DIY Home Improvement Forum banner

Lots of newbie Concrete Fountain Questions!

6K views 18 replies 6 participants last post by  stadry 
#1 ·
Cross posted from another forum. If this should be in "Crafts" rather than "B&C", apologies.

Thanks to anyone with the patience to respond, Im trying to cover all my questions, and am a total neophyte so am providing quite a bit of detail. If there is a resource where most/all of this is answered then Id appreciate a reference.

Ive read a lot of DIY concrete info (sometimes conflicting), and want to limit the chances of screwing up!


Here is the project: Basically a concrete slab, approx 28 w x 40 h x ? thick, poured with 1/2 PVC pipe embedded to deliver water pumped from a bowl to the top of the slab. The PVC will protrude from the slab slightly at the outlets, with tile fitted around the PVC outlets, and the slab will be ceramic tiled and framed with a molded concrete border tile. The bottom of the slab will be formed with a large gap (~ 9 inches high) to accomodate inserting a bowl to catch the water and the PVC input. The remaining area on the bottom will have "feet" out of the front only so it will stand with attachment. (it will be positioned against a wall so need for support to the back). Id like to pour the entire slab in one piece, not attach the feet later if possible. The entire project will sit on a rectangular concrete base.


Here are my questions: How thick does the slab need to be for sufficient strength but limit the weight? (I assume the recipe will include fiber reinforcement.) The couplings for the embedded PVC are probably a little more than an inch in outside diameter. Recipe suggestions for the slab and the block (if different) ? As light as possible that will accomplish the job. Its Southern California so freeze/thaw is not a concern, and the temperature during pouring in the 70s, relatively low humidity.

Depending on the thickness, the slab will be 2-3 cubic feet, the base around 9 cubic feet. They will be poured at different times (and maybe different recipes if recommended above). Will hand mixing in a large bucket work (in batches for the base), or do I need to rent wheelbarrow/mixer? I do have a paint mixer attachment to a hand drill if that would do the trick.


For the "feet" at the bottom of the slab, is rebar needed? L shaped? Rebar in the veritcal rise of the slab? Does there need to be some time for the bottom of the pour to harden before placing the PVC so the weight of the top of the pour doesnt push the PVC all the way to the bottom. Similar question on the rebar ( if rebar is needed).

Since this will be a wet environment any recommendations on cure/waterproofing sealer (that will allow for adhesion of thin-set for the tile)? Recommendations for the thin-set for the tiling? Grout? (must be white).

I assume wood is fine for the walls of the form but what about the 28 x 40 bottom? Will a wood bottom release after sufficient curing time or do I need to expect that to be permanent (and therefore need to use a higher quality wood/material) since it will bear all of the weight of the concrete during curing.

Recommendations for the release to be used? How do I know when the form should be removed? How critical is the timing for removal of the form? (Ie will watiing too long after it is sufficiently hardened result in difficult/impossible release?)


From what Ive read, waterproofing sealer/cures are best applied right after any bleed water is absorbed. After that I assume the project should be "bagged" for curing? I would add posts to the form to support the bag so it doesnt fall onto the slab, but how "tight" should the clearance be to recirculate the moisture for a good cure? And most importantly: what should I have asked and didnt!

Thanks again for reading if you made it this far!
 
See less See more
#3 ·
Thanks for the reply Willie



No, I dont have a drawing yet, though since its mostly straight lines I could probably draw them up fairly simply. (I am considering an arched top now, but I can rough that out).

Is it permitted on this forum to post images?
 
#5 ·
what is going on top of the slab ? this will help determine the thickness. cars, peoples feet, ?
i would not bury the pvc in the concrete, may cause it to crack some day.(the pvc, not the concrete) run the pvc under the concrete in some gravel. if it were just for wires the embed would be ok, but your carring water, you dont want any leaks later. you will come up through the concrete vertically, thats ok.
 
#6 ·
There is nothing on top (once it is out of the form and vertical it would be tombstone shaped). The front face is clad in tile and molded concrete trim pieces. The top may be an arch or it may be flat, depending on how well the tile cuts.

Im not quite following your point on the PVC. Are saying to fill the form partially with gravel, lay the pipe on that and pour the concrete over that? The "back" after removing it from the form and standing it up would then be a partially exposed vertical PVC run with some gravel adhering to the concrete and surrounding the rest of the PVC? When the feeder PVC reaches the top it has to bend to horizontal, and then PVC (to the 3 outlet holes) from that portion of the feeder to the front of the "tombstone". Those 3 pieces have to go through the concrete.

Effectively the finished slab would be partially "hollowed out" except for some gravel partially surrounding the main PVC feeder?
 
#11 ·
There is nothing on top (once it is out of the form and vertical it would be tombstone shaped). The front face is clad in tile and molded concrete trim pieces. The top may be an arch or it may be flat, depending on how well the tile cuts.

Im not quite following your point on the PVC. Are saying to fill the form partially with gravel, lay the pipe on that and pour the concrete over that? The "back" after removing it from the form and standing it up would then be a partially exposed vertical PVC run with some gravel adhering to the concrete and surrounding the rest of the PVC? When the feeder PVC reaches the top it has to bend to horizontal, and then PVC (to the 3 outlet holes) from that portion of the feeder to the front of the "tombstone". Those 3 pieces have to go through the concrete.

Effectively the finished slab would be partially "hollowed out" except for some gravel partially surrounding the main PVC feeder?
I thought you said you were pouring a slab, now it sounds more like a tomstone. :huh:
 
#7 ·
certainly hope that's INCHES you post :laughing: if its feet, you'd be looking 72 tons at least :yes: buy some buddy rhodes countertop mix & save yourself all that trouble of learning conc,,, sure, you might f up the 1st 1 but so what ? ? ? you don't have to make a living doing this & it is fun :huh:

hopefully this piece of art'll be inside 'cause the tiles'll pop off if its subjected to freeze/thaw cycling,,, extreme heat can cause the same result,,, far's running the wire, support some flexible plastic tubing on ' chairs ' of some sort to keep it in the center - you'll pour flat, right ? ? ?
 
#9 ·
wps, I thought I understood what you were trying to do. But as I keep reading, it gets confusing. My initial thought is that you are trying to make a water feature similiar to the ones that you see on those DIY/HGTV shows. If so, I think you may have a few flaws in the design. When you initially mention slab, you are referring to the waterfeature before you stand it? You mention leaving 9" gap at the bottom so the bowl can fit in it, and feet around it for support. Are you going to have enough room to install/hide the water pump? If up against a wall, why not just leave it off the wall an inch, and run your pvc piping up the back? If embedding the pvc inside, you will probably need at least 2" thickness. You will want about 1/2" of concrete between the back and the piping. Your 90, to get the water out the front, will give you about 1". Instead of feet, how about making the slab 1 foot taller, and have it embedded in the ground. Maybe you can put some pavers in at the base to give it a cleaner base.
 
#10 ·
Yes I think you have the picture. The bottom of the slab is theback of the fountain once it's standing. Instead of running the PVC upthe back I assume I can pour a channel for it to be placed in after curing. Or I could pour a lip around the back(bottom of the slab) so the lip is flush to the wall and the pipe hidden on inside. Either one better? Weight wise the secondway I would think. When the outlet pipes run from the back and out the front can they be embedded without cracking concerns? Should they just be poured as holes with a little tolerance and feed the outlet pipes through later?

The reason for raising it on a pedastal is to be out of reach of pets. The water will be treated with Chemicals.

The pump is submersed in the bowl. The power wires and water tube will just come up and out of the bowl. That is the reason for the gap by pushing it deep enough it will hide that stuff and ensure the water is all caught.


Thanks for your thoughts. If you know of anyHGTV episodes let me know!
 
#13 ·
Exactly! I thought using a term of art like slab would clarify not confuse things! So how do I get the water from the pipe in the back and out of the R I P in front?!?! With minimal cracking risk of course.
in your case its probably not a problem. you could wrap the pipe with some thin foam like the blue stuff they sell as sill seal for buildings.
put some wire mesh in your concrete, dont rely on the fiber stuff alone
 
#14 ·
Thats encouraging! how about the blue tubes of pipe insulation instead of the sill material? does whatever its wrapped in need wire mesh (like lath) around it? I havent seen anything about wire mesh instead of fiber. I'll check that out.

Thanks for your help.
 
#15 ·
does whatever its wrapped in need wire mesh (like lath) around it? I havent seen anything about wire mesh instead of fiber. I'll check that out.

Thanks for your help.
you can use a number of different stuff, the reason you wrap the pipe is to separate it from the concrete, because concrete and plastic will grow and shrink (with tempeture changes) at different rates

the wire is not for the insulation but for the concrete, like rebar.
concrete by itself has no strength it need wire and / or steel inside to help stop cracking over time.

the foam, just wrap it with duct tape or what ever you have.
 
#16 ·
you're going to dick around w/foam/pvc pipe/etc so much you'll weaken the slab thru thinner thickness therefore strength,,, i'd use plastic tubing just as we've done on ' weeping walls ',,, then again, its YOUR ' tomestone ' & its only rocket science if you're building rockets,,, the difference 'tween expansion/contraction coefficients of concrete & plastic tubing is infinitesimal ',,, go have a beer, fergawdsake ! ! ! :laughing:
 
#17 ·
I wish I could give an accurite explanation, but I would be very careful with any tubing/pipe going thru the concrete. When the pipe enters perpendicular, it's not much of an issue. When it runs thru the length of the slab, or tombstone in this situation, it definately creates a weak point.

I've torn-out my fair share of concrete, & noticed that any entombed pipes always do more harm than good. In my situation, it's usually an old farm job where the farmer thought it would be advantageaous to throw some old crap pipe (or any random steel) laying around in the crete. Usually creates the wekest point of the whole slab.

In your application, I think I wold use a minimal steel pipe & weld a few light rebar directly around the pipe.

I would also look deeper into a counter top mix, as this may be your best chance for success. I have to give you credit, though, if this indeed your headstone. This very thought has crossed my mind many times. Luckily for me, that's as far as it ever went!
 
#18 · (Edited)
It will only be my headstone if my wife doesnt like it! thanks for the advice on the countertop mix.

Based on all of the above I am not running the pipe through the long run "up" the tombstone, I will run that on the outside. then the only pipe coming through the concrete will be the short outlet pipes through the 4 inches from "back" to "front".

Im still not clear on whether it would be better to actually embed the pipe in the concrete or to leave 3 holes in the concrete the size of the pipe (plus a bit of tolerance) and insert the pipe after curing, maybe with some silicone goop to keep it from shifting around/pulling out. Which is less likely to cause weakness? Also with the "hole" approach I suppose there is some chance of backflow seepage of water into the hole, which I presume is more likely to cause problems in the long run?
 
#19 ·
never saw anyone who wanted to take the hard route as much as you do,,, w/all your dickin' around w/pipe, you'd have been done 2 days ago using plastic tubing :( silicone'll stop any backflow,,, this is a much easier job that you're tryin' to make it imn-s-hfo :laughing: quit thinkin', postin', & DO ! ! !
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top