DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Concrete, Stone & Masonry (http://www.diychatroom.com/f105/)
-   -   Concrete Sealer Question (http://www.diychatroom.com/f105/concrete-sealer-question-183679/)

Jerry8C 07-15-2013 04:55 PM

Concrete Sealer Question
 
Concrete Sealer Question

A little over a year ago I had a new driveway installed using an aggregate surface. After having the concrete sealed, I noticed some white and light areas within a one to two week period. The contractor said to wait awhile which I did. When the areas did not improve the contractor returned and resealed the driveway. To the best of my knowledge he did all the prep work required and I think did his job okay. I do recall one of the workers seem to tell me that these light areas will always be a possibility.

In some spots the surface looks just like the original concrete without any sealer. It appears as if the concrete rejected the sealer. So, my question is why do I see these light or white areas and is that normal?

Thanks,
Jerry
7/15/13

stadry 07-15-2013 07:47 PM

i'm having trouble seeing your drivewway from my house,,, could it be that you forgot to post your geographic location ? or was it the pictures i couldn't see ?

off hand, it sounds as if there's efflorescence ( rising damp ),,, most sealers are breatheable & let moisture escape UNLESS it was applied too thick,,, .;003-.005" is about max for ea coat + it takes 2 coats

trying to think if we ever sealed exposed aggregate,,,,,,,,,,,,,,,,,,, nope, never did - not in 25 yrs ! ! !


Canarywood1 07-15-2013 09:14 PM

When applying the sealer to fresh concrete, they have to make sure all cement paste residue from the exposure process has been thoroughly removed to avoid sealing the milky-looking white paste on the surface,could this be what your seeing????

A picture may help.

stadry 07-15-2013 09:32 PM

'woody, its comin' back :laughing: how was the exposed aggregate surface achieved,,, 1, was a set retarder used ?; 2, did they use a ' roll-your-own ' retarder ( sugar/water ) ?; or 3, was graded coarse aggregate seeded into the floated surface ?

1 of the reasons we never sealed exposed agg conc :yes:

Canarywood1 07-15-2013 09:58 PM

Quote:

Originally Posted by itsreallyconc (Post 1216476)
'woody, its comin' back :laughing: how was the exposed aggregate surface achieved,,, 1, was a set retarder used ?; 2, did they use a ' roll-your-own ' retarder ( sugar/water ) ?; or 3, was graded coarse aggregate seeded into the floated surface ?

1 of the reasons we never sealed exposed agg conc :yes:


Not a question of how it was achieved, it's if all the paste was removed prior to sealing,if not it COULD be what he's seeing but maybe not,and where i'm from they always sealed exposed because of the deicers used in the winter,which i might add that you probably didn't have to contend with,that being one of the reason's you never sealed exposed,am i right???

stadry 07-16-2013 04:30 AM

only here for 15,,, don't recall we ever seal'd 'em up nawth,,, did use set retarders on some but most were sugar/wtr then press wshing next day,,, didn't see ' seeding ' til here

Canarywood1 07-16-2013 03:52 PM

Quote:

Originally Posted by itsreallyconc (Post 1216548)
only here for 15,,, don't recall we ever seal'd 'em up nawth,,, did use set retarders on some but most were sugar/wtr then press wshing next day,,, didn't see ' seeding ' til here


Where up nawth ya from,Chicago for me,and the guy's that did the McDonalds always sealed,and we used W.R.Grace exclusively for all chems. they used retarder for exposed and i didn't know of anyone that seeded.

stadry 07-16-2013 05:06 PM

upstate noo yawk but travel'd the e coast working mostly fed-funded a/p-air base projects + various state dot's,,, then spent 15yrs in the city - again, penndot, nysdot, city of ny, ct, & njdot stuff,,, never saw ' seeding ' til coming down he-ah + hilton head

Jerry8C 07-16-2013 05:35 PM

2 Attachment(s)
Thanks for all of the replies. I included pictures in this reply. I did not do so before because I did not think they would be clear enough. Anyway, I will try to answer some of the questions that were posted.

make sure all cement paste residue from the exposure process has been thoroughly removed to avoid sealing the milky-looking white paste on the surface,could this be what your seeing????

Yes, the contractor did what I would call a deglazing before applying a sealer.

'woody, its comin' back :laughing: how was the exposed aggregate surface achieved,,,


The aggregate was part of the concrete. After pouring the concrete, they removed the surface exposing the aggragate. Then they "deglazed" the surface and then sealed it. The deglazing was done with a spray and the sealer was rolled on.

With all the comments, I can see confusion by me as to what can be the problem. I thought about contacting the contractor, but I'm concern if he would return he would do the same process as he originally did and nothing would be solved. Also, I do remember him telling me I should not reseal too quickly as that can lead to problems, and I think he might have used the term "milky." So, if he were to consider resealing, I need to be mindful of that.

Jerry
7/16/13

Canarywood1 07-16-2013 07:07 PM

Quote:

Originally Posted by Jerry8C (Post 1216747)
Thanks for all of the replies. I included pictures in this reply. I did not do so before because I did not think they would be clear enough. Anyway, I will try to answer some of the questions that were posted.

make sure all cement paste residue from the exposure process has been thoroughly removed to avoid sealing the milky-looking white paste on the surface,could this be what your seeing????

Yes, the contractor did what I would call a deglazing before applying a sealer.

'woody, its comin' back :laughing: how was the exposed aggregate surface achieved,,,


The aggregate was part of the concrete. After pouring the concrete, they removed the surface exposing the aggragate. Then they "deglazed" the surface and then sealed it. The deglazing was done with a spray and the sealer was rolled on.

With all the comments, I can see confusion by me as to what can be the problem. I thought about contacting the contractor, but I'm concern if he would return he would do the same process as he originally did and nothing would be solved. Also, I do remember him telling me I should not reseal too quickly as that can lead to problems, and I think he might have used the term "milky." So, if he were to consider resealing, I need to be mindful of that.

Jerry
7/16/13



Well it looks like it's a cement related thing from the pic's, but not what i was thinking of,looks like a puddle that settled and all the cement was not washed away in the exposing process,but then thats only my opinion and i could be wrong,but i've never seen anything like that in my 35 years in the business.

Jerry8C 07-17-2013 04:42 PM

I made my inquiry on another forum and received an interesting reply which was:

“When you view the gray spots from an angle facing the sun, are they shiny like the rest of the surface or completely dull like unsealed concrete? If shiny, they have sealer on them but it's blushed (whitened). Buy a quart of xylol at a hardware or paint store and brush a little onto a gray spot. Stand back and let it dry about 10 minutes. The sealer should be clear again like the rest. You've simply re-melted the acrylic sealer with the xylene and released the entrapped moisture which caused the blushing.
Blushing usually occurs from applying sealer too thick.”

Would anyone have a comment if this is a good idea?
Jerry

stadry 07-17-2013 06:05 PM

makes sense to me but we use xylene

Canarywood1 07-17-2013 07:40 PM

Quote:

Originally Posted by Jerry8C (Post 1217148)
I made my inquiry on another forum and received an interesting reply which was:

“When you view the gray spots from an angle facing the sun, are they shiny like the rest of the surface or completely dull like unsealed concrete? If shiny, they have sealer on them but it's blushed (whitened). Buy a quart of xylol at a hardware or paint store and brush a little onto a gray spot. Stand back and let it dry about 10 minutes. The sealer should be clear again like the rest. You've simply re-melted the acrylic sealer with the xylene and released the entrapped moisture which caused the blushing.
Blushing usually occurs from applying sealer too thick.”

Would anyone have a comment if this is a good idea?
Jerry



The problem with that is did they use an acrylic sealer, i think i'd find out first if you can,as there are a ton of them out there,some sit on the surface ,some penetate and there are all kinds of bases,be careful using xylene once it's applied you cannot use anything else over it.

Pro Painter 07-17-2013 08:01 PM

Quote:

Originally Posted by Canarywood1 (Post 1217220)
The problem with that is did they use an acrylic sealer, i think i'd find out first if you can,as there are a ton of them out there,some sit on the surface ,some penetate and there are all kinds of bases,be careful using xylene once it's applied you cannot use anything else over it.


The xylene (or xylol, same thing) is a volatile solvent. When it has evaporated, it is gone. Whether or not anything else will stick over it depends on only two things: The nature of the resin that was left on the surface after the xylene evaporated, and the (chemical) formulation of the next thing that you might be putting on it.

The next thing you might want to put on it may be waterborne or solventborne, and there's a lot of different (resin) chemistries for what is even in a waterborne emulsion; some things might stick to the earlier resin residue and others might not.

If you don't know exactly what you started with, it's a real can of worms and sandblasting or grinding/polishing clean may be the only way to get from a surface that won't stay sealed, to be able to use a product that WILL work, applied on a clean concrete surface.

Jerry8C 07-19-2013 04:58 PM

Again, thanks to all who replied. I decided to call the original contractor and get his input. I told him two consistent comments I had received were the concrete was not cleaned properly and/or the sealer was put on too thick. Since he had resealed the driveway, he could understand the “too thick” as perhaps being the problem, although the problem was there before he resealed it. Anyway, without me telling him first, he said he would come out and use xylol and he described what it would do which agreed with the posts. So, at this point I will wait for his arrival and hope he finally solves the issue.
Thanks,
Jerry
7/19/13


All times are GMT -5. The time now is 10:24 AM.


Copyright © 2003-2014 Escalate Media LP. All Rights Reserved