We have a concrete patio that has some minor damage (see pictures) caused by time and some overly energetic dogs.

In addition the patio has spots all over it that appear to be moss or mold (see pictures).

My wife would like to use some kind of decorative stain on our concrete to make it look nicer but i'm wanting to repair / clean it first, of which i've never done either.

First how can i repair the damage? Some kind of patching?

Second how can i clean it? Water / bleach mix? Or is a power
washer required? Don't want to further damage the concrete.

Third, some kind of guidance on an economical approach to making the concrete look better but not break the bank.

Thanks all!

 

Wow, now THAT'S disappointing. 33 views and not a single reply. Better luck tomorrow i hope

 

Bump.. still looking for help.

 

Okay, here's some advice. Powerwash it clean with a 3000 psi minimum pressure washer. Gas powered with a fan tip (green). An electric washer will not have nearly the power you need. This will take off any loose material as well as the moss/mildew.
Get some quikrete concrete resurfacer from Lowes and closely follow the diections on the bag. You can either do a complete overlay with it or use it to spot-fill the divots. Let it cure as per the directions on the bag.
While at Lowes buying the resurfacer, check to see if they sell concrete stain. Last I saw, they had both pigmented acrylic stain and acid stain. Pick whichever one your wife likes best.
Apply the stain exactly as stated on the can's/jug's label. Seal with whatever product the stain manufacturer recommends. Results will be directly proportional to your ability level and how closely you follow directions, especially those regarding surface prep and timing (drying and curing times before applying stain or sealer). Good luck.

 

As I look at this I think lunar landing. Been pouring concrete for over 30 years and never seen anything like this. The Crete there was poured and sprayed down with a hose to take the top off and expose the stones. I never agreed with it because it causes a weak top. It was mainly developed because the art of finishing Crete is getting lost and this is easier. Explains it on the Hotels and strip malls.

What exactly did the dog do? Never saw a dog be able to chip/harm/dig concrete in my life either. Saw pop stains and thats it.

Power washer is the best way to clean any concrete. Its a good test to see if its sound. If the Crete there starts to flake up and dig a whole with the pressure washer, keep pressure washer and throw out the concrete. These no topping material that will stick to soft flaky concrete. I like the old screw driver test. See how easy it is to scrape a gouge in the Crete.

The other thing is I'm concerned on the "topping" of choice that may be used here.

To add to pecos good advice on staining/acid , the coloring will be determined more on how thick the topping goes on in differences places which effects the amount of stain it will absorb. Like staining wood and the grains of hardness takes less stain.

Well I got my 2c in and hope it works out but have my doubts here. I don't know how big this area is but

Good job Pecos on the pressure washer part Dead on...

 

21boat,
The concrete shown isn't exposed agg, it's just old and badly weathered. The aggregate you see in the top photos is sand, it's just that he took extreme close-up photos of the popouts so it looks larger like pea gravel. in the bottom two photos with the moss you can see the broom marks from the original finish.
I agree that the quikrete resurfacer is probably not the best product on the market, but it is probably the most readily available. I used it once and it did a pretty good job. My only problem with it is that it is much darker gray than concrete. In my opinion, a pigmented stain would be better on this job because it would hide the color of the overlay. Acid stain will be extremely dark over the quikrete resurfacer. The downside with pigmented stain is that it will need to be re-applied periodically.
I wondered about the dogs too! If they can damage concrete, I'd certainly never let them into the house!
2 questions...How old exactly is this concrete? and "do you apply de-icing chemicals to it in the winter?" They can cause damage as shown in the pix, but usually on a larger scale.

 

Hi pecos. Your eyes are seeing different then mine.

I'm looking at the blade of grass for a scale in stone. Its pea aggerate.. The reason I assumed it was a pour and rinse is because of the Baby stone/aggregate in the Crete which is not everyday Crete stone not to mention the colors in it.
Now the other thought here is a home owner bought the tiny stone and hand mixed it. This would explain the easy to mix Crete in stone and also the obvious weak mixed Crete.

Boy over 33 years of pushing the gray beast I never saw Crete out of a truck this worn and soft looking.

Puncture... Lets do the proven scientific cave man test here and maybe put this to bed. Take a hammer and give the top a good thump and listen to the sound. See if it sounds soft then it is soft.. Now go bang on an old good Crete walk somewhere else and here that sound.

Also do the scratch test. If you can take the claw on that hammer and get a scraped grove and turn it into a small gully then keep hammering it and remove all of the crete....

 

Boat,
there are five different photos top to bottom. The only one with grass is the second from the bottom one, which shows no aggregate. It only shows the round spots of moss/mildew on the broom finish. It threw me at first too because there is no border or seperation between the different photos.

 

Hey guys.. thanks so much for the replies.

I apologize for the confusion. I took 5 pictures hoping to be thourough and cropped the first 3.

The very first one, yes, is an extreme closeup and then i cropped it just to get the damage in so it's extreme. The pictures with the mold are just point and shoot no cropping. Will do the tests over lunch and let u know.

 

Ok so i know it's been a long while but i wanted to come back and answer some of your questions / tests posted.

The concrete patio was made in 2001 when the house was built.

I did the hammer and hammer/screw driver test.

Hammer made white scratch marks on the cement but no divits in the crete. Hammer / screw driver pounded into the cement gave off the same sound doing the patio as it did the side walk in front of our house, as well as the concrete landing in front of our house.

Hope that helps.

 

If the screwdriver didn't drag a gouge in it, the top is strong enough. One question you forgot to answer was the one about de-icing chemicals or salt. My advice from before about resurfacing still stands. It will fix the surface and is probably your most economical alternative. I would add that you should never apply de-icing chemicals after you fix it (or even if you don't) because it will continue to be damaged.

 

Not 100% sure on that question. We've owned the house for 6 years and i may have used salt to help remove ice once in the six years but not even certain about that. Usually I either shovel it or if it gets bad enough i'll bring the snow blower back and run over it. Have used the blower several times the past two years. Mebby that's the cause?

 

No, a blower wouldn't do it. Salt and other de-icing chemicals can eat away at the concrete, making the surface scale off and pit. If you don't use it, it must be some other reason.

 

Well we're not the first owners of the home. The first owners had the place for 2-3 years before we moved in, so they may have done something??

As far as staining the cement goes.. my wife has picked out a color from a brochure and on the brochure it states something about "scoring the cement" before applying the stain.

Any idea what that is and if it's pretty 'do it yourself' friendly?

Edit: Adding a second question. If i decided to put a fresh top on the entire thing is that a DIY project? I've used Quick Crete several times when installing 4x4 posts for a small decorative fence around our air unit, 4x4's for lattice support, and one for an extremly high bird house but never for patching or a full on project. What's it entail?

 

Forgetting about the weathered surface, the holes you are seeing are "pop-outs".

That happens to some kinds of aggregate that are subjected to cold and moisture. Salt and fertilizer will make it easier to happen and increase the amount of "pop-outs".

Dick

 

That's the Chicago area suburbs to a T

 

Scoring means cutting shallow grooves in the concrete, usually in a grid pattern. People sometimes score and then stain concrete to make it resemble seperate tiles. It is not something that has to be done unless you want the tile look.
What kind of stain did your wife pick?
The quikrete resurfacer is geared toward homeowner/diy use. That's why it is sold at Lowe's, etc.

 

Ok round 1 complete. . . rented a 2000 psi cleaner from homedepot and it worked likea charm. Hopefully next time I can locate a 3000 psi as it might make things a little easier for me. Next the quick crete patching..

Oh and the question about what kind of stain did my wife pick...

it's Behr semi-transparent color concrete stain (chicory lower stc-32)