Concrete Cleaning

[mrbojangles]

After some tips please gents.

 

The concrete round our house up in Chaiyaphum is probably about 5 years old now.

 

It's now getting quite black and big patches, I'm presuming some sort of moss or fungus and is starting to look quite shabby. I'm off up to the village next month and want to clean it and then hopefully seal it so the black patches don't return. 

 

Any of you guys have a recommendation for any type of cleaner and sealer? Probably going to buy a power washer to do it as well. 

 

[4MyEgo]

8 minutes ago, mrbojangles said:

Any of you guys have a recommendation for any type of cleaner and sealer? Probably going to buy a power washer to do it as well. 

 

You should buy one of those water pressure cleaners, we do ours every year. Not that expensive, although time consuming.

 

Shop around you can find them cheaper everywhere, here is a link with a picture in it.

 

https://www.officemate.co.th/th/สตาร์คเกอร์-เครื่องฉีดน้ำแรงดันสูง-100-บาร์-รุ่น-olympus-ofmy010229?gclid=CjwKCAjwzruGBhBAEiwAUqMR8E2AZov4p9xlA3a5soLgf2ohzVH4u5swjmq_hmqa56ltufFvT9Tv2BoCwEgQAvD_BwE&gclsrc=aw.ds

Edited June 21, 2021 by 4MyEgo

[Kwasaki]

We use bleach & water and brush.

[mrbojangles]

2 minutes ago, 4MyEgo said:

 

You should buy one of those water pressure cleaners, we do ours every year. Not that expensive, although time consuming.

 

Definitely buying a power washer but was wondering if there is a chemical that will stop the fungus or whatever it is returning and then a seal on top

[mrbojangles]

6 minutes ago, Kwasaki said:

We use bleach & water and brush.

 

The wife is up there at the moment. I'll tell her to try a patch with just bleach

[bankruatsteve]

Just now, mrbojangles said:

stop the fungus or whatever it is returning and then a seal on top

Good luck with that.  Please report back in if you find.

[4MyEgo]

2 minutes ago, mrbojangles said:

 

Definitely buying a power washer but was wondering if there is a chemical that will stop the fungus or whatever it is returning and then a seal on top

 

We did the inside of our house, e.g. polished concrete style with the semi-gloss look y mixing the part A & B products for it and then rolling it on, however never heard of it for outside as it could get slippery if wet and I don't think the sun/weather would do it good.

 

The once a year rain season event to use the water pressure machine can be relaxing as well, providing you have some shade, or a fixed brolly, no other alternative that I know of, and if you do buy and use the machine, best to do it when the rain season is over in my opinion, unless it's slippery now and after 5 years I would imagine it would be.

[mrbojangles]

1 minute ago, 4MyEgo said:

unless it's slippery now and after 5 years I would imagine it would be.

 

Yeah. In addition to it looking shabby, it is slippery when wet.

 

Might buy a power washer off lazada now and send it to the mrs. Job could be finished by the time I get there ????

[4MyEgo]

9 minutes ago, mrbojangles said:

 

Yeah. In addition to it looking shabby, it is slippery when wet.

 

Might buy a power washer off lazada now and send it to the mrs. Job could be finished by the time I get there ????

 

Just make sure it has a long handle so she doesn't, or you in the future have to bend over as it will take it's toll on your back as we are talking a half days job if its a big area.

Edited June 21, 2021 by 4MyEgo

[phetphet]

My neighbour has a Karcher pressure washer. Seems to have some sort of round shroud he puts on the nozzle when cleaning his terrace. Stops a lot of the mist and spray blowing everywhere. He did his a couple of  weeks ago and the difference after cleaning was  amazing.

There are some epoxy paints for exterior concrete, where you mix the paint and a plasticizer and paint on. But I think you have to treat the concrete with some sort of chemical prior to painting. Does give good  results, but you still might end up having to repaint every few years, so maybe better to leave bare and pressure wash every so often.

Another alternative if the arera is not too big might be to tile it with non slip tiles.

 

HTH

[ChipButty]

I've tried loads of things over the years on different properties I've owned Hydrochloric acid a gallon is cheap enough put water in the bucket first then pour the acid in make a strong mix then brush it into the concrete leave for 10 to 15 minutes then jet wash it, 

You will always get the same problem if its black algae it will come back,

I recommend you paint it I have done this even on sandwash, buy a good primer maybe give it a couple of coats as it soaks in good quality exterior paint like Dulux Weather shield it has a fungicide added to it and will stop anything growing on it like black algae

[jvs]

46 minutes ago, mrbojangles said:

 

The wife is up there at the moment. I'll tell her to try a patch with just bleach

We use bleach as well,no need to really work hard.Use a paintbrush to put the bleach

on,use a lot no problem.Let it soak for 15 minutes,rinse!

Done!

We used to do it with soap and a steel wire brush,hard work!Bleach does the work for you.

[Outbackoz]

In Australia  used to hav a similar problem in the rainy season, Used to make up a mix of sodium Hyperchlorite (Pool chlorine  12-15%)  3L,   200ml car wash,  150ml sodium triphosphate.  If it is a warm day 1 litre of water.  ( Caution This mix is extremely alkaline)  Wet down area to be cleaned, Spray over surface and brush. Leave for 15 mins and gurney off with a pressure washer  I always use gloves and eye protection when doing this. Biggest problem here is getting liquid pool chlorine.   

[mrbojangles]

2 minutes ago, Outbackoz said:

In Australia  used to hav a similar problem in the rainy season, Used to make up a mix of sodium Hyperchlorite (Pool chlorine  12-15%)  3L,   200ml car wash,  150ml sodium triphosphate.  If it is a warm day 1 litre of water.  ( Caution This mix is extremely alkaline)  Wet down area to be cleaned, Spray over surface and brush. Leave for 15 mins and gurney off with a pressure washer  I always use gloves and eye protection when doing this. Biggest problem here is getting liquid pool chlorine.   

 

Blimey. You're not called Walter White are you ????

[mrbojangles]

9 minutes ago, ChipButty said:

I've tried loads of things over the years on different properties I've owned Hydrochloric acid a gallon is cheap enough put water in the bucket first then pour the acid in make a strong mix then brush it into the concrete leave for 10 to 15 minutes then jet wash it, 

You will always get the same problem if its black algae it will come back,

I recommend you paint it I have done this even on sandwash, buy a good primer maybe give it a couple of coats as it soaks in good quality exterior paint like Dulux Weather shield it has a fungicide added to it and will stop anything growing on it like black algae

 

That's what I was thinking, something with fungicide in but never thought of weather shield. Isn't that for walls?

[ChipButty]

13 minutes ago, mrbojangles said:

 

That's what I was thinking, something with fungicide in but never thought of weather shield. Isn't that for walls?

Walls Floors all the same, cement

[Surelynot]

The main problem with power washers?...........  they are more addictive than crack cocaine........once you start you can't stop cleaning stuff.

Edited June 21, 2021 by Surelynot

[mrbojangles]

5 minutes ago, ChipButty said:

Walls Floors all the same, cement

 

I haven't walked on walls lately though ????

[Surelynot]

1 minute ago, mrbojangles said:

 

I haven't walked on walls lately though ????

Water?

[ChipButty]

Just now, mrbojangles said:

 

I haven't walked on walls lately though ????

Dont worry about it I have done loads using that method with great results, 

[mrbojangles]

1 minute ago, ChipButty said:

Dont worry about it I have done loads using that method with great results, 

 

Are you just talking about everyday exterior paint, not a flooring specific paint? I would have thought foot traffic would wear it down quickly,

[mrbojangles]

3 minutes ago, Surelynot said:

Water?

 

I tried that .............. once

[ChipButty]

27 minutes ago, mrbojangles said:

 

Are you just talking about everyday exterior paint, not a flooring specific paint? I would have thought foot traffic would wear it down quickly,

Same stuff I put on the walls thats why the primer is important 

[ourdon]

Bleach, warm water and a stiff brush will work well.  Paint afterward if you so desire (anti fungal paint suggested)  I find that wetting rags with the bleach mixture and laying them on the area of concern for 15 minutes helps.  It seems to kill the fungus and everything brushes off easily.

 

Pressure washers work well but be careful.  Many of the current ones are powerful enough to strip the seal and the top layer off of the concrete.  You can easily do quite a bit of damage and concrete work is expensive to refinish.

Edited June 21, 2021 by ourdon

[VocalNeal]

2 hours ago, phetphet said:

But I think you have to treat the concrete with some sort of chemical prior to painting.

 

First coat should be 80% thinners, 20% pigment. Top coat 100%

[Outbackoz]

4 hours ago, ChipButty said:

I've tried loads of things over the years on different properties I've owned Hydrochloric acid a gallon is cheap enough put water in the bucket first then pour the acid in make a strong mix then brush it into the concrete leave for 10 to 15 minutes then jet wash it, 

You will always get the same problem if its black algae it will come back,

I recommend you paint it I have done this even on sandwash, buy a good primer maybe give it a couple of coats as it soaks in good quality exterior paint like Dulux Weather shield it has a fungicide added to it and will stop anything growing on it like black algae

Yes acid does the job but it does leech out the bonding material over time. With sandwash/exposed aggregate that will cause degradation of the surface finish. 

PH value for concrete can be around 10-14 whilst hydrochloric acid around 3 depending on concentration. 

Sodium Hyperchlorite and bleach on the other hand generally around the 13 mark so no issues with surface breakdown.

If you are using a sealer, some products require a PH value of the concert finish to be below 10 which may require a diluted acid application.

  

[ChipButty]

2 hours ago, Outbackoz said:

Yes acid does the job but it does leech out the bonding material over time. With sandwash/exposed aggregate that will cause degradation of the surface finish. 

PH value for concrete can be around 10-14 whilst hydrochloric acid around 3 depending on concentration. 

Sodium Hyperchlorite and bleach on the other hand generally around the 13 mark so no issues with surface breakdown.

If you are using a sealer, some products require a PH value of the concert finish to be below 10 which may require a diluted acid application.

  

Im out of here you are too serious, get a life will ya

[Yellowtail]

Once you get it clean you can squeegee it over with a thin coat of portland cement  to freshen it up and seal it. Plastic cement is better if you can find it here. Cheap, easy & forgiving.

 

I would not epoxy over or otherwise paint/coat outdoor walkways as they get slick and water seems to pool on epoxy forever.

[northsouthdevide]

Every local farm supply shop sells what the locals call

"soda Fai",which is caustic soda.

If you want to be more eco friendly, you could try scrubbing in a mixture of white vinigar and baking soda.

The jet washer is a good idea as long as you don't point it too close to the affected area, and create lines.

 

[Yellowtail]

9 hours ago, northsouthdevide said:

Every local farm supply shop sells what the locals call

"soda Fai",which is caustic soda.

If you want to be more eco friendly, you could try scrubbing in a mixture of white vinigar and baking soda.

The jet washer is a good idea as long as you don't point it too close to the affected area, and create lines.

 

 

Is that not mixing an acid and a base together?