DIY Home Improvement, Remodeling & Repair Forum > DIY Home Improvement > Bricks, Masonry and Concrete > Odd concrete stain- simple fix or a nightmare in the making?




Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old 06-30-2014, 07:37 PM  
CarolinaMom
Junior Member
 
Join Date: Jun 2014
Location: Charlotte, NC
Posts: 5
Default Odd concrete stain- simple fix or a nightmare in the making?

We moved into this house about 6 years ago. It is on the main road in our subdivision. It had a smoky stain running along the edge, just under the vinyl siding. I didn't think much about it, just figured it was dust from the cars, and moisture/dew in the air just drips it there. For the last 6 years, it didn't really change much.
30 days ago we put the house on the market to sell and of course thats when the problems start.

We were cleaning up the house, borrowed a neighbors pressure washer, and those stains won't come up. We cleaned the driveway, the back patio, etc, but they won't budge. IN FACT- they are now WORSE. They are no longer dusty grey like they have been for the past five years, but now they are looking more black.

I have one idea, and I don't know how much this plays into it. We had a black rubber welcome mat with a filigree design, that is at least 6 years old (it belonged to the previous owner) and it could be deteriorating and the black running into this stain. When I pulled the mat away, the filagree design was there.

We were thinking of using the new paint at Lowe's for concrete, but I don't know if the stains will show thru. If there is a cause that needs addressed? Any ideas what it is? On the right side of the porch, it starts about a foot in towards the door and run the length of the front of the house, getting lighter as it nears the left side of the house, but is under both windows. The porch wraps about 2-3 feet around the corner of the house on the left side, the stain doesn't go around the corner.





Any ideas, suggestions are greatly appreciated. Please keep in mind we are trying to sell it, not planning on being here any longer, trying to keep expenses to a minimum.

Thanks in advance

ETA: I live in the Carolina's. The house is built on a slab foundation.



__________________
CarolinaMom is offline  
 
Reply With Quote Quick reply to this message
Old 07-01-2014, 12:18 PM  
carnuck
Member
 
Join Date: Oct 2010
Location: Seattle/Lynnwood, Washington
Posts: 91
Liked 15 Times on 12 Posts
Likes Given: 3

Default

It looks like they used a chemical to wash the outside and didn't rinse it off good enough afterwards.



__________________
carnuck is offline  
 
Reply With Quote Quick reply to this message
Old 07-02-2014, 09:15 AM  
Chris
Guru of nothing
HRT_MODERATOR.png
 
Chris's Avatar
 
Join Date: Jul 2013
Posts: 1,311
Liked 114 Times on 97 Posts
Likes Given: 30

Default

You can try a mixture of muriatic acid and water with a scrub brush. The acid eats away at the concrete just a tad so if it is a surface stain that should work. If you do that you will want to wear safety glasses and gloves and cover your skin.

__________________
Chris is offline  
 
Reply With Quote Quick reply to this message
Old 07-02-2014, 05:12 PM  
nealtw
Contractor
 
Join Date: Nov 2010
Location: vancouver, b.c.
Posts: 9,904
Liked 814 Times on 727 Posts
Likes Given: 1405

Default

Do you have a slab floor in the house or is it structured with wood.

__________________
nealtw is offline  
 
Reply With Quote Quick reply to this message
Old 07-02-2014, 05:26 PM  
CarolinaMom
Junior Member
 
Join Date: Jun 2014
Location: Charlotte, NC
Posts: 5
Default

Quote:
Originally Posted by nealtw View Post
Do you have a slab floor in the house or is it structured with wood.
It's a slab foundation, about 10 years old.
__________________
CarolinaMom is offline  
 
Reply With Quote Quick reply to this message
Old 07-02-2014, 05:36 PM  
nealtw
Contractor
 
Join Date: Nov 2010
Location: vancouver, b.c.
Posts: 9,904
Liked 814 Times on 727 Posts
Likes Given: 1405

Default

Where we are the concrete slab out side would be a few inches below the slab inside. They may have waterproofed the foundation to high and that might bleed.
Or you have a roof leak and water is washing something down behind the siding
You may want to get a siding zipper tool and remove some siding at the bottom and make sure there is nothing going on. If you find nothing there take dated photos so you can show buyers , there is now big problem.

__________________
nealtw is offline  
 
Reply With Quote Quick reply to this message
Old 07-03-2014, 05:16 AM  
CarolinaMom
Junior Member
 
Join Date: Jun 2014
Location: Charlotte, NC
Posts: 5
Default

Quote:
Originally Posted by nealtw View Post
Where we are the concrete slab out side would be a few inches below the slab inside.
It is here too.


Quote:
Originally Posted by nealtw

Or you have a roof leak and water is washing something down behind the siding
You may want to get a siding zipper tool and remove some siding at the bottom and make sure there is nothing going on. If you find nothing there take dated photos so you can show buyers , there is now big problem.
That thought had crossed my mind, I was kind of hoping someone would rule that out, could be like opening Pandora's box- nothing but trouble inside.



I tried some bleach yesterday, some of it seemed to come up, so my theory of the deteriorating doormat did play a part in it, but it's not the cause of the problem, it was just making it more prominent.

I bought muriactic acid and supplies and will try that next. I know it's dangerous stuff. I've been watching some youtube videos and reading articles on it, but if you have some pointers, feel free to post them.

I had read that the acid can damage the vinyl siding, and many suggest using a garden sprayer but that just seems like it wouldn't give me the control I need right up against the house. I was thinking of just gently pouring it, and then, spreading with a plastic broom.

How long should I leave it there? It will foam up right? Do I need to neutralize it with baking soda before rinsing? I am afraid of killing the landscaping right by the porch, or is the extra water in the rinsing enough to dilute it?


The plan is to do the entire porch, not just the affected area, because if it's still there after the acid treatment, then I will paint the porch and cover it.

I never see moisture in those areas. It's dry even during bad storms. The porch is deep enough that the rain never makes it that far, and I never see it damp ( like I would expect if something is running behind the siding). The spot that doesn't have any stain, is at the end, next to the driveway, and the end 2 ft get sun, rain, traffic, no stain there.

Thanks for the replies.
__________________
CarolinaMom is offline  
 
Reply With Quote Quick reply to this message
Old 07-03-2014, 07:19 AM  
nealtw
Contractor
 
Join Date: Nov 2010
Location: vancouver, b.c.
Posts: 9,904
Liked 814 Times on 727 Posts
Likes Given: 1405

Default

I haven't used the acid so no help there.

Water does wick up the foundation and that is why there should be some exposed below the siding, you said the area exposed to sun does not have a stain. Perhaps a moisture test.

Lay a peice of clear poly on the concrete for 24 hours and see if water collects under it.

__________________
nealtw is offline  
 
Reply With Quote Quick reply to this message
Old 07-03-2014, 07:30 AM  
Chris
Guru of nothing
HRT_MODERATOR.png
 
Chris's Avatar
 
Join Date: Jul 2013
Posts: 1,311
Liked 114 Times on 97 Posts
Likes Given: 30

Default

I mix my acid 50/50 with water. I keep it in a bucket and use a brush to dip in then scrub or pour some out and scrub. I don't spray because it is dangerous enough in a bucket let alone airborne. Don't let it sit to long, you should be able to see it work immediately if nothing after a couple minutes than it is likely not going to work. You shouldn't have to neutralize it but I would rinse the area very very well afterwards. It is the same chemical you would use in your pool just in a stronger concentration. I have not had any ill effects on plant life from the rinse down but I wouldn't go pouring the stuff on plants. You can always mix up only a cup or so and do a test section to see if it works first.

__________________
Chris is offline  
 
Reply With Quote Quick reply to this message
Old 07-03-2014, 07:33 AM  
Chris
Guru of nothing
HRT_MODERATOR.png
 
Chris's Avatar
 
Join Date: Jul 2013
Posts: 1,311
Liked 114 Times on 97 Posts
Likes Given: 30

Default

Remember it is eating away at the concrete slightly so don't let it sit on too long. I had a leaky bottle and now have a permanent ring on my driveway but it sat there a couple hours.



__________________
Chris is offline  
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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 On
Refbacks are On


Similar Threads
Thread Thread Starter DIY Home Repair Forum Replies Last Post
Stain on Wall of home concrete RedBaron Bricks, Masonry and Concrete 6 03-19-2013 06:30 PM
concrete stain between slab sandstones betterluckythansmart Bricks, Masonry and Concrete 2 01-21-2010 04:06 PM
Concrete porch stain? house92 Bricks, Masonry and Concrete 3 01-16-2010 04:28 AM
Concrete stain/sealer removal??? kferar Bricks, Masonry and Concrete 2 09-09-2009 02:36 PM
making a simple outdoor kitchen semidevil General Home Improvement Discussion 4 04-29-2008 07:07 AM