# Help! Curing new concrete work



## MTN REMODEL LLC (Sep 11, 2010)

Clam bake.... I'm not a concrete contractor... but I think you are correct in keeping it moist for about 3 days... it's what I've always done. For finish work, and your slabs look nicely finished, I don't like a plastic visquine because it puddles water and can blothch the finish.

I like a permeable/ breathable moisture containment like you did...

We both know that concrete hydrates... not drys.

If there is something I don't know, I'd love to know. The slabs might have been fine with no misting, but I think you've just given them a better cure.


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## cleveman (Dec 17, 2011)

Whoever designed those step heights is a cruel bastard.

Nothing wrong with keeping it damp. You could just use a curing compound, bury it with dirt, or cover it with straw.


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## MTN REMODEL LLC (Sep 11, 2010)

cleveman said:


> Whoever designed those step heights is a cruel bastard.


Curiosity...?????


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## clambake6 (Sep 7, 2012)

MTN REMODEL LLC said:


> We both know that concrete hydrates... not drys.


Thanks MTN REMODEL LLC. Yeah, that's what has had me so freaked out. We poured when the temps were in the upper 70's, which was fine. 

Unfortunately, it jumped into the upper 90's the next day, and has stayed there since. I know the concrete doesn't cure through evaporation, but it needs to retain the moisture for proper hydration/cure. :yes: 

I was panicking because I thought the high temps, and a hot breeze, would suck the moisture out too fast without either a curing membrane of some kind, or water...

I hate to sound like such a chicken-little on this thing. The whole experience with the contractor was very professional: the site work was handled very well, the substrate and base were well compacted with a plate compactor, and it was wetted down before the pour. 

The forming was very accurate, for slope as well as riser heights with only about 1/16" difference. Lots of steel in the forms, overlapped, and well tied. Corners were square. The short retaining wall and planter are plumb, which was important to me because I'll be facing those parts with brick.

And the finish work was great; very nicely done. The crew worked very smoothly together.

I just remember enough about concrete from 30 years ago to be dangerous...to myself. It might have been better to have leaned on the contractor's years of experience when it came to watering the slab, but I panicked about the wind and heat. 

Thanks again for your post; it really sets my mind at ease.


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## clambake6 (Sep 7, 2012)

cleveman said:


> Whoever designed those step heights is a cruel bastard.


The riser heights are 4 3/4". I think the code for min./max. here is 4" and 7 3/4", so it's closer to the minimum.

The design mimics a wood and brick structure that was there before (I salvaged the brick to face the planter and retaining wall). It actually walks a lot more comfortably that it might appear. 

This was the old structure, built 22 years ago, and which had become unsafe:









I could have rebuilt everything with wood and the existing brick for a lot less money, but I'm 57 now and the maintenance needed in 10 or 15 years is going to be more than I want to do. hence, the concrete.


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## cleveman (Dec 17, 2011)

My preference is for no steps. If I can't have that, then I have standard (7 1/4") steps.


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## MTN REMODEL LLC (Sep 11, 2010)

*New version looks great*... and cut out the whining at 57.... YOU'RE YOUNG.:yes:


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## clambake6 (Sep 7, 2012)

MTN REMODEL LLC said:


> and cut out the whining at 57.... YOU'RE YOUNG.:yes:


Ahh, yeah... :laughing:

I'm actually still doing fine, and I'm about 1/4 way through a complete interior and landscape remodel. I could have done the form work for this part of the project but i didn't want to tackle that pour by myself.

I am sort of looking to the future with how I do things on the remodel. I spent a total of 35 years in the trades, 32 of them as a painter. I know that isn't nearly as much as some guys do but, between the damage diabetes has done to my feet, and ladder work has done to my knees and feet, I'm definitely giving some consideration to how much maintenance I want to do down the road.  

Thanks for the compliment on the work. I've had lots of compliments on the design. i'll post a couple pics when I get the brick facing on.


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## RWolff (Jan 27, 2013)

Every time I've poured concrete and after finishing the surface and waiting for the surface wetness to go away, I laid a sheet of poly plastic over it and weighted down the edges.
I would keep it watered down for 4-5 days, you need to cover the concrete with something because simply "misting" the surface the water misted on will evaporate in about 15 minutes and is all but useless in 90 degree heat.
Once the concrete has SET in a few hours or overnight, you can hose water it under the plastic sheeting a couple of times a day or so.

Not properly curing the concrete is probably the biggest reason the stuff chips, spalls easy, crumbles and cracks.
I have concrete I poured for my dog area that has zero cracks, spalls etc after about ten years in Iowa, because I mixed the concrete right, and i kept it wetted down with plastic on top for 4-5 days.


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## MTN REMODEL LLC (Sep 11, 2010)

RWolff said:


> Every time I've poured concrete and after finishing the surface and waiting for the surface wetness to go away, I laid a sheet of poly plastic over it and weighted down the edges.
> I would keep it watered down for 4-5 days, you need to cover the concrete with something because simply "misting" the surface the water misted on will evaporate in about 15 minutes and is all but useless in 90 degree heat.
> Once the concrete has SET in a few hours or overnight, you can hose water it under the plastic sheeting a couple of times a day or so.


Wolf...I agree with ya and I do the same on a garage or SOG that gets a flooring. Also, I'll do that after a day of set, but I've had trouble with "blotching" on a broomed or high finished surface from sorta the pooling of water under plastic. I've had the same problem with tiling and colored grout. 

Admitedly, ya sure gotta keep spraying it when it's low humidity (Colorado) and 90 degrees.


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## clambake6 (Sep 7, 2012)

RWolff said:


> ... i kept it wetted down with plastic on top for 4-5 days.


I laid the towels down after the concrete had set, and I've kept them soaked for the last three days (they seem to retain the water well). Do you think a couple more days with the same method will do the trick?


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## stadry (Jun 20, 2009)

curing agents & wet cures are fine & often times used when conc's placed but, in your instance, my $$'s on the contractor,,, bear in mind i've never placed stairs in my life :no: that's why i'm putting a long ramp beside our home :thumbsup: i do like the design of the steps, too - who's idea was that ? ? ? 

from what i read in your post, there's 2 good things about the curing process you chose: 1, it gave you something to do ; & 2, your bride gets to re-towel your home :thumbup:

IF the urge ever strikes you again, set up a lawn sprinkler :laughing:


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## stadry (Jun 20, 2009)

wolfie, going to bow to your expertise re CO conc but here in GA, we regularly place 9" & 16" conc w/no plastic/wet cure - just curing compound,,, biggest reason there's no random cracking ? proper timing & placement of JOINTS !

ft drum i( upstate NY ) was the 1st roller compacted conc job in north america,,, don't see conc out the back end of an asphalt spreader every day then watch a blacktop roller smooth it,,, we had lawn sprinklers set on stands for a 7d wet cure w/no plastic or curing compound,,, biggest reason no random crking ? proper timing/placement of JOINTS !

IF anyone's thinking wet cure, burlap or straw's best w/lawn sprinklers,,, plastic sheeting's for rain,,, imo, it often ruins the finish & discolors the conc


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## jomama45 (Nov 13, 2008)

Everything looks great to me, other than I "might" have sawn a few joints in the vertical walls/curbs. The steps should likely crack at the corner where the risers and treads come together, and are generally hardly visible, so a saw cut there often looks worse.

As for curing, you can't do much better than you have.......:thumbsup:

Leave the towels on for 3+ days, and make sure they stay wet. As soon as the concrete is allowed to dry on the surface, curing will no longer help. Many people think that you can simply "feed" the concrete a little water twice a day and that it's going to do some good, but as soon as it dries the first time, any additional watering is just a waste of time and water.

I generally avoid plastic as well, as it's likely to leave stains on the concrete for quite a while............


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## RWolff (Jan 27, 2013)

clambake6 said:


> I laid the towels down after the concrete had set, and I've kept them soaked for the last three days (they seem to retain the water well). Do you think a couple more days with the same method will do the trick?


That should be plenty of time, 3 days is ok, 4-5 is plenty, longer is even better if it's in an out of the way spot like a backyard patio and it doesn't matter if it's covered over with plastic or towels, but you'll be fine with 3-5 days.


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## clambake6 (Sep 7, 2012)

itsreallyconc said:


> ... i do like the design of the steps, too - who's idea was that ? ? ?


The idea was mine. I just reproduced in concrete a structure I built when we bought the place 22 years ago. 




itsreallyconc said:


> ...your bride gets to re-towel your home


Yup...as I was frantically raiding the linen closet for towels a voice from the other room was saying that it looked like a trip to Crate & Barrel was in our future.
Come to think of it...that voice sounded pretty happy...


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## Willie T (Jan 29, 2009)

Temperature is everything in curing. I used to do a lot of mil-spec work... (think 7 times normal cost)... and many of our slabs (some 5 feet deep with 8 to 10 layers of #8 steel in them) were required to have dozens of temperature recording heads poured into them, and the resulting story of the initial two-week curing time was recorded 24 hours a day on an automatic electronic graph.

If any of the temperatures were above the allowable limits, the slabs COULD be rejected..... and we would have to jack hammer them out, and start all over again.

Trust me... We DID NOT allow those temperatures to rise at all!


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## RWolff (Jan 27, 2013)

itsreallyconc said:


> wolfie, going to bow to your expertise re CO conc but here in GA, we regularly place 9" & 16" conc w/no plastic/wet cure - just curing compound,,, biggest reason there's no random cracking ? proper timing & placement of JOINTS !
> 
> IF anyone's thinking wet cure, burlap or straw's best w/lawn sprinklers,,, plastic sheeting's for rain,,, imo, it often ruins the finish & discolors the conc


Curing compound is a whole other ball of wax, Ive never used it.
Proper joints is good, though I have seen cracks between joints, just lousy concrete.
I would never use burlap or straw, those WILL leach out discoloring stains, but one the moisture is gone off the concrete and the surface is firm, laying *clear* plastic over it is not going to discolor it.

Joints don't prevent spalling, crumbling etc which is another whole issue, if the concrete doesnt cure properly it will be weak and spots that dried out too fast in the sun/wind, corners that were against bare wood forms etc arent going to cure right, and those will be the first to start crumbling or spalling.


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## jomama45 (Nov 13, 2008)

RWolff said:


> I would never use burlap or straw, those WILL leach out discoloring stains,
> 
> I've never seen it happen from either, and especially the burlap, which has been used for decades, if not more than a century with good results.....
> 
> but one the moisture is gone off the concrete and the surface is firm, laying *clear* plastic over it is not going to discolor it.


It happens all the time with clear poly. How much concrete have you poured and actually covered with poly?? :whistling2:


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## Willie T (Jan 29, 2009)

Visqueen usually messes up concrete. Something about the way it lays seems to transmit lines and marks.

All I've ever found Visqueen good for with concrete is for lining the inside of forms. If you stretch it tightly and smoothly, stapling it on the backside (outside), the resulting concrete pour will come out almost like you polished the concrete. It works beautifully on white concrete on exposed lintels.


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## RWolff (Jan 27, 2013)

jomama45 said:


> It happens all the time with clear poly. How much concrete have you poured and actually covered with poly??


Ive always covered all concrete with clear plastic- a clean new sheet not one that was hanging around in the shed or once used to tarp over a firewood pile. Just citing flat slabs not footings or foundations I did the entire floor in my 1000 sq ft house (it was all dirt before) and the dog yard is about 24' x 15', and "sidewalks" around the house, and I cast concrete sculptures which are bagged in black palstic garbage bags for several days to cure. I've never seen any discoloration from even those garbage bags on the concrete casts.

I've poured enough concrete and work with it enough to justify having bought an electric mixer, that doesn't make me a concrete slab guru but I'm no amateur.

I don't see how clear, uncolored plastic can discolor anything, there's no dyes, printing, soy ink or anything else on it to transfer to anything.
Using burlap or straw certainly does contain substances that can disolve and discolor, so can leaves, but leaf stains I've seen on concrete usually wash away after a bit.
Obviously if one lays plastic over concrete that still has a trowelable surface you are going to get some odd surface smooth/rough and lines in it, that's why one has to wait till the water is gone off the surface and the surface has set- several hours to the next morning wait, but contractors can't sit around for 6-8 hours nor will they come back the next morning.


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## stadry (Jun 20, 2009)

the only time we used plastic was hgwy paving & those rolls were 26' wide mounted on a powered cart which straddled the pour & followed the paver,,, thankfully we never had to use it often as its a pita to saw contraction jnts :furious: then the cart guys get all bent out of shape the next morning picking up all the 20' x 26'pcs & trying to reroll them  f 'em - they got paid to do just that :thumbup:

never saw a dot worry about plastic tracks, either :no:


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## jomama45 (Nov 13, 2008)

RWolff said:


> Ive always covered all concrete with clear plastic- a clean new sheet not one that was hanging around in the shed or once used to tarp over a firewood pile. Just citing flat slabs not footings or foundations I did the entire floor in my 1000 sq ft house (it was all dirt before) and the dog yard is about 24' x 15', and "sidewalks" around the house, and I cast concrete sculptures which are bagged in black palstic garbage bags for several days to cure. I've never seen any discoloration from even those garbage bags on the concrete casts.
> 
> I've poured enough concrete and work with it enough to justify having bought an electric mixer, that doesn't make me a concrete slab guru but I'm no amateur.
> 
> ...


Well if you've poured an entire 17 yards of concrete for yourself, then I'll have to step back and allow you to continue to offer your outstanding, highly experienced opine. You've obviously seen far more than I ever will, even though I've done this for a living for discriminating customers for more than 20 years................


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## RWolff (Jan 27, 2013)

jomama45 said:


> Well if you've poured an entire 17 yards of concrete for yourself, then I'll have to step back and allow you to continue to offer your outstanding, highly experienced opine.


Very good, I shall.




> You've obviously seen far more than I ever will, even though I've done this for a living for discriminating customers for more than 20 years................


The number of jobs or time spent making the same mistakes or carelessness because that's how it's always been done doesn't make something better though.
If you've gotten stains using poly and I have not, then obviously you are not doing it right and I must be, since I have never seen the stains on concrete I have poured.
There's things done at work that are wrong, but they don't change it because as someone is sure to say "We've always done it this way"


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## jomama45 (Nov 13, 2008)

RWolff said:


> Very good, I shall.
> 
> 
> The number of jobs or time spent making the same mistakes or carelessness because that's how it's always been done doesn't make something better though.
> ...


Yeah, you're right, just disregard the experiences of four other contractors in this very thread that have all witnessed issues from laying poly first hand........:whistling2:


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## stadry (Jun 20, 2009)

maybe i'm wrong - you think wolfie's waiting till the conc has taken its initial ' set ' while many other guys cover when there's still bleedwtr showing/puddling ? if i'm reading his posts correctly, 1 cy's a big pour so i'd have him in the ' artisan ' group rather'n flatwork/vert contracting


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## Oso954 (Jun 23, 2012)

> I don't see how clear, uncolored plastic can discolor anything,


http://indecorativeconcrete.com/?page_id=903


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## stadry (Jun 20, 2009)

another job for ' thinfinish ' :yes:


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## MTN REMODEL LLC (Sep 11, 2010)

I don't see how clear, uncolored plastic can discolor anything, 



Oso954 said:


> http://indecorativeconcrete.com/?page_id=903


Point well made Oso.... but I caution everyone to remember the quote:

"You can't believe everything you read on the internet'' George Washington / President


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## RWolff (Jan 27, 2013)

MTN REMODEL LLC said:


> I don't see how clear, uncolored plastic can discolor anything,
> 
> 
> 
> ...


I looked at that site, first of all it says:



> Many people who have observed this phenomenon think that the plastic has somehow “stained” the concrete. In reality, the concrete is not stained but simply cured unevenly.


It was called STAINS in this thread, and according to the above that's totally wrong, it's simply uneven CURING causing minor differences in the shade of the grey or white.

Of course one has to look at the whole picture, the web site claims, and who is behind the web site, are they trying to sell a "remedy" are they trying to oversell a service only THEY just happen to provide, these questions and more lend to the concept of checking the whole picture out and seeing where there is any conflict of interests going on, or product sales.

An example is going to a site that sells radon detection kits, well of course they will dramatize big time about how DANGEROUS and deadly your house is, complete with pictures of toddlers playing in the basement while grandma sits nearby almost smothered and breathing in the "deadly" CANCER causing radon fumes just gushing out of every little crack in the basement floor! but wait! the site has a solution for you, a guaranteed test kit for only $49.95... and what's more, they can send someone out to give you an estimate on a new basement floor and foundation walls.

It is not the clear plastic that is staining anything at all, it's the method, and the way that issue is eliminated is doing what I did:

Wait for the surface to set firm, hose the surface with water, lay the clear plastic sheet over the slab laying it completely FLAT with no air pockets, wrinkles or bubbles. Weight down the perimeter with clean sand all the way around. That plastic will stay flat and in contact with the concrete.
That was why I didn't have any issues, because I wasn't sloppy and let wrinkles and air pockets stay in the plastic sheeting. Obviously someone who gets lazy and leaves wrinkles in, is going to see some minor differences in finished tone, but good gawd!! is THIS how obsessive compulsive and anally retentive Americans have become now? that people actually get all upset and bent out of shape over such an insignificant, minor nothing of a thing like a little color differences on a freaking concrete sidewalk or driveway???

Wow, I'm just stunned when I read this level of obsession with stuff some people have, but I guess I shouldn't be real surprised since I work with a guy who has a diagnosed obsessive compulsive disorder, the kind that not one thing in his world is good enough to leave alone, no matter what it is he has to remake it half a dozen times before he is happier. Nothing anyone else does is any good. He complained about every machine or tool he ever bought, measuring with micrometer none were ever flat enough or straight enough or good enough and he'd demand a replacement.
One poor machine dealer had to replace a machine he bought THREE times, winding up throwing in a bunch of free stuff the last time, even then he wasn't happy and had to take the cast iron top and MILL it to his satisfaction.
If all people have to worry, obsess over and get pissed off about is a little blotcheyness on a concrete driveway, then there's something seriously wrong with them in my opinion.


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## RWolff (Jan 27, 2013)

Now for the pictures I mentioned I was going to take of the concrete work done by a contractor that failed within months. LOUSY site prep, lousy concrete, they finished the surface and left on a 90 degree sunny day.
The concrete dried off fast, here's what it did, that is a drain on the right where it slopes to. Note the control cuts they made with a carbide saw did absolutely nothing, the slabs cracked across the other way:


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## clambake6 (Sep 7, 2012)

RWolff said:


> LOUSY site prep...


Interesting...did they wet the substrate before they poured?

Trust me, I know about real OCD...not fun.


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## MTN REMODEL LLC (Sep 11, 2010)

RWolff said:


> I looked at that site, first of all it says:
> 
> 
> 
> ...


 
Wolfy... I've been here a short time... I've seen ya with great experience and recommendations... but let's just say we all have different experience...

Best

Peter


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## MTN REMODEL LLC (Sep 11, 2010)

clambake6 said:


> Interesting...did they wet the substrate before they poured?
> 
> Trust me, I know about real OCD...not fun.


Clambake... A persons technical concern ,or whatever your reference may be, is not OCD in my opinion... it's just wanting to do it right.

Is your clamback name from the east coast, specifically the cape?


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## stadry (Jun 20, 2009)

MTN REMODEL LLC, YOU are exactly the kind of guy who spreads disharmony & disinformation in this forum :furious: it wasn't george washington who said that,,, rather it WAS abe lincoln who said it ! :laughing:


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## Willie T (Jan 29, 2009)

Depends upon for whom you're building. I've had to change out countertops because the buyer didn't think the marbling grains were close enough to matching each other in four or five individual pieces of countertop.... some 15 feet from the others.


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## TheEplumber (Jul 20, 2010)

Never ceases to amaze me how threads keep going and going......
Why don't you give it a rest- you guys are OCD about posting....


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## MTN REMODEL LLC (Sep 11, 2010)

itsreallyconc said:


> MTN REMODEL LLC, YOU are exactly the kind of guy who spreads disharmony & disinformation in this forum :furious: it wasn't george washington who said that,,, rather it WAS abe lincoln who said it ! :laughing:


To : IT AINT CEMENT: Hezuz... That's spanish for Jesus... You apparently don' t know historically your ass (that's a barnyard animal) from a ditch (that's a hole in the ground).

When George Washington was wet and tired from paddling across the Potomic with Abraham Lincoln while Abe was imbiding with John Wilkes Booth, there developed an unfriedly relationship.. and subsequently at the battle of Gettysburg when Abe Lincoln arose from his bunker and saw his shadow (and we had 6 more months or winter) he bequethed and forever transfered his favorite quotes to George.

So there...


Best Bubbi...

Peter


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## MTN REMODEL LLC (Sep 11, 2010)

TheEplumber said:


> Never ceases to amaze me how threads keep going and going......
> Why don't you give it a rest- you guys are OCD about posting....


Just joking... but you're probably correct


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## clambake6 (Sep 7, 2012)

MTN REMODEL LLC said:


> A persons technical concern ,or whatever your reference may be, is not OCD in my opinion... it's just wanting to do it right.


Oh, I agree. Making two round trip drives back-to-back (without any sleep in between) between the SF Bay Area and LA because you're sure the paint is failing on a house you *just painted* is what I consider an expression of real OCD. And anxiety disorder.

Not that I actually know anything about something like that first hand...


The clambake6 moniker just popped into my head when I signed up.


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## jomama45 (Nov 13, 2008)

RWolff said:


> If all people have to worry, obsess over and get pissed off about is a little blotcheyness on a concrete driveway, then there's something seriously wrong with them in my opinion.



Even if there's something wrong with them, they still go by the name of "customer who pays the bill" if you're a contractor. What may pass as marginal finishes as a homeowner can be 180 degrees from what's acceptable as a contractor who's in the business of collecting his money....................


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## MTN REMODEL LLC (Sep 11, 2010)

clambake6 said:


> Oh, I agree. *Making two round trip drives back-to-back (without any sleep in between) between the SF Bay Area and LA because *you're sure the paint is failing on a house you *just painted* is what I consider an expression of real OCD. And anxiety disorder.
> 
> Not that I actually know anything about something like that first hand...
> 
> ...


Heck... That trip, from Dana Point to Tiburon (my kids) is not OCD, it's f'n he)).

Love your Cali weather and your Cali people... so who the heck elects your politicians? 

(I think the original question has been overwhelmingly answered.... just kidding around now)

Best


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## RWolff (Jan 27, 2013)

clambake6 said:


> Interesting...did they wet the substrate before they poured?



As I remember, the ground was WET from heavy rains, this was a gravel driveway in the alley, I think they brought in some more gravel to give it a slope, and then poured.



> Trust me, I know about real OCD...not fun.


No fun for those who get their work, everything they do micro-managed and criticized by said co-worker with it!


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## MTN REMODEL LLC (Sep 11, 2010)

jomama45 said:


> Even if there's something wrong with them, they still go by the name of "customer who pays the bill" if you're a contractor. What may pass as marginal finishes as a homeowner can be 180 degrees from what's acceptable as a contractor who's in the business of collecting his money....................


BTW Yomama... You're the only one making sense and any good points... are you OCD.

Best


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## RWolff (Jan 27, 2013)

MTN REMODEL LLC said:


> Just joking... but you're probably correct



We LIKE posting 




> Wolfy... I've been here a short time... I've seen ya with great experience and recommendations... but let's just say we all have different experience...
> 
> Best
> Peter


Aye, we do Peter thanks!




> Depends upon for whom you're building. I've had to change out countertops because the buyer didn't think the marbling grains were close enough to matching each other in four or five individual pieces of countertop.... some 15 feet from the others.


I can't help but think of the day that person either develops a health problem or has a family member who does, and given 6 months to live, how they'll look back on the frivolity and wasted time of obsessing over unimportant things like that!


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## MTN REMODEL LLC (Sep 11, 2010)

RWolff said:


> We LIKE posting
> 
> 
> 
> ...


More serious note...:thumbsup::thumbsup::thumbsup::yes::yes::yes:


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