks like once-stucco-parged brick.
Having been "helper" labor (only way to get the budget down low enough) hauling round river-washed rock to the mason to place--cultured stone has a very dear place in my heart (that, and never having to figure out what to do with 5/7 ton of "rejects" too . . .).
This type of pillar is something the Irish have been building for years. First put a vertical post or rebar into the ground and tie to it a piece of string the radius of the post. Place a rock to the end of the string, move the string round then place another, repeat until the course is complete. Mortar behind and between the rocks, keep the mortar back from the front edge if you want it to look like it is dry stack. Move the string up about the depth of the rock then do the next course. Repeat until you are up to the required height. For the cope, (the top of the post), put on a thin layer of rock which slightly overhang the constuction below it, then form up a shallow cone to make the pointed top,
Point up between the stone if required.
The Irish would then limewash the pillar. With a little adjustment and with a suitable heavy metal core post you could hang a gate off one of these pillars. The gate would actually be hanging off the metal post with the stone as an attractive veneer.
I note you are in Canada. Do a 'google' for the Dry Stone Walling Association of Canada, they might be able to give you more advice or even tell you where to get a mason who has built these pillars.
Hope this makes sense.
NICK
Thanks to one and all for the advice to date :
The site is across from a gravel pit & the existing home has this stone on 3 sides already thus the reason for the material selection
The idea of cull brick for rail insertion is interesting in how do you get a fixed length of rail between 2 fixed posts & have it into each post adaquetly
I forgot to mention that the client wants a patio built at the back of the house 10' x 50 ' using the same type of stone on the build up and a top of 1" random pattern field stone using river rock as a filler between the stones.
I propposed 6x6 beams for the sides to allow the mass to float in regards to frost heaving and she shot back that that might be ok if i could just put in some stone posts similar to fence but smaller however then the beams will try to lift the posts due to frost heave , man i should of been a engineer instead of a gc !!
mr.Dude when you take the forms off to dress the joints
remove the culls and dress the ensueing hole of course
this works for 2x6 or 2x8 planks/rails only, if using round
rails whatever size rail you are using ,use pvc stubs to form
the voids. after curing when starting the rail install cut the rails
the distance measured between the stone posts + the depth
of 1 and 1/2 the measurement of the voids . The idea is to
insert one endof the rail into the post then swing the other
end into 'just clearing' the other post then slidingthe rail into
the the other void. then either wedgeing or pinning the rail
between the posts so no movement acures. That way a person can
replace the rails as needed . DW
Gd interesting method the problem is i don't follow you as to the method could you post a sketch or better description
I met client 7.15 am this morning and she is pushing me saying she understands the costs involved ( glad she does ) and wants to get going.
It seems the DW got hert a doctor reciently when she felt terribly ill and she immediately had 3 new heart valves installed and she and her husband feel we saved her life so shje is determined this job will be done as pennance i think LOL
She is a gd early bird and knows i get up earlyier than her and starts phoning at 6:30 am whill i am trying to read the paper before 7:30 am starting time, Dam pest
Hi,
Unfortunatley I can't get a picture to go with this reply, perhaps someone could let me know how it is done.
I'll try and explain more clearly.
The method I described will give a circular pillar. When a piece of string of the required length is tied to a vertical post or piece of rebar it can be used to describe a circle - consider what happens when a dog is chained to a post and it can travel all round the post, eventually a circular path is cut in the grass.
The stones are laid so that the end of the stone reaches to the end of the string. The string is moved round the rebar to assist with the placing of each stone. This will produce a circle of stone. When the course of stone is complete pull the string up the pole and use it to lay the next course.
If proper care is taken placing the central pole and with laying the stone you don't even need to use a spirit level to get it plumb.
Take care to break the joints with each course, no vertical running joints.
The method could be adapted to produce share pillars but care would have to be taken with the corners.
NICK