Thermally Enhanced Grout

Discussion in 'Vertical and Horizontal Loops' started by waterpirate, Apr 18, 2010.

  1. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Hows this for post.

    what is your experience with thermaly enhanced grouts? It is being touted as being cheaper than a 20% standard grout. It has been my experience that when you mix thermally enhanced grout to the manufacturers recommended sand content that you use the same amount of grout as not give or take a bag or two. You are simply making the volume of material needed to fill the bore more dense, not nessarily expanding its volume by any significant amount.

    In my world grout and drill fluid are the two most misunderstood processes involved in drilling, even by old timers. That being said if you mix and yield a single sack 20% grout properly you get a much better volume than if not, thus my statement.

    Now on to the real hot button. Even though the math supports the use of thermally enhanced grouts on an enginered project, it would be my premise that with out a conductivity test being done there is nothing to base the math on. So the reduction of footage based on the usage of enhanced grout for non engineered projects is a slippery slope regardless of what the software says.

    One other note on software. Unless you live in an area of extreme stratification of geology, the sub surface data that is entered into the software based on computer models from USGS test bores is wildly innacurate.

    What does all this mean? That you need to hire a local proffesional with a good track record and step back quietly from the software.

    Dean your input would be appreciated and also that of Geo Pro:D
    Last edited by a moderator: Apr 21, 2010
  2. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    Eric, good topic:D:D

    I am going to experiment with this on my next job.

    If it is true that adding sand doesn't increase the volume then you have a great point.

    I will grout some holes with no sand and others with sand and see how it works out.

    What do you mean here? Maybe I can learn something:):)

    We just mix it up and pump it down the hole. What should we be doing to "properly yield a sack of grout"?
  3. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    I switched to the so called single sack mix 3 years ago and never looked back. Because of it's nature, everything in one sack, it is critical that the recipe is followed exactly like baking. The recomended ph must be achieved or exceeded in make up water, the volume of liquid to pounds of product must be exact or slightly reduced. When the mixing begins it must be uniform and slightly grainy, to allow for further hydration throughout the proccess. Grout should be pumped under as low as pressure as possible and not to quickly. Typically I spend about six minutes pumping a 75 gallon batch. The grout at the end of the proccess is very different from the grout exiting the tank. I prefer wyo-ben over the other brands due to packaging and price. they pack 60 bags per pallet instead of baroids 48.
  4. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader


    Which wyo-ben product do you use? I went to their website and got lost.

    What brand of grout pump do you have?
  5. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    I use groutwell df. It has a solids content of 20% and conductivity of .45 I think. Soda ash is a must for this product, requiring a ph of 9 or better for good mixing and hydration rate. I am paying $8.50 a bag for a trailer load with $1,200 freight from middle america.

    We looked at all the grout machines available and wound up building. My machine uses the rigs 5x6 to mix and pump. My tub recirculates and has a counter spinning agitator in the bottom. Our other machine has two tubs so you can mix in one while pumping the other and uses a 4x5.

    We found the recirc as well as agitator really helps with uniform yielding and suspension of the sand.
  6. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    Eric, thanks for the info.

    Does Groutwell df contain sand?
  7. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader


    according to the Groutwell data sheet, one bag gives you 31 gallons of slurry.

    This is twice what I get out of one bag of Cetco grout and I am paying a lot more per bag,

    I owe you big time. Next time you are in Salt Lake, let me buy you lunch:D:D

    Do you add any polymer to your make up water?
  8. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    I am not familiar with cetco products, no distribution here? The beauty of the one sack from wyo-ben is you add nothing. Adjust the ph in your make up water and go. I soured very quickly having to deal with polymers that are an extra step, not shelf stable, need freeze protection, and they are expensive. nuff said. Baroid has a product simmilar but it is expensive and does not yeild out or gell as good as wyo ben.

    When I called wyo ben initially, they were quick to put me in touch with a local rep who pushed a pallet for free to try. The caviot was if you hate it no pay I will collect the left overs, if you like it you pay. That was hard to pass up, needless to say I loved it.

    That opened up the flood gate to their other products that speeded my drilling up some more. Stable polymers to fix a problem down hole on the fly, and wetting agents changed my mud program forever.:D

    Salt Lake City is a stretch for lunch, but it is on my bucket list of wonders of the USA.
  9. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader


    Do you test the water ph or just add some soda ash?

    Where do you eat out? Let me send you a gift card so you can take Mrs pirate to dinner.:D:D
  10. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    I tested the water from the supply well at the shop, it is the worst! I used a simple litmus paper deal I got from the local water conditioner guy. I then came up with the recipe. One two inch pvc cap of soda ash per 25 gallons of water gets me into the 9 to 11 range. I often buy water to fill the tanker if it is closer than the shop In the beginning I tested it only to find that it was not allways seven. The solution I came up with is that if you start at 7 and add the 2 inch capfull it has no harmfull effect on the grout only that ityields out really quick and your working time is reduced. So I got out of the water testing business on the premise my well water is the worst case scenario and just move a little faster if I start with better water. lol

    Thanks for the offer for me and Mrs. pirate but I am happy to share what I know with those who are willing to listen as a pre-payment for karma.

    Was the cetco product like baroids crap that you have to use the polymer to retard it to mix and pump? Did you get wildly different results based on the polymer? My biggest gripe about ez mud is that it seperates and you can not re-mix in the jug. That yields polymer for some batches, and the carrier fluid for others. This equals wildly differing results which usually netted driller throughing things and cursing.:mad:
  11. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    We only used the cetco grout granules that needed polymer for a short time.

    Then we switched to the cetco grout powder which does not need polymer, but cost 75% more.

    Which is why I am so happy with your help.

    With Groutwell, will there be a problem is the ph is higher than 10.

    I am just wondering how to best mix the soda ash. We get water from the jobsites which are all over the State. I am sure that there is big difference from site to site.
  12. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    I have probably mixed it as high as 15 and never had a problem except for it yields out quicker and you can not hold it as long. I have had it as thick as peanut butter in the tank and by just adding a little water it thins out to a pumpable mix. Even at its thickest it did not produce a mix that plugged up the works as with benseal or simmilar products.
    The ph is important to be high enough. The test strips that I used were cheap. I would get onsite and test the make up water. Then just add soda ash till it is high enough and move on. I stressed about the ph in the begining and now it is just another day. With a couple jobs under your belt you will know if the ph is not right just by the way the grout behaves.
    The product really has no bad behavior. If the ph is incorrect it just takes more product to fill te bore than if it is spot on or high.
  13. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader


    Thanks again.
  14. GCI

    GCI Member

    RE: grout

    Sorry Eric, a little late to the party but I thought I would comment on your original post:

    You are correct that in grouting, you are filling the bore and will require the same volume for a given hole size/depth regardless of whether you are using standard or thermally-enhanced grout (one gallon of bore volume is one gallon of bore volume). The reason thermally-enhanced grout is touted as being less expensive is due to bore length reduction (ie - hypothetical example: when a 200-ft hole with standard grout delivers the same performance as a 150-ft hole with a 0.88 (4:1) thermally-enhanced grout).

    20% mix recipe: 50-lbs bentonite and 24.0 gallons mix water will yield 26.7 gallons of slurry
    0.88 mix recipe: 50-lbs bentonite, 200 lbs of silica sand, and 17.5 gallons mix water will yield 29.3 gallons of slurry

    As you can see, the standard grout requires 50-lb of dry material to yield 26.7 gallons of grout slurry (20% solids) where the thermally-enhanced grout (0.88 mix) requires 250 lb of dry material to yield 29.3 gallons of grout slurry (63% solids). The delivered cost for standard (20% solids) grout is probably $0.40-$0.65/gallon, depending on location, distribution price, shipping, etc. The delivered cost for thermally-enhanced grout is probably $1.00-$1.30/gallon, again depending on a number of things. The decision to use thermally-enhanced grout or not should boil down to which loopfield is the cheapest to install while delivering the same performance (standard grout with more/deeper bores or thermally-enhanced grout with less/shallower bores).

    That being said, it's usually difficult for loop contractors to justify thermally-enhanced grout on a small residential project because you will need to haul much more material to the job site. That is exactly why grout manufacturers started producing thermally-enhanced grouts as one-sack premixed products as an alternative to the standard field-mixed products. The convenience comes at a premium though.

    Regarding your question on design accuracy, a reputable system designer should have a good grasp of the formation properties where the system is to be installed. As is the case with installation, a loop design is only as good as the designer. You can make software say just about anything you want it to say. Garbage in, garbage out is what I always say.

    I agree with you 100% that a good loop contractor with an equally good track record will have a grasp on what is needed in a given locale for most residential, light-commercial systems.
  15. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Thanks for chiming in Ryan. The misconceptions about thermaly enhanced grout are being espoused all over the web, and you are being hailed as the expert without being asked to comment, just paraphrased. That was one reason I started this thread. Being able to help Dwayne expand his grout knowledge and hopefully save some money in the process, priceles.
  16. GCI

    GCI Member

    RE: grout

    No problem Eric.

    To compare the cost of installing a loopfield with standard grout versus thermally-enhanced grout, you can build a spreadsheet similar to the calculator we have on our website (GeoPro, Inc. Bore Cost Comparison Calculator). This is an analysis that should be performed more often on commercial jobs. I have been seeing more and more designs calling out grout thermal conductivity values as high as 1.60 without having anyone understand the costs or even question why.
  17. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    As the geo wave continues to grow, I am experiencing exactly what Mr. Rawlings described in my new copy of geo outlook. The line between commercial and residential is getting muddier by the minute. You have commercial contractors trying to do residential and residential contractors trying to do commercial. Both situations are bad without getting a feel for the differances. I have said before that I also hate engineering lite. That is when a engineer cut and pastes crap off the internet, and or writes as typical all over the prints he drew on the back of a bar napkin. That is how a four ton residential job is done with an inside building loop for two compressor sections side by side, and an outside vault. And how a 40 ton commercial job turned out to be really only 33 tons after the conductivity testing was done, because the contractor was certain that the test well drilled by the water well contractor was the hole they paid for ?
    So as we all get busier the need for not so much a "value engineering" as much as a "reality gut check" by someone with some time served in geo.
  18. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Bad day Eric?

    Well said on the short engineering.

    My degree is in History, so I have a tough time teaching thermal dynamics and flow to guys that make or break our jobs. I took remedial algebra once upon a time in pursuit of a PE. I had taken four years of HS math and three at the college level. I opened the text book for the class and thought it was in Chinese. Wondering about my sanity at that point, my fifth grade daughter taught me how to read the book and do the math.

    I write directions well.

    I am in Massillon, Ohio retrofitting the spring job. The spring water ate pin holes in the refrigeration copper coils we put in the poly septic tank in less than four months. The horses up the hill drink the water and seem OK. It is hard to imagine that PEX Mark is installing HDPE instead of the copper.

    Eric hang tough we that know what we are doing will win in the end. Then we will fix the errors.


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