I’m building some walls, 8′ high, with approximately an 8′ radius. Any suggestions on material choices for the forms? Thanks.
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sunsen- A dual set of 3/4 inch plywood plates works nice. Steel channel segmented with tin snips works...and they even make channel that bends to most any shape.
Stan
That sounds beefy Stan. Getting that plywood to do the radius might be tough though.
I've been thinking 2x4's, 12 o.c. vertically and strapping the studs like a wine barrel for the outer curve and just bracing the hell out of the inner. I'm wondering if masonite will do for the actual form walls. Layering it up might work. It's the only material I can think of that will do the bend easily and cost effectively.
The snap tie folks claim to have it worked out but I don't see their system being that easy to do the curve acurately with.
I'll send along a pic of the footings, which obviously aren't as substantial.
I'm also wondering how concrete guys do a really long curve with an inconsistant radius and elevation...? Just eyeball it?
I formed some compound (both ways) curves recently.
I spent a lot of time walking back a little ways and eyeballing it.
I figure if the forms look good then the concrete will too.
It helps to figure out where the curve is going to start and stop first.
Then you string a line or snap one.
Then pull out from that straight line where the middle of the curve will be.
If you do everything by eye it can get catywonk and hurt your brain. "There are three kinds of men: The one that learns by reading, the few who learn by observation and the rest of them have to pee on the electric fence for themselves."Will Rogers
I'm having the idea that laying out the footings with a rope or something would work.
I wonder how those guys who build freeway overpasses and such with long, graceful curves and lots of form work do it.
You can take symons steel ply fractions and make a segmented curve that looks pretty decent. Just put a bunch of 8" fractions together. Masonite works and looks nice but takes a lot of time. What kind of forms are you using for the rest of the foundation? I have also used duraform/advanced forms and used a bunch of fractions of make a segmented curve. I would like to see pictures when you are done. Looks like a fun project.
I'll be using snap ties on the straight walls. I'm familiar with the use of those, having built a basement or two. It's the curved walls that have me questioning material options.
I'll post a pic or two when the thing's complete. It is kind of fun. I dreamed up the design to accomodate a cut in the hillside that the well driller made to level up his truck when drilling. The well head is in the christy box in the foreground of the pic. If I ever sell the property I'll market the underground building as a "wine cave", heh, heh. It's close enough to Napa to get away with that.
You are using plywood with snap ties?
Yes, 3/4" with double whalers 24" o.c. I've used them before when pouring 12' tall walls and they're plenty strong. The straight walls are no problem, it's the curves I'm wondering about.
Sounds like you have one side of the forms up, or at least one layer. Right?
Just now saw this thread.
8' is a fairly tight radius.
Build you inside form first, using two layers of 3/8 plywood or masonite or three layer of 1/4". (This is backward of the normal form wall construction, but works for a radius wall.)
You layer your bending forms on the plate and layer it toward the inside and stager the joints in the layers more than two feet from one another. Add stiff backs (like short studs) at 1' oc and extra where needed to fair the curve. BTW, the 4x8 sheets should be laying on thier sides, not standing up, as in a mormal foundation wall form job.
Duplicate your plate curve with 3/4" plywood on top on your stiff backs.( May as well make another set at this time for the middle and top of the form. Now start your outside forms. The tricky part comes now because you need to add the snap ties so they line up with the stiff backs on the inside form. There may or may not be some rule of thumb for how many and where you need them, but we never knew it. (we just kept adding ties untill the outsid form matched the inside form and didn't have any large flat spots in it) If you are using the Gates system the camlocks are also on sideways to the normal position, so you arent going to be adding whalers.
After you have both the first 4' high runs of inner and outer forms set, you duplicate it all with the next 4' of forms setting on top of them. When that is done go back and add some full lenght stiff backs over the shorter ones and set your braces and plumb the whole shebang.
Pour it slow and easy in 2 to 3' lifts around the radius. If you are good with the vibrator you can dick it quickely to keep down any honeycombs and layering in your lifts. If not just rod it good on each lift and pound on the forms with a block and hammer for the same results. Over working a radius wall with a vibrator is much easier to do than on a straight wall and blow outs are the results.
Hope this is a little help.
I've done a few of those buggers with larger radiuses. Yours would scare the bejesus out of me, and I would contract it to someone with those old steel bending forms. <G>
Thanks for the input Dave. I've already built the outside forms for all my curved sections and will be heading up to the job site tomorrow to tie steel. I'm doing it a little differently than you recommend but the main thing I'm taking away from your advice is pouring slowly. If I go in two foot lifts and allow some time for setting up I expect to be okay. It is a tight curve, no question about that. I'll be careful with the vibrator also.
I've only used masonite (tempered hardboard) on sidewalk forms, so don't know how it will react to as much concrete as you are going to be loading it with. I know the stuff swell up like crazy on cut edges when it gets wet. We never oiled sidewalk forms either, but I think I would seal or oil the inside of those form pretty good. The oil should soak in enough to keep the stuff from going wild on you when it gets wet.
I know you are going to cover it with stone, but it always made me feel like rookie to wreck a form and see butt ugly waves in thecrete.
If you can afford the time, let those forms stay up as long as you can,. The longer the wall gets to wet cure in the forms, the better the final strenght will be.
I'll be using form release oil on all the forms and I will be building a concrete roof on the building, which requires support for a long period of time, till cured. That means the wall forms will be up for at least as long what with the way I'm building the thing. I'll let everything cure the 28 days at a minimum.
I used masonite on the forms for the footing along with form release oil and everything went as well as I could imagine. The footings were 15" in height. I posted a pic of the result earlier in this thread.
I'm thinking if I go slow with the pour and brace everything really well I should be okay. The forms that I've completed don't look wavy but I'm sure if the sunlight hits them just so they wouldn't be a perfect curve either.
I'm headed up there again tomorrow and I'll try to remember to bring a camera so as to illustrate.
Thanks for the advice.
Let us know how you like tieing that rebar on an inside radius.
that is the bi reason I said to set the inside form first. It is much much easier to wrap piece of 20' #4 bar around the outside than it is to get it pushed into the inside curve.
Hope you have somehelp. It will take some extra hands.
Bending the rebar doesn't seem to be a problem. I anchor one end and walk it around. Tying to the verticals makes the curve pretty accurate.
My last post was a bit misleading. When I say I anchor one end and walk it around I mean I bend the entire bar first, outside the form area, then bringing the bent steel to tie onto the verticals. Not too difficult to do by myself. I'm using schedule 40 #4 bar.
WE take a string line, a stake, and some paint. Lay out each segment of the curve and form up to the paint lines. Two layers of either "bendy plywood" or tempered hardboard, screwed to stakes AT the grade needed. Wire the stakes together ACROSS the top of the forms. A wall or just a parking curb, it all starts with the form work. On inside curves, add a 2x4. Make "kerf cuts" every few inches so that the 2x will bend. Screw 2x to forms on the inside radius of the form. Yep, Im a concrete guy AND a "rod-buster".
Wow, being a carpenter I think I may be over doing it, LOL! In my defense, these are eight foot tall walls.
I'll use your method when attempting a three foot tall retaining wall that follows the terrain. Thanks.
Stan, I misread your post earlier. The plates are cut. I did those on Friday; out of plywood, same as your suggestion. What I'm wondering about is the bent material. Masonite your best bet?
Corrugated metal would give an interesting look.
I'm really looking for smooth walls. To be veneered with stone at some later date.
Masonite will bend easy. So will 1/4" plywood ... 3 layers if you think you need them. With the curve, you may not need as muc since the curve itself is very structurally stable. May only need two layers. You still need uprights to give it bulk strength for the pour. You doing the pour yourself?
You are pouring concrete, right? I read the hint in your original posting, but by the reactions, I wasn't sure.
Yeah, I'm thinking masonite would work best. I'll just staple it up after raising the frame. Probably don't even need any form release oil on that stuff.
Is masonite typically what is used in this situation? I can't think of any real drawbacks. It's certainly cheap enough.
Downside is that it may literally fall apart w/ the moisture from the concrete. it has really zero resistance to water and for a couple of hours, It'll be soaking wet. Plywood will retain some strength. I'd check. Plywood may be cheaper C-D grade.
I used masonite when forming up the footings, (pictured in my post above), and there was no issue with moisture at all. Concrete sets up pretty quick around here at this time of year. The reason I'm wondering about masonite is because it doesn't seem super strong, even with 12" o.c. studs, and there will be some pressure at the bottom of the pour. Especially when vibrated. I'll pour in lifts though so I'm figuring it'll be alright. That's why I'm wondering if anyone has done 8' tall curved walls and what they used.
When forms get high like what you are doing the pressure/weight gets pretty high.
Especially if you vibrate them.
I've seen tall pours move and it's not pretty.
The masonite is pretty weak to start with and when it gets wet even more so.
I'd use plywood.
One other thing. Your vertical studs most people do well.
But a lot of people forget about the whalers. You need strong horizontal members in a couple of places up the wall. Especially at the top.
That is what happened on the pour that moved I was remembering.
No whalers. The whalers keep the vertices in alignment. Otherwise part of the wall might bulge out at the top.
Just my two cents. "There are three kinds of men: The one that learns by reading, the few who learn by observation and the rest of them have to pee on the electric fence for themselves."Will Rogers
That's why I'm intending to strap the outside radius' and brace the inside curves top and middle.
I'm looking into something called "bending plywood" that a fellow mentioned in an above post. I've never heard of the stuff but maybe it's worth the trouble to source.
No problem sunsen. Just relating how I would do it."There are three kinds of men: The one that learns by reading, the few who learn by observation and the rest of them have to pee on the electric fence for themselves."Will Rogers
Masonite over at least 1/2" plywood or you will wind up with concrete feet.I posted earlier to use a double layer of 3/8"plywood if it bends easily. If not use 3 layers of 1/4" plywood.I believe he said the walls are 8'-0" high, masonite alone has no strength. I have used it for curbs and such but not a wall.
mike
Are you sure about masonite being a problem Mike? I used it for the footings with no sign of movement whatsoever. The forms for the footings were 15" but I intend to pour the walls in 2' lifts. Concrete sets up pretty fast, especially in 90 to100 degree temps we get around here. By the time I make it around the forms one time I can't see that much pressure being exerted at the base of the previous pour.
I've already built the outside form with studs 12" o.c. and two layers of 1/4" masonite. If I use snap ties on the same layout as the straight walls the studs won't be going anywhere. I know this from previous experience. So essentially it's 1/2" of masonite holding back less than two cubic feet of concrete, if the lower lift has set up enough to relieve pressure. I figured my biggest concern would be a cold joint, so I have to be careful not to wait too long before lifts.
I can bend the steel pretty easily by anchoring one end and walking it around. Tying to the vertical bars pulls it into place accurately. I had this experience with the steel in the footings.
I appreciate the input as it's good to try and think these things through.
1/2" of masonite to hold concrete in a wall 8'-0" high? I would not take the chance.If you only have a few hours into this I would stop now and rethink this.
If you go ahead, at least add another stud inbetween the 12" centers.How are you going to tighten the snap ties> With only 1/2" on each form you will be 1/2" short.You will need 1/4" plywood washers or double up on the hairpins. Either way you may pop the tie thru the masonite if you are not careful. I've done that on 5/8" and 3/4" plywood a few times by accident.
Google the Gates System site, hire a carpenter for at least one day to show you the ropes for this system if you are not familiar with it.His pay will pay off in spades,make sure he has done curved work with the Gates system.
I don't want to scare you, I take that back.I do want to scare you out of using masonite for an 8'-0 high wall.I know you think that a hot day pouring and an even flow height will reduce the pressure. To an extent this is true.I don't think you can pour slow enough without badly cold joints to escape a blowout.
Pouring a footing is different than a wall.You can get away with not consolidating a footing with the vibrator is most cases. You must vibrate the wall. The more I think about it the worse it seems.
I hope whatever you do you come out on top,don't get hurt over this job.
mike
Pop the snap ties? That doesn't make sense to me. I'll post a pic or two of the last basement I built. As a matter of fact, I'm using the same wedges pictured here. I've got a ton of those things, heh, heh. Anyway, this is the system.
The masonite only takes pressure on the area immediately surrounding the snap tie, (1' away), and of course from above. Lifts are the way to eliminate that downward pressure.
I already have a ton of time into the curves so I'm committed. I'm just thinking of ways to beef it up; easily that is.
I tried to say pulling the washer head of the tie clear thru the sheathing,whatever is used ,masonite or plywood.Very easy to do on masonite.
good luck, you'll need it.
mike
Oh, I get what you're saying about popping the snap ties. I've figured out how to do those on the curve although it's tougher to explain it than do it. I don't think that will be a problem.
Actually, if you think about it, the volume of concrete being retained by any one section of masonite wall with 12" o.c. and 8" thick walls is very small, if you exclude downward pressure. That is assuming the wailers, (studs), are solid. That's something I can insure easily enough. Like I said, the downward pressure is handled by the lift technique. Of course, I'll also be monitoring the forms for any sign of stress so I'm not super concerned.
I did not know the walls were only 8" thick, this makes for a faster pour. You would be better off with 8'-0 thick walls.The wider the wall the less pressure,sounds like I said it wrong.I said it correctly though.Even though the volume would be tremendous in a wall 8'-0 thick the pressure would be less. You will build pressure fast on an 8" wall.
mike
Well, at some point it's all about head pressure, I suppose. But an 8" thick wall is going to exert a whole lot less pressure than an 8' thick wall, much the same way an 8" thick layer of dirt saturated with water is going to exert less pressure on a retaining wall than a hillside saturated with water. I'm pretty sure of that.
It's really up to me how fast the pour goes and I don't suppose luck has a whole lot to do with it. It's about whether the forms are strong enough to support the amount of pressure applied by the wet concrete, which, ultimately, is under my control by regulating the speed of the pour.
An old engineer told me that water stands straight up, Sand, Wheat and Concrete push out.Look at your local water tower (if you have one), then look at a new concrete grain facility.Are you pumping? Planning a slump test first?While some curves have in built lateral resistance, that last pour will tell the tale.Have you thought out how you can measure the forms during the pour to see how things are going?
Yes, I agree, there's some element of that. I guess what I was trying to say was that if the concrete was wet enough there's head pressure involved but there's mostly the slide factor, as in sand, wheat, etc. and I'm sure that doesn't dissipate until quite a ways further from the straight up and down edge of the pour than 8". It makes sense to me but perhaps I'm not communicating particularly well.
As to measuring the forms and movement, it's been my experience that you can tell by looking and listening.
This will definitely be pumped. I'll pour a fairly stiff mix. I suppose I could even use an accelerator but in this heat I don't suppose it'll be necessary.
You're correct, I'll learn one way or the other on the day of the pour.
I wouldn't use and accerator but would use a supper plastizor. You can pour as stiff as you want with it as an add mix and the concrete will handle like it it is much wetter.
Are you doulbing your stiff backs at your wall ties? The stiff backs are the vertical braces. Whalers are the horizontal members in your pictures that you wedges are locking over.
I haven't used that system in 30 years but seem to remember that the whallers have to be there to act as backers for the wedges. correct me if I'm wrong.
Yes, the strong backs and walers are all double in the system I'm using. However, in the curved wall sections I'm having to devise another setup, because of the curve.
I can build the curved wall strong enough to hold, stud-wise, there's no doubt in my mind about that. The issue is how much pressure can the masonite take. Essentially the stud spacing for masonite is what I'm most concerned about.
I've used water reducer before, which is or has the same effect as the super plasterizer you're talking about. I'm questioning whether I want a more fluid mix or not. I suspect this would have the same effect as vibrating from my results standpoint. I'll be vibrating anyway.
I like tje water reducer because you get a high initial flow from the concrete and it reduces the need to vibrate as much. Most blow outs I have been involved in came from over vibrating and inadequate braceing at the bottom of the wall.
I have never formed with anything less tha 3/4" forms and in the case of the few radius wall the laminated thickness was also 3/4".
Are you dropping out of the truck shut or using a pumper?
I like the idea of not having to vibrate as much, that's for sure. That's the part of the process that has me most concerned. I'll check into this with my supplier up north where the job is. He seems pretty knowledgeable.
My only real question is how much stress will be transferred to the bottom of the forms when vibrating, given the concrete at the bottom of the forms has been allowed some time to set up. That's why I'm thinking accelerant. Get a little stiffer base. Vibrating less would seemingly have the same result.
I always have a pump up there because the concrete company I've been using sends a couple of guys along who actually place the concrete for you. They know what they're doing and since I'm working alone that's a real bonus. Where I normally build, (those pics are from a job in Palo Alto), the most a pump guy will do is operate the on off button so myself and crew have to do the work. We don't do concrete every day so that's a hindrance.
By the way, when you did your curves, with 3/4" material, what was the spacing on the 2x material?
Also, in your blow out situations, what was the thickness of the walls? How was the bracing done? Was it failure of the 2x frame material or the 3/4" skin itself? If the skin didn't fail at all then I'm much more condident in my 1/2" of masonite. I really don't think the main stress is on the skin, unless the stud/strong back spacing is too infrequent.
How about fastening at the bottom plate? Was that the cause? Did you use snap ties in those situations? I think I could learn a lot from what has failed in the past.
I had one blowout on some curved steps I did some 15 years or so ago. I know it was inadequate bracing on that one, not the sheeting. Kind of a different situation than these walls though.
I really appreciate your input Dave.
My worst blow out was a single form pour for a friend. It was all "my bad" as the kids say. I poured the footing one weekend and single formed the short wall the next weekend. I didn't brace it untill the following weekend of the pour because the braces would have blocked the friends driveway.
Of course you know what happens on the morning of any pour. Small or large I am always frettting over some detail I think I forgot. I should have been adding more 2x material from the form plate back to the stakes in the driveway, instead of thinking about anchor bolt placement or whatever else had my head up my butt.
Lucky me. It was only a 4 yrd pour on a 4' wall, and I was the only one on top when it failed. I got a piece of #4 rebar in the one butt cheek and a few other scrapes and bruises but knowone else got hurt. Aside from the embarrasement and the hustle to reset the form and shovel about 2 1/2 yds up and back in, it taught me a valuable lesson about bracing. There is no such thing as to much bracing, more so if you are doing a single form.
BTW that was a freebee job to boot.
I've never done as tight a radius as your pour. IIRCC the smallest curve I ever worked on was 16'. It was a foundation wall of a bank and only 4' high. The same bank also had a 28' curved wall. We formed both curves the with the same build up of 1/4" plywood to get the 3/4" thickness needed for the Gates forming system. The walls were 10" thick I believe .
The biggest blow out I ever wittnessed was on a University of Louisville building. Something like a 16' high 12" wall blew out on about the third lift. Instead of switching vibrator hose lengths after the first two lifts they continued to use the longer one. Must have kept running it all the way in cause that sucker let go like a run away freight train. I was next door to the site on another project so the sound was my first clue. No one got hurt on that one either. Must have been 30 yards on concrete spill out of that wall before they got a hi-lift to push the breech closed. Glad I didn't have to shore and brace the sucker back up.
I'll bet the vast majority of blow outs are due to too fast a pour. My last pour I sliced each form into 3 pieces and didn't brace anything.. Plus I put the forms on top of the form for pouring the footings.
I poured nice and slow and never had a hint of a problem..
On continous wall pours you dour in lifts. Go to slow and you get semi cold joints in the wall. It is all a balancing act of timing, speed, and slumo.
After being involveld in a couple of blow outs I'll overkill the bracing. You can;t imagine the work involed in shoveling yards of concrete awy from a blown form, resetting the form, bracing , and shoveling concrete back in the form or out of the hole. And, all that has to be done fast because all of it is setting up on you. You stand a very real chance of ending up with a big cold joint in a wall. In commercial work that will more than likely mean you fail the inspection, eat the cost of tareing it all down , and doing it all over.
Over vibrating is probably right up there with bracing for blow out causes. Guys tend to use a vibrator to move the concrete around the forms instead of just sticking it in and pulling it back up. I know one residential guy that won;t even use one. His guys just rod the heck out of the pour and then beat thehell out of the forms with blocks and hammers.. A lot more work for his crews but he hasn't had any problens for years now.
Yeah, I can imagine folks getting in trouble with a vibrator. I just drop it in, pull it out, move on down the line. Works great.
I've found that pounding on forms can actually cause more movement.
So, have you formed and poured it yet?
I'm wait to here about the pour and how it went.Pics Please
Still forming. Another week or so and I should be ready to pour up there. Depending on scheduling that is. I'll try and remember to bring a camera.
This might be a bit late but here goes: take a sheet of 3/4 plywood, lay out and cut the shape of the curves you need, do enough that you have THREE PAIRS of these. Cut some 2xs to go between each pair of curves and screw two of them every two feet along the curve. Leave just enough space between the 2xs to allow your wall ties to come through and be "dogged off'. Attach the Bendy-ply to the "inside' of these to make up your curved forms and fasten them to the footer through the bottom curved plywood. Add turnbuckle braces near the top to plumb and brace the forms. Like I said, a wee bit late, but next time, just make four 'pairs' of these form-backers- base "plate", two in the middle and one just below the top of the form. Just a thought.
I finally got around to taking some pics. I was up there the last few days forming the roof of the "cave".
The masonite worked great on the curves.
Thanks for the up date. Wow looks like a lot of work. Great job!!
How did you place it Pump?Now we have to see more, Keep us updated.Thanks again, work safe.
Thanks. Maybe I should have titled my post "how I spent my summer", heh, heh.
The folks I buy concrete from up there have an in house pump service and the two fellows who come with the pump placed the concrete while I did the vibrating and topping off. Down here in the bay area the guy who comes with the pump lays out the hose and pushes the on off button for you, that's it.
The forms held up great, especially the curves, which was the original reason for my post.
Looks good.
Nice and clean.
Life is Good
Thanks. I'd best not post pics of the lower portion of my job site where I've poured piers for the foundation of the main house. It's looking a bit of a mess what with over grown weeds and all, heh, heh.
Just got back to town from working on the forms. It's a lot of work for one guy and the heat lately has been slowing me down. I think I'm getting too old, heh, heh.
I think I'm getting too old, heh, heh.
Nah.
Look up old in the dictionary and you get an 8x10 glossy of Piffen, or any number of other guys here.
Hi Dave,
Just back from tying all the steel. I phoned my concrete guy from here in the s.f. bay area, (my little project is a couple hours north of here), to ask his opinion on my forming situation. Turns out he has quite a bit of experience with using masonite for curved forms. He's from Jamaica and has worked all over the planet doing concrete work. Apparently, as in Jamaica for instance, there was a time when they couldn't get plywood so they used masonite for forms on a regular basis. He says emphatically that 1/2" of masonite will work beautifully for my curves with the snap tie system. It's all in the bracing, which was my gut anyway. As a matter of fact, in other parts of the world they don't even use snap ties but instead use a 1/8" steel tie wire. It's my understanding that you drill holes in the walers and there's a special twist tool to tie them off. He says that if you know how to time it you can pull the tie wires after vibrating and before the concrete sets up completely and the hole disappears. Obviously, he's a lot more confident than I am. I'll go with the snap ties and patch the holes, heh, heh.
I'll try and remember to bring a camera up to the job next time I go and post a pic or two.
That Louisville job sounds horrendous.
Tom
Masonite wil work. I would use three layers screwed to each other. Depending on stud spacing , vibrating may bend the masonite between the studs. You might want to condsider a couple rows of horizontal blocking near the bottom. As for the moisture affecting the masonite, you could spray adhesive 6 mil poly on the form face,and caulk the bottom edge. It would take some effort to kee out wrinkle but would give a really smooth surface.
Yeah, I'm not concerned about moisture, it's the pressure during the vibrating process, especially at the base of the pour. The blocking idea would work, I'm just wondering if that would be overkill. That'd be a ton of extra work on the curve. I'm thinking three layers of 3/16" with stud spacing at 12" o.c. should be enough. I supose I'll find out, heh, heh.
Why not multiple layers of bending plywood?
Jeff
I'm still mulling that option. Plywood is stiff enough to cause it to straighten out though, especially at the ends, where the joints are. It'd be kind of nice to really get a round wall.
I'm not saying, bend plywood.
I'm saying - USE BENDING PLYWOOD - it's a specific product made for this type of application.
Jeff
Now that's the kind of information I was asking about in my initial post. I've never heard of bending plywood. I've use italian poplar in cabinetry and it will easily do the radius but I can't for the life of me imagine concrete guys paying for that stuff. I'll ask around about the product you're talking about.
When forming my curves the guys used a range of straight forms in skinny widths ranging from 6" to 24" to make the curve.. can you get skinny forms?
I think the masonite is going to work. I've got a nice curve on the thing, having just returned to my computer after being up there working on forms all week.
Bending plywood is for interior use,I do not know but I am guessing that it would be a disaster,worse than masonite.
mike
I fail to see anywhere what function these walls will provide. Your footing layout looks like an outdoor kitchen or landscaping project. What's the deal?
With such an elaborate design and construction of the footing, certainly there's some plans or details somewhere being called for
.
This will be an underground building pretty much tucked into the surrounding hillside. The footing in the foreground is for a retaining wall, 8' in height at the peak. The building will be 8' also. The engineer specified the footings. It's in earthquake country.
In that case, I'd consider putting the stone (real) up now. Build it so it's able to withstand any lateral and vertical loads. Where it joins a conditioned space, spray foam from the inside and carve to need. Trowel your surface as desired.
This thing is already engineered so I'm committed to poured in place concrete walls. Veneering the whole thing at a later date works best for a number of reasons. It's not a conditioned space and stands alone.
Sunsen: Bending Plywood is roughly three ply wood w/ the grain running the same direction in all three plies. Really willowy in one direction, stiffer than heck in the other. You have to go to a REAL lumber yard that has all sorts of different goodies to get it. Home of the Pot doesn't carry it, nor does their counterpart w/ the big blue sign.Was the footer for this 8 ft high wall engineered, also? Is it going to have earth on only one side? Eight feet up? I'd hope that there is significant footing to hold that much earth back for all eternity. I searched the web for info for design of a low - 4 ft - retaining wall I'm building & it got pretty tacky. I discovered that I had to go back to the drawing board & start over, requiring a significantly greater pile of dirt when I was through digging the footer hole.DonDon Reinhard
The Glass Masterworks
"If it scratches, I etch it!"
That's interesting about the bending plywood. The lumber yards in the neighborhood of my project didn't have any such item so I went with masonite. I suppose I'll know whether or not it was a good call on the day of the pour, heh, heh.
Yes, the walls were engineered and I'm pretty confident they'll hold up. There's a ton of steel in the design along with some pretty hefty footings.
I believe you can bend 3/8" plywood to an 8'-0 radius.You would have to double up though. Gates ties and hardware with the sheets laying down are perfect for this. Make the plates out of 3/4" plywood. I cut the plates with a router. I swing the radius for the first piece. Then use it for a template. I use a 1/2" top bearing bit .
You only need to cut the top and bottom plates not walers.No walers are neccesary using Gates system.Lay out studs as you would for a straight wall with Gates hardware. I use a cheap center square ( the combo square with the V shaped head) to square the studs on the curved plates.Remember that the wall ties will be splayed, the inside form will be 15- 3/16" centers but the outside form will be a larger distance between centers.I would have to actually lay it out and know the wall thickness to give you the correct dimension.
mike
You might use ICF's I did for my portico's went pretty nice sure was simple.
I'm pretty much committed to the current course of action, what with the engineering and all. Not to mention everything's halfway built at this point.
Neat thing with ICF's is the engineering is done for you.
Why not call a precast concrete pipe company in your area and just order up two 4 ft sections of 96 inch pipe?
"Why not call a precast concrete pipe company in your area and just order up two 4 ft sections of 96 inch pipe?"
That's easy - COST (waay too expensive)
That would be an unbelieveably expensive option. I'm not exactly a wealthy man, heh, heh.