Flowable Fill

[cgland]

Has anyone really gotten into using FF on a regular basis? How do you find the numbers looking compared to traditional modified infill?

Chris

[Mbella]

For those that isntalled flowable fill a year, or more ago, any problems with settlement?

[mckeeland]

we do one or two patios a year know with it for the past 3 years. i have not had any issues with it so far. for use stone just keeps getting more expensive every couple of months. the cost on larger projects always come out to be the same or a little less. when we are busy it is great to get in and get out. maybe in slower times i would just use modified and lifts to keep the guys and busy and put a little more in my pocket. the piece of mind is what i like the most. you get 100% compaction everywhere the FF goes, even in tight corners.

[cgland]

McKee - Do you mind posting some pics of your FF jobs for some of the members to see? Thanks in advance.

Chris

[mckeeland]

here are a few

[mckeeland]

a few more

[mckeeland]

a few more

[scaper27]

I have heard of it beofre, but never played with it. Thats basically whats supposed to be used by pools and thats it right

[mckeeland]

flow fill can be used anywhere that compactable fill is used. it is used a lot when they need to install utility lines though a street and need fast, settle free back fill. the major use for us is on raised patios and difficult to compact applications. you still need at least a 6" aggregate base to lay the pavers on.

[lawnkid]

Is there any geotextile required in a flowable fill application? Once under the fill to seperate the fill from the soil and once again on top before compacting 6" of modified? Or do you not use any at all?

[mckeeland]

as far as i am aware, it is not required under the flowfill. we put it under the 6" of base stone, more to separate the stone and bedding sand from the gaps in the wall and as a safety precaution.

[Grn Mtn]

when you order your fill, what are you asking for? I know it can be made from many different types of material and it can have very different psi properties.

why do you feel you still need 6" of base material? why not just your bedding sand?

thanks for the picts.

[Colonial]

Nice Mckee,

do you have any sepage through the wall from the flowable? if so do you just clean it up as you go, or is there another solution.

Thanks,

[STLPONDS]

I was under the impression that you bring it to your desired base height than put your bedding sand down.

How long before you can set pavers?

[CaptainsLS]

why do you feel you still need 6" of base material? why not just your bedding sand?

I'm interested in this as well. I remember asking you if material bleeds through the face of the wall on LS, and you said it didn’t. There was no source for FF up until this year in my area. I see your guy sinking into the fill, how long before this stuff "cures"

[Colonial]

I'll tell you what though if this stuff works as good as I have heard fro some, and the questions get asked, we may start using it. The cost benefits wont matter too much because it comes out to about the same as the guys tapping and running it in on a "normal" job, but imagine the time saved where you could be moving on to another job.

[mckeeland]

from everything that i was taught you still need the 6" of base materials, the flow fill is acting as virgin soil, but not as the base. also it would be hard to get the flow fill to pitch the way you want and finish to the height that you need it to.

i have had very little seepage through the wall and when we do it hoses off or rubs off after it dries.

[cgland]

Not only that, the 6" of stone acts as a buffer between the FF and the paver/sand, thus eliminating the concrete wicking into the pavers causing excessive efflo.

Chris

[STLPONDS]

I know this is still in the experimental stages,but why can't it only be 2"-3" of base. I'm just asking on this since I have no experience with FF or concrete's seeping properties etc. The labor time is the exciting factor using FF.

[cgland]

On larger projects it's hard to get your pitch w/ only 2-3" of stone. FF is self leveling (for the most part) so if you have say 3" of stone at the house and you need to go 20' at 1/4" pitch you would be digging into the FF to set your grade.

Chris

[Colonial]

In any case, 6" of base on FF is better then tamping lifts up to 2'-2.5'.

[mckeeland]

Here is a article in ICPI about flow fill. I believe the patio in the pics is one of the first raised patios with flowfill in are area. It was an EP Henry project.

http://www.icpi.org/myproject/07%20May%20Contractor%20Focus.pdf

[Colonial]

Thanks Mckee

[Evening Star Lighting]

I see your wall is Geogrided. It appears the length is about 4-5' in your photos. Since your using Flow-Fill, could you reduce the length to about a foot? It would still be anchored in the cement, but probably easier to trowel the stuff around.

[custom patios]

i have a concern with the f.f. process. its a fairly new technique and may take a few years to show any problems, if any. mckee, my concern is that the concrete expands and contracts. it also exerts alot of force on the adjacent structures while curing. when you do a large pour it is wise to install expansion joints for this purpose. have you noticed any push on the walls or other structures since you have been using f.f.. i read about the process thru e.p. henry, but i dont trust them at all. seems like a decent way to save some time. maybe im just overly concerned. what are your thoughts.
steveo

[Grn Mtn]

i have a concern with the f.f. process. its a fairly new technique and may take a few years to show any problems, if any. mckee, my concern is that the concrete expands and contracts. it also exerts alot of force on the adjacent structures while curing. when you do a large pour it is wise to install expansion joints for this purpose. have you noticed any push on the walls or other structures since you have been using f.f.. i read about the process thru e.p. henry, but i dont trust them at all. seems like a decent way to save some time. maybe im just overly concerned. what are your thoughts.
steveo

FlowableFill is not new and it is not concrete, mostly wet sand. here is a great link for you to read....http://www.flowablefill.org/performance.htm

[mckeeland]

i have a concern with the f.f. process. its a fairly new technique and may take a few years to show any problems, if any. mckee, my concern is that the concrete expands and contracts. it also exerts alot of force on the adjacent structures while curing. when you do a large pour it is wise to install expansion joints for this purpose. have you noticed any push on the walls or other structures since you have been using f.f.. i read about the process thru e.p. henry, but i dont trust them at all. seems like a decent way to save some time. maybe im just overly concerned. what are your thoughts.
steveo


like grn mtn said, its not really concrete. its density is more like virgin soils, or a hard dry clay soil. it can still be dug with pick axe after it cures. i have not encountered any problems with it so far and we have been installing it for about 3 years.

as far as the geo, i dont know? i do know now its advised to pour it up to your geo grid layer let it set up, lay ur grid down on to it, then pour your to the finish height or next grid layer. this makes sure ur grid stays flat and perpendicular to your wall.

[custom patios]

well then, that explains that. thanks for the info.

[Grn Mtn]

well then, that explains that. thanks for the info.:lol:

the article mentioned that because of bouency concerns of pipes and stuff you need to tie stuff down prior to pour.

[mckeeland]

:lol:

the article mentioned that because of bouency concerns of pipes and stuff you need to tie stuff down prior to pour.


i learned that the hard way. we did waterline at a commercial building and 100' of it went across the concrete driveway. so i decided to back fill the parking lot area with the flow fill to insure that it didnt settle. well the plumber at the last minute decided to put the 1-1/2" sch 40 into 3" abs sleeve leaving a 1-1/2" air space. man did that sucker want to float. that was a real nightmare but we managed to secure it down and get it done.

[JFMX345]

Is there potential to mix smaller amounts of FF on site? Is it mixed the same as concrete?
I know that the components are similar (ash,sand,concrete) but I'm not familiar with the mixing process.

[mckeeland]

mixing process is the same except they put an admix to increase flow-ability prior to pouring.

[JZap]

McKee I remember you showing this on Lawnsite and mentioning this before, but if you're doing 18" lifts and need multiple pours, typically how many pours can you do in a day? And also I vaguely remember you mentioning a lot of water loss as it cures?

[mckeeland]

usually you build up to your first grid layer, pour, then continue building to the next grid layer. when you reach it you pour again. i dont know if you can pour multiple layers in a day. 24" at a time is alot. we did it the first time we used it and it was fine, but i would not do it again.

you definitely see alot of water come to the top, alot in comparison to regular concrete that is. there is no problem with the water loss though.

[JZap]

I've never used FF, but we've been talking about it for the last year. I'm hesitant to experiment at a customers house. The article you linked to said they have 18" lifts in pours. I remember you saying you've done 24", but wouldn't do it again? I also remember you getting hammered with similar threads int he past haha. Maybe you should be a FF spokesperson on the side?

[mckeeland]

you would think i got kick backs from the ready mix plants or something. LOL

everybody loves to ask questions about it, but are afraid to use it. once you do it you will love it. my first pour was under the recommendation of my EP Henry conserv rep. i dont think i would have done it with out him holding my hand. he was big help. now its no big deal.

i have had alot of experience with pouring concrete in the past, so that makes it a little easier. having a concrete truck pull up to your job can freak the best of us out, especially when you have 3 of them there because they screwed their timing up.:scared:

John i think you are a little far from me, but if you ever did a job close to my area i would be more than happy to give you a hand on a flow fill pour.

[JZap]

Allied and Murwin Concrete would show as well I'm sure. But I might take you up on that if we work in NJ again soon. We've been doing a lot of job for Westrum Builders in NJ.
What tools do you need to spread? Rakes, floats or both?

[mckeeland]

coma-longs are all you really need and a shovel or two and knee high boots or better. maybe even hip waders if you do 24" at a shot LOL.