Anyone know about cleaning concrete?

[fluxlizard]

Hi guys,

Does anyone know about concrete and how to clean it?

This is one of the last big things in my lizard building refurb job after the fire this spring. My concrete floor is dirty. Black parts from the fire, and although I cleaned it a couple of times scrubbing with an old broom and purple power 2 x and then spent all night one night scrubbing it from 6pm to 6am with a machine that uses a circular 17 inch (? I think) pad I was unsuccessful after a couple of heavy scrubs and rinses with purple power or some such heavy duty biodegradible degreaser. It's improved but still dirty. It's a pretty large floor 30x42' so it took a while but I managed to get 2 good scrubbings and rinsings 2x (so really 4x I guess) and I still had a grey slurry type thing on the floor which dried into grey powder-flim.

I was told by lowes to use muratic acid diluted on the concrete to clean it up and then seal it.

I was told by the concrete company who poured my pad originally 12 years ago after talking with lowes not to do that and just to use a degreaser. I think it might have been because it would rough up the surface.

But I think the fire maybe already did that. There are rough spots and spots I'm pretty sure may have flaked off after the scrubber pad went over it.

So, I'm posting here to see if anyone has any recommendations I might consider- I'm not sure whether to trust lowes or the concrete company of if there is a better way (pressure washer?). I don't think the pad was sealed to begin with (doh! I didn't know anything about concrete being so pourous before the fire) and so I'm sure there are years of abuse prior to the fire ground into the pad as well- hay and clay dirt mud from outside, etc.

I purchased this product before I realised that cleanup was going to be the problem it is:

http://www.foundationarmor.com/armor-s1000-concrete-sealer/

And would still like to use it, maybe with a epoxy surface coating. My primary purpose is to prevent odor, but the discoloration and roughness of the surface of the pad now makes me want to put a surface coat of something solid colored on top maybe.

Anybody do fire cleanup or know anything that would help me?

I've had to cover costs out of pocket and do things myself- it's been a long hard job. 3 24' dumpsters of fire damaged equipment tossed out- some of it 15+ years old, and lost at least 10 years careful breeding work on a few species. I stripped things down to the studs, sanded and dry chemical sponged every last inch of the wood, replaced wiring, insulation and drywall, and now the concrete pad is the last big thing to overcome and I'm kind of lost on how to proceed or even how to located someone who could give me good advice about how to proceed.

So anything I could do for the concrete myself would be a great help. But if someone who knows what they are talking about suggests professional help for cleaning the concrete at this point, knowing what sort of help to get and why would also be very helpful.

Thank you much!

 

[MelissaB]

Do you have or know someone with a power washer you can borrow? That's what I would start with. It might flake off some of the chipping concrete, but if it's already flaking off from the fire, I don't think it would hurt anything. I think the acid might etch the concrete. Isn't that what you use if you're going to stain the concrete, to open it up to accept the stain? Sorry I'm not much help.

 

[Lathis]

I do building restoration for a living, so I know all about cleaning masonry

Fire damage does indeed increase the porosity and surface profile of the concrete. Degreaser is your best bet for cleaning staining from fire char, but you likely will not be able to clean the discoloration from the concrete entirely. Only reduce it a bit.

Muriatic/Hydrochloric acid might remove the char but only by melting the top surface of the concrete away. Since fire char has some penetration into the concrete material, you would probably have to remove quite a bit of material and use a very aggressive solution.

Also: Muriatic fumes are absolutely lethal, so I would recommend using it even in dilution with extreme care. (I have experienced laborers on my projects every year that end up in the hospital because of chemical burns or respiratory issues. It's a hazard of the trade when people get too relaxed working with industrial cleaners.) Plus, muriatic acid creates calcium chloride salts inside the concrete that are almost impossible to completely rinse away - this will negatively affect any sealer or coating you want to put on the floor later.

If you have scaling/flaking surfaces, I would recommend tooling off the damaged areas. You can seal over the imperfect floor or use a polymer leveling product that can be "feather edged" to fill in the damaged areas (make sure it's stainable or compatible with whatever sealer you are using). Don't use a skim-coat of concrete or quickcrete; it will just flake off.

If you are etching the floor to receive a stain, the specific stain manufacturer will have surface prep recommendations - I would recommend using a manufactured surface etcher since they are likely to have pH buffers, surfactants, and other modifiers to control and improve performance that dilute pure acid doesn't have.

I would recommend against an epoxy floor coating unless you are sure the slab has a vapor barrier under it. If it is a slab directly over gravel or dirt (no plastic sheet), the epoxy coating will start to fail immediately because of trapped moisture. A stain would be a better option because it will let the concrete breathe and still be a very resistant floor treatment. I'm not sure what is available in your area or at regular hardware stores. You could always check the local construction material supplier or reach out to some flooring contractors for excess material they might have. You sound pretty handy, so that's something you could do yourself.

I really nerd out on this stuff

 

[fluxlizard]

Thank you for your response.

Things I don't understand cause I'm a noob in over his head-

"tooling" off the damaged areas-

What tool would I use to do the tooling? I think you are talking about grinding the damaged areas with something is that right?

Is there a polymer leveling product I can get locally from lowes or home depot that will do the trick (I doubt it) or where might I go to locate such a product- I have no idea even the sort of local supply place to get decent stuff and have read that sealers etc from lowes and home depot are not very good.

I'm sure I just have gravel without a vapor barrier beneath the slab. The slab is the one bit I had professionally done when I built the lizard house but I don't remember them lining with any sort of barrier- just gravel and metal grid of course.

One problem I'm worried about is odor from the fire having been absorbed into the concrete and then slowly being released forever after and having a strong smell in the building. I'm not sure yet about this as I've got the windows and doors removed and lots of air has been moving for a few months so I can't evaluate how bad the odor will be. I'm afraid it will be pretty bad- but that could just be my fears. Will I not need to seal the floor to prevent odor? Or do you feel the odor will not be too bad? Will stain do anything for the odor?

What do you think about the product I linked to? It is a deep penetrating sealer with a lifetime guarantee and is supposed to strengthen the concrete as well. Seems like better than surface sealer and maybe would work without the vapor barrier or do you think not? And will my 12 year old floor plus fire damage have "clogged pores" and not be able to absorb a penetrating sealer anyway?

I really appreciate your advice. Thank you so much.

 

[Mike Fisher]

I would chip off, debrade the bad spots then skim coat over them. Be sure to brush on a bonding agent to the old before applying the new, and make sure the patching compound you are using is made for the right thickness you are patching. The patching stuff is just a special mix of cement, you'll find it at Lowes. I believe it is called "patcher". It think it comes in a tub with green lettering. Be sure to get the bonding agent there too.

Then a diluted acid wash then dye, then sealer. Just what I would do.

 

[Lathis]

Mike got it in about 1/3 of the words I used

The S1000 is a penetrating silicate, so I think this would be a good use, provided your slab is very dry during application of the sealer - damp concrete will accelerate the cure on these products and you won't get it to penetrate properly. Don't over apply or you will get shiny puddles.

As for the odor, I am guessing if the smell is coming from the concrete, a sealer might reduce the odor bit may not block it. Lots of ventilation and time is probably your best option. Let me think about that and see if I come up with any ideas...

 

[fluxlizard]

OK, thank you very much guys.

Just to make sure I understand- if I use a stain, then I can still use the penetrating sealer afterwards you think?

How long between steps would you guess? I know you can't be specific, but is 3 days usually enough to dry out between steps? 5? Do you know if the "plastic sheet" test is worth anything (lay a sheet of plastic out on the concrete if there is condensation the next day the concrete still isn't dry, if no condensation concrete is dry?)

Oh- one big question- what tool would I use to debrade the concrete?

Thanks!

 

[Lathis]

The tool is called a scabbler. Essentially it is a pneumatic hammer with a dozen tiny heads. You might ask at one of the bigger hardware stores what they have for rent to do that. It will be dusty - wear a mask and be safe.



You should be able to stain then seal if the products work with each other. Does the manufacturer of the S1000 have a stain, too? Off the top of my head, a few days between products sounds right. Always check the application instructions, though.



I would definitely perform the plastic sheet test. They have fancy vapor transmission test kits for slabs that include a dessicant, but if you put down a heavy mil plastic, seal the edges with tape really well and check it over 48 hours for condensation, you should get a rough idea if you are having vapor drive through the slab. You could put a digital hygrometer under the plastic to measure RH. You probably have one already being a cham person

 

[fluxlizard]

Cool- thanks so much. I am feeling much more confident after your advice.

That has been half the battle for me with this cleanup and rebuild- fear of doing something wrong and creating a permanant problem. I probably have the cleanest studs and inside roof in the attic after a fire ever. LOL

 

[Lathis]

Yeah, it sounds like it was pretty catastrophic. I can't imagine having to clean up after something as destructive as a fire. I'm afraid to ask if you lost any animals.

I did some digging on removing smoke smell/char staining from concrete. There are some proprietary cleaners out there... but they all seems to be degreaser/solvent based. You might be at a point where an air purifier or activated carbon might be the best way to address lingering smoke smells.

I stopped by Lowes and the HD to look at concrete stains. They had maybe a half-dozen earth-toned stains and both matte and gloss tintable sealers. You may not need to do both if you can get a sealer tinted. Brands were Valspar at Lowes and Behr at the HD. Unless the surface of the concrete is very friable (sugary, powdery, soft), you probably don't have to use a densifier like the S1000 - that's where the $110/gallon goes. Just a thought.

 

[fluxlizard]

I lost more than few. like 95% Lost to me. Somehow 2 of my tortoises made it and some bearded dragons that managed to jump out of burning reptariums down to the floor made it as well. A few lizards were already outside or are house-pets and they made it as well- tegu, australian water dragons, the 2 house iguanas and bearded dragons.

As if the horrible loss of life was not enough, it was terrible timing too- after many years of struggling financially just to keep things going around here this was looking like a really really excellent year for the lizards. And I do mean excellent, and it was off to a great start- I was about a month into hatching. I had done a lot of holding back and building large groups as my goal the past several years has been self sustaining populations. And I had done some selective breeding with the bearded dragons and had a couple of things that were unique but probably a generation or two off from introducing. I'd been selecting for one of those things for over 10 years.

It was a huge blow and took a lot of getting used to for a few months just to believe what happened- lotta shock. Now it seems like before was a dream and this is reality, which I suppose is a better state of mind.

I've had to do cleanup myself as I didn't have insurance to cover things and no way in the world I could have afforded to pay someone to do it. (I know because I did get some estimates and some of the contractors were kind enough to offer some free advice when they saw I couldn't afford to hire them- I didn't think far enough ahead to get advice on the pad though- I thought it would be a simple cleanup and surface seal).

It's been a long haul and now I'm trying to put together some breeding groups so I've got a few things to start out in the building when it is done. I did luck out a little bit in that not all my bearded dragons had hatched for the season and I had my incubators in my house, not the lizard building. But moving forward on bearded dragons alone isn't going to work and I may have lost anything that was unique in the genetics. But at least the colony I've had since 1994 can keep on and maybe with a little luck I can bring something out in the genes.

So, it's sucked pretty bad. Electrical fire- went to bed on top of the world, woke up, noticed soot marks on the doors to the building, went out fearing the worst, opened the door- black as night smoke- couldn't see 5 feet in the building. But fire already snuffed out- probably lack of oxygen- building well insulated and never dropped below 50 even without heat and 17 degrees outside- probably the 1200 sqft concrete floor. Banks of reptariums had burned and across the room from the fire, melted. Frames even burned- even the 1" home-made pvc frames. It was really quiet inside there. Everything was covered in black soot from the plastic/pvc/and whatever fabric reptariums are made out of. I had over 100 enclosures in there, counting the ones used for the newly hatched babies.

Thankfully, no damage to the studs so the structure was OK, but had to replace insulation, sand and wipe down with dry chemical sponges the studs and walls and attic, replace the drywall and electrical, windows cracked from heat had to be replaced- am at that stage now- painting, replacing windows and doors and then I'll take care of floor in a few days- hopefully at least starting on final cleanup of floor in a couple more days. Already described cleanup 2x without the floor machine 4x with.

Can't describe feelings of clean drywall up, wiring in place and insulation in place after having to rip everything out. This past week has been a big lift- took several weeks (longer than that really) of cleaning and sanding and wiping after the initial cleanup (3x 24' dumpsters full of enclosures and equipment and tools aquired over the years plus drywall and insulation) before I could start to put back together again.

So right now- with your advice on the floors and going to check out the stains I could possibly use and such- I can't thank you enough for your kindness. Thanks so much for your advice and giving my problem some thought and dropping by the store to check the products.

 

[Lathis]

Oh, man, I can't even imagine. Your fam and your animals have my deepest sympathies. That is so rough.



If you're anywhere near KC, I'll drag the hubby over for a weekend, and we'll help out with something. Just shoot me PM.

 

[fluxlizard]

Thanks much for the kindness, but I'm nowhere near you- I'm in VA.

 

[Mike Fisher]

Oh- one big question- what tool would I use to debrade the concrete?

Thanks!

I'd go old school on the loose stuff, pry bar, chisel, hammer, whatever you got. If you tap on it, you'll know if it is loose and needs to come off just by the sound it makes. Sorry to hear the sordid details, hang in there, in a few years it will all seem like a bad dream.

My basement and foundation were destroyed in a flood in 1996, then I lost over 3000 chameleon eggs when the subcontractor doing the repairs killed power to my incubators. So yeah, I've been there too. Good luck.

 

[Lathis]

That's true, if it's bad concrete it will sound "flat" when you hit it with a metal hammer. Good concrete has a nice, clear "ring". It's hard to imagine from someone describing it, but when you hit a bad spot, you will know. hammer and chisel or the sharp end of a masonry hammer will probably work fine for the surface area you are dealing with.



Do they have good beer in Virginia? I've been known to travel for a good microbrew...

 

[fluxlizard]

Ok- I don't think it's that damaged maybe compared to what you may be thinking- just a thin layer at the surface in a few spots- overall still pretty good. One spot near the fire about 2'x2' looks exposed for lack of a better word- I'll need to take a closer look tomorrow but glancing at it a few days ago when doing drywall looks like maybe the gravel embedded in the cement may be visible or something (maybe?). And that may be 1/8" maybeee lost from the top. Other areas probably less than that- just very top flaking off maybe- not much super serious really deep (I don't think- like I said- floor is next. When I finished scrubbing I had been up all night and when I saw that the floor would take longer I decided to go straight into sealing the attic with killz and wiring and drywall and stuff and come back to the floor again last at the end- which may have been a mistake but I figured once I had drywall painted I could cover with plastic - I didn't want to delay everything to figure out the floor adn thought I could work out what to do while working on the rest.

The tapping is a great suggestion maybe to help double check- I'll give it a go.

Beer- I don't know- could probably locate someone who does But I hope it isn't so serious and that I'll be halfway through before you could get here anyway. I already owe you guys a beer just for the consulation!

I've done the incubator thing too several years back- big incubator and bad 15 year old analogue controller- expensive for it's time but failed. Nearly 1000 eggs. That used to be the worst day of my life before this one. Hope this event is the last worst day of my life for many many years.

 

[Mike Fisher]

Ok- I don't think it's that damaged maybe compared to what you may be thinking- just a thin layer at the surface in a few spots- overall still pretty good. One spot near the fire about 2'x2' looks exposed for lack of a better word- I'll need to take a closer look tomorrow but glancing at it a few days ago when doing drywall looks like maybe the gravel embedded in the cement may be visible or something (maybe?). And that may be 1/8" maybeee lost from the top. Other areas probably less than that- just very top flaking off maybe- not much super serious really deep (

Then you don't need patcher, you need topper. The trick to that is to make it fairly thin so that is self levels a bit after you spread it out. Make sure to use a nice wide trowel and float. Then after it starts setting up a bit, I use a brush wetted in bonding agent and feather in the edges so that the repair blends smoothly with the old. I'll say it again, make sure to use a bonding agent on the old stuff before putting the new on, otherwise it will just flake off in a few years, leaving craters behind.