Spots on stamped concrete

Closed Thread

  #1  
Old 03-01-13, 02:10 PM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
Spots on stamped concrete

Quick question. I noticed after all the snow is gone and we got all that rain I noticed some white spots on the stamped concrete. Looks like these spots went through the seal. Any clue what their from or a fix?
 
Sponsored Links
  #2  
Old 03-01-13, 02:15 PM
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 45,391
Likes Received: 34
Is your concrete good and dry? I'm not real familiar with the sealer used for stamped concrete but know that some waterbased products turn milky when wet but clear up when dry.
 
  #3  
Old 03-01-13, 02:45 PM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
It poured all night so not completely dry.
 
  #4  
Old 03-02-13, 07:10 AM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
I'm pretty sure it's hard water stains. I didn't realize rain could do this. I guess I have to visit Home Depot for a concrete cleaner?
 
  #5  
Old 03-02-13, 09:17 AM
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 45,391
Likes Received: 34
I don't know We have some members that know a good bit about stamped concrete and their care - hopefully they'll have time to chime in later with better advice for you
 
  #6  
Old 03-02-13, 09:23 AM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
Ill post pics later. To me it looked like these white droplet marks go right through the seal.
 
  #7  
Old 03-02-13, 01:05 PM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
  #8  
Old 03-02-13, 01:08 PM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
  #9  
Old 03-03-13, 05:49 AM
Member
Join Date: Feb 2005
Location: USA
Posts: 1,396
I've stamped concrete for about 20 years. It looks like your sealer is blushing (whitening or hazing) and delaminating slightly. Blushing is caused by moisture being trapped under the sealer and lifting it just a bit above the concrete surface. It's similar to the way badly tinted car windows look when they've got bubbles under them.
Blushing is extremely common and an easy fix. Get some xylol (a solvent) from home depot, an empty 5 gallon bucket and a natural bristle brush or broom. Because of the size of the affected area, I'd suggest an acid brush on a broom handle and make sure it's not poly bristles, they may melt with xylol.
Dip the brush in the xylol and scrub it around on the spots. They will disappear. This is because the xylol has remelted the acrylic sealer and stuck it against the surface again. The xylol will dry very quickly, and when it does the concrete will appear freshly sealed and look like new. If your stamped concrete is usually slippery when wet, this would be a good opportunity to add just a bit of shark grip (powdered non-slip additive from Sherwin Williams) to the xylol in the pail before you scrub it in. It won't take much.
Before you do the whole patio, do a small test spot with a chip brush to make sure the discolored spots are indeed blushed sealer.

Good luck!
 
  #10  
Old 03-03-13, 07:12 AM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
Thank you very much. I will try this. The moisture makes sense because where I notice flaking mostly is where water would sit and cover the walkway like a pool of water. Ill try a small area. Can I wait a month till spring to do it or sooner the better? It's cold now here.
 
  #11  
Old 03-03-13, 06:46 PM
Member
Join Date: Feb 2005
Location: USA
Posts: 1,396
Wait until it's warmer. There's no hurry
 
  #12  
Old 03-09-13, 10:45 AM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
Just wanted to add a few things. We just got more snow again and it's beginning to melt. I am seeing more spots but wondering if its not really blushing. Is it possible that its the seal chipping. All these spots look like chipped seal everywhere that exposes the bare cement. I even have a slab of stairs they they refinished with stamp and seal. The stairs are like 3 feet off the ground level and there's no way water is coming up from under those stairs. And on top of the stairs there are new chips in the seal. The only thing I do is shovel the snow off the walkway and I'm very careful with the shovel.
 
  #13  
Old 03-09-13, 12:29 PM
BridgeMan45's Avatar
Member
Join Date: Oct 2011
Location: USA
Posts: 3,196
I may be wrong, but the pix look like the concrete surface is delaminating, as opposed to just a sealer problem. Unfortunately, there is no quick cure for such a defect, and it will continue to get worse. Over-working fresh concrete, or baptizing the surface with excess water during finishing, are common causes of delamination, bringing too many fines to the surface and compromising its strength by sending the water-cement ratio out of sight.
 
  #14  
Old 03-09-13, 01:06 PM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
Well when I use my fingernail on a spot the seal scratches off. When the walkway is wet you can't even notice.
 
  #15  
Old 03-09-13, 02:19 PM
BridgeMan45's Avatar
Member
Join Date: Oct 2011
Location: USA
Posts: 3,196
Then you're saying there is absolutely no flaking or peeling of mortar, anywhere on the surface? The sharp lines/shadows in the photos show what looks like classic delaminated/debonded concrete. But it wouldn't be the first time my eyesight fooled me, so I hope you can fix the problem with nothing more than additional sealant (when things warm up and dry out). Just make sure nothing flakes off if you lightly tap it with a pointed hammer, which good concrete can easily resist. Another test would be to drag a heavy chain over the entire surface, in multiple passes. If the concrete is not delaminated, the noise from the chain will be quite uniform and higher-pitched.
 
  #16  
Old 03-09-13, 03:17 PM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
close ups

Here are some close ups. You can see that on 2 of the photos (1st and 3rd link)labeled stairs you can really see the chips. I guess the question is how do they get the color of this walkway black and gray? Is it concrete thats colored? I appreciate the help. Either way ill be calling the contractor who did the job. It was just installed this summer.
http://i286.photobucket.com/albums/l...ps6a013aa8.jpg
http://i286.photobucket.com/albums/l...ps23faa4fa.jpg
http://i286.photobucket.com/albums/l...psd7f059dd.jpg
http://i286.photobucket.com/albums/l...ps84a206f1.jpg
http://i286.photobucket.com/albums/l...pse033a478.jpg
http://i286.photobucket.com/albums/l...psd110298e.jpg
http://i286.photobucket.com/albums/l...ps963dc091.jpg
 
  #17  
Old 03-09-13, 07:01 PM
BridgeMan45's Avatar
Member
Join Date: Oct 2011
Location: USA
Posts: 3,196
As long as every location passes the previous tests I suggested (lightly tapping with a pick hammer, or chain dragging), you should be all right. I'd be inclined to ask that the entire surface be resealed, as opposed to just a dab-and-smear job with liquid sealant wherever there's a white spot. Regarding the color differences, it almost looks like powdered dye was floated into the surface where it's definitely darker. The more uniform gray areas with isolated depressions look as if they broadcast rock salt in at sporadic locations, to give it a distresed look when the salt dissolved and washed away.

Guess I'm glad to be approaching full retirement status, because I could have sworn that I saw (and still see) obvious evidence of numerous delaminations and surface fractures. Time for me to throw in the towel and let the youngsters take over.
 
  #18  
Old 03-10-13, 12:56 PM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
Thanks for all the replies. I'm gonna call the guy who did the work. I took some water and dropped it over the places that are flaking. The water turn beads like its supposed to but around the spots flaking get absorbed.
 
  #19  
Old 03-11-13, 07:21 AM
Member
Join Date: Feb 2005
Location: USA
Posts: 1,396
Several things going on here. First is blushing. When I said water coming up through the concrete, I was not speaking of hydrostatic pressure. I meant water vapor. Moisture gets into concrete in a lot of ways, from seeping through the joints to wicking in from the sides or underneath. Then it tries to evaporate out. If it's trapped by impermeable sealer, it can't evaporate. Therefore it is trapped, freezes, and debonds the sealer. That's why you can scratch it off with your nail. It's also why it's coming off with the shovel (as evidenced by the light colored straight lines)
I wrote a detailed article about this, but the forum moderators don't like me posting my website's URL here, even if I'm not trying to sell you anything.
Another thing going on is that they left too much antiquing release (the black stuff) on the surface prior to sealing it. I've got an article about that too.
Anyway, The problems can be somewhat taken care of with the xylol as I described above. But by all means call the contractor back.
 
  #20  
Old 03-11-13, 11:36 AM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
Pecos, thanks for the reply.
I contacted the contractor. He hasn't looked at it yet but he said this happens usually the first year from the snow sitting on it. He said exactly what you recommended. He is going to stop in when it gets warmer with Xylene and spray.
 
  #21  
Old 04-21-13, 06:56 AM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
Question

I appreciate everyone's help. One other question. This pic is from the stairs. It was originally a cement slab stairs. They refinished it and stamped. It appears as you can see that it is peeling right off. Not the concrete but the seal. Do you think xylene will fix this? http://i286.photobucket.com/albums/l...psd7f059dd.jpg
 
  #22  
Old 04-21-13, 01:17 PM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
Xylene test

So I tried a few of the spots on the walkway with xylene. I'm pretty posses that it didn't fix the problem. The spots just turned dark brown color as u can see. I'm guessing it may be a delaminating problem? http://i286.photobucket.com/albums/l...ps80299b07.jpg
http://i286.photobucket.com/albums/l...ps8f4e1692.jpg
http://i286.photobucket.com/albums/l...ps4690490e.jpg
 
  #23  
Old 04-23-13, 09:22 AM
Member
Join Date: Feb 2005
Location: USA
Posts: 1,396
Wait...is this stamped concrete, or a stamped concrete overlay? Stamped concrete is freshly poured, full depth concrete from scratch. A stamped concrete overlay is applied thinly over existing concrete. Totally different thing.
 
  #24  
Old 04-23-13, 10:33 AM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
The whole thread is about stamped concrete. The walkway is actual stamped concrete. The stairs are overlay. Contractor came back to look at it. Said it was a moisture issue. He had put 3 coats of sealer on it. I asked if it was because he sealed it before cement was cured but he said that shouldn't matter it's a curable sealer. He is going to fix it. I did try putting a small area w xylene via a brush but it didn't do anything. He said you have to apply the xylene, wait 10 mins then back roll.
 
  #25  
Old 04-23-13, 10:39 AM
Member
Join Date: Feb 2005
Location: USA
Posts: 1,396
After 10 minutes the xylene will have long ago evaporated and the sealer would be dry and hard again. No amount of backrolling would help at that point. When you applied xylene with the brush, did you scrub it around or did you just brush it on?
Ask what the sealer he used originally was. I've seen guys apply sealer the day following the pour instead of using an actual cure and seal. Cure and seals can breathe whereas sealers cannot. One company I dealt with had been applying a very good quality, high-build sealer to their concrete on the day following stamping. All their jobs turned cloudy if not outright white within just a few weeks. I found out that the sealer they were using was a sealer, not a cure and seal. This particular sealer was extremely resistant to xylene and would not re-wet. All of it had to be chemically stripped off. I hope for your sake that this is not the brand your guy uses.
 
  #26  
Old 04-23-13, 10:48 AM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
I used the xylene on the walkway. I just put it on a little natural bristle paint brush. I didn't scrub just brushed it on n nothing happened.
You are right the stairs did flake off. The contractor said remember when we were doing the stairs it kept raining as they were doing it n the tried overlaying 3 times ( not my problem). He is coming back to fix it all.
I wanted to do a patio in the back but don't want the same issue and its so slippery when wet. He said he put some non slip on the the walk way but said the sealers these days are junk.
 
  #27  
Old 04-23-13, 10:54 AM
Member
Join Date: Feb 2005
Location: USA
Posts: 1,396
I think we were posting at the same time. I edited and added to my last post, so please read that info.
The sealers "these days" are no worse than in the past.
You may private message me for more details. Don't want to air dirty laundry on the forum.
 
  #28  
Old 04-23-13, 12:47 PM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
He said it was a cure n seal. Diamond clear?
 
  #29  
Old 04-23-13, 01:57 PM
Member
Join Date: Feb 2005
Location: USA
Posts: 1,396
Yes, that should be fine, except for the 3 coats. Probably just too thick.
 
  #30  
Old 04-23-13, 02:22 PM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
Thanks for all the help. He had said he's gonna xylene the whole thing then seal it again. If I do a patio u think 2 coats instead of 3?
 
  #31  
Old 04-24-13, 10:19 AM
Member
Join Date: Feb 2005
Location: USA
Posts: 1,396
Two very thin coats are recommended. As I said, applying too thick causes a lot of problems. For the same reason, I would try to fix your stamped concrete with a xylene scrub (not spray and backroll), and not add another layer of sealer. But if your contractor wants to do it, he's seen it in person and I haven't. It's his work after all.
 
  #32  
Old 04-24-13, 11:16 AM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
Thanks. With the patio ill ask for 2 thin coats. With the xylene on the walkway I should dip a natural bristle broom in xylene and really scrub hard? Before I didn't scrub at all just painted it on and it did nothing. Ill try it again but if I pour plAin water on these spots they soak up the water like a sponge meaning the sealer is completely gone in those flaked spots.
 

Last edited by moreira85; 04-24-13 at 01:21 PM.
  #33  
Old 04-24-13, 03:07 PM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
I tried scrubbing pretty hard with a rag since I don't have a broom yet. Barely any change.
 
  #34  
Old 04-25-13, 07:30 AM
Member
Join Date: Feb 2005
Location: USA
Posts: 1,396
Interesting. Xylene usually melts Super Diamond Clear sealer instantly. If applied water very quickly soaks in, then you are correct that there is no sealer on those spots.
If the sealer was water based instead of solvent based, it may be more resistant to xylene. Was the sealer clear with a strong odor and come in a metal pail, or was it milky with a very mild odor in a plastic pail? Metal pail/odor equals solvent based.
 
  #35  
Old 04-25-13, 10:34 AM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
I didn't seal it they did. I don't remember the color of the bucket. I do know there is definitely no sealer on these spots. The water soaks in fast. The nice gray color is gone and all you see is the bare concrete color.
 
  #36  
Old 05-11-13, 09:47 AM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
Here's the update. They came back to fix it. Xylene the whole thing and it didn touch it. Looks as though the sealer flaked off n took the color of the concrete from the release with it. They coated the whole walkway with release powder to get these spots colored then will reseal. They did one little section and it looks good. The contractor says he's been doing it 12 years and supposedly never saw this.
 

Last edited by moreira85; 05-11-13 at 11:52 AM.
  #37  
Old 05-14-13, 07:16 PM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
Problems all fixed. They had to stip all the sealer and re-antique the color then reseal.
 
  #38  
Old 08-26-13, 06:02 AM
Member
Join Date: Aug 2013
Location: USA
Posts: 3
Stains in recent patio pour

I really need someones advice, I just recently had a pour done and it was a rainy day, my gutter was dripping onto the fresh pour and the concrete company put a rubber mat where the drip was and told me to leave it there until the next day. The area seems as if it never fully cured where the rubber mat was and even has water drip stains. It has been about a month since the pour and I am hoping with sun this will cure to look like the rest of the patio, but any advice would be greatly appreciated. Here is a picture of the stain:

http://www.internetsolutionsforless....ages/stain.jpg
 
  #39  
Old 04-05-14, 09:21 PM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
Of course after this brutal winter I have the problem again. It looks great when it's wet from rain. I also had a patio installed last summer and the same thing happened to it. Seems as though there are light colored spots from the antiquing actually flaking off. Looks terrible. Is there a way to reantique? I was wondering if I could just pressure wash and reseal wiith solvent sealer/antiquing agent and xylene mixed in?
 
  #40  
Old 09-13-14, 06:44 PM
Member
Thread Starter
Join Date: Dec 2008
Location: Mass
Posts: 310
Just closing out this thread. I power washed, got a good sealer and looks and been holding up perfect. The spots are all gone. Looks brand new.
 
Closed Thread

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes