How to bond new concrete to old concrete

I have a new KZbin channel entirely dedicated to concrete - Please subscribe to Creating Concrete (with Steve) / @creatingconcrete
From www.swimmingpo... - In this video Steve explains how to make a bonding slurry for bonding new concrete to older, existing concrete. For a follow up video of making a slurry watch this one:
How To Make A Concrete Bonding Slurry - • How To Make A Concrete...
_______________________________________
Introduction To Concrete Bonding - • Introduction To Concre...
Bonding New Concrete To Oily Concrete - • Bonding New Concrete T...
How To Prepare Old Concrete For Bonding - • How To Prepare Old Con...
How To Acid Wash Concrete - • How To Acid Wash Concrete
How To Bond New Concrete To Old Concrete With A Latex Slurry - • How To Bond New Concre...
Bonding New Concrete To Old Concrete With SBR Latex - • Bonding New Concrete T...
How To Bond New Concrete To Old Concrete With PVA Slurry - • Bond New Concrete To O...
4 Ways To Bond New Concrete To Old Concrete - • 4 Ways To Bond New Con...
_________________________________________
How To Make Red Concrete - • How To Make Concrete Red
How To Make Black Concrete - • How To Make Concrete B...
Colored Concrete Results - • Colored Concrete Results
#swimmingpoolsteve #concrete

[@pgk1940]

This is an excellent example of a proper "how to" presentation - very informative, easy to understand, no unnecessary chit chat or attempts at humour. Thanks ever so much!!

[@username8171]

And no dam blaring guitar at the beginning !

[@Naturalcorpse]

It absolutely is. I've got it bookmarked for use as an example to show students.

[@kennyp54]

I agree. To the point and informative. Thank you.

[@workonitm8]

Yes, very good. Clear instruction with no "filler" chit, chat.

[@Hey_Jamie]

Unnecessary attempts at humor? Wow you sound like you’re fun to be around 🙄

[@marvinpues]

Straight forward, quick, clear. Holy cow, a rarity on youtube. Thanks.

[@sweet1lew1968]

As a structural engineer who has worked in concrete industry I can verify the information as accurate and succinct!

[@arthurdavis3365]

***Thanks***

[@MitzvosGolem1]

Not in structural compression or shear only for cover applications. Still considered a "cold joint" as per ACI ASCE etc. No white glue or any organic based material is ever allowed in any certified job... There are products engineered for this .

[@alexanderellul2701]

Hello Steve thanks for sharing your knowledge, could anyone please advise on whether same technique could be used for spalled concrete ceilings ?

[@jameskarr5550]

@@arthurdavis3365 I have question if U don’t mind. There is a vault of a friend that the headstone was knocked over and cracked, the concrete top. I’m no concrete man by far but have used sealants that don’t hold up well. I was thinking fill crack which is pretty big it split the concrete top and fill with foam then come over with a mortar of some type. I realize it won’t look great but I’m trying to stop rain water from entering vault... it seems the immediate family isn’t going to do anything and I’m limited to what I can do. Thanks for any suggestions!!!

[@YAWN....]

My hero...

[@jonasnyberg7728]

Its a good way, not the best way. There is an old trick in the book that i will teach you MR steve.. you simply mix the cement with tiling adhesive. And if you think about it.. it makes sense ;)

[@joe-ge5fq]

I've done many patches in the last 45 years. You got it. Be sure your slurry is still tacky when you put your new concrete down. I patched a floor in 1977 it's still holding.

[@daleval2182]

Excellent you added the point he skipped. Awesome. In adding a glass stepping design in top , what could I pour over too to give a protective clear coat ? Would well bond on top work do you think, or do they make an acrylic clear over coat for concrete ??

[@Swimmingpoolsteve]

@Mike Palacios It means that slurry is still wet. You mix it and apply it to the old concrete and then apply your new concrete right away before the slurry becomes dry.

[@supjay3945]

@Mike Palacios my thoughts as well

[@PeopleHealthTru]

@@Swimmingpoolsteve How much glue?

[@glennmiller9768]

By far one of the best how-to videos I've seen on KZbin. Clear and concise. A big thumbs up.

[@totallycv2388]

Dude explained the instructions better than watching actual vid tutorials. Your thought process and info delivery is insanely clear

[@mikecerda7228]

I always suspected these bonding sealing liquids looked too much like cheap white glue

[@stlbusker3025]

No Music.... No Family Pets.... No Jokes That Have No Relevance.....Just Right To The Point Good Information.... I Tapped The Like & Subscribe For Those Simple Reasons.... Take Note KZbin Video Posters!

[@Swimmingpoolsteve]

Cheers, thank you

[@CameronCarter1]

Muriatic acid = Hydrochloric acid . Portland = cement. White glue = PVA = (polyvinylacetate).

[@Swimmingpoolsteve]

If you are interested in more technical breakdowns of bonding agents please read the full article: www.swimmingpoolsteve.com/bond-concrete.html

[@skinnygumbo2700]

Oh, come on people, I thought you only changed the name of football to soccer, now you are messing up with the hydrochloric acid name? 😁 Why?

[@MrHughk1]

@D Mills We are mighty pissed off, you cant even spell colour you call a podger an Irish spanner, you call a split pin a cotter pin, god only knows what you call an actual cotter pin. Chips become fries and what you call chips we call crisps, trunk for boot, you put light switches up, we put them down, you wear your pants on the outside, we wear them on the inside. And I have to add lol :/)

[@victoreous626]

@@MrHughk1 But you chaps (folks) drive on the wrong side of the road.

[@MrHughk1]

@D Mills Fuck you, I was just joining in the joke but you turned out to be a fuckwit.

[@L.Scott_Music]

Something to mention just because some people don't know this, apply your final patch cement immediately after apply applying the slurry. Don't let the slurry dry at all.

[@richardpalusaar3364]

You answered the very question that popped into my head when the video ended, thank you!

[@christophephilippe1481]

Thankyou I was looking for this exact question to be answered appreciated

[@MANNO_GG]

Yup.

[@bryancoombesart]

Thanks! last bit of info i needed

[@danielplainview3003]

That was my 1st question..thanks!

[@Swimmingpoolsteve]

IMPORTANT UPDATE - This video is a simplified explanation of how to bond concrete. In response to how popular this video is I created a much deeper article about concrete bonding, using many of the comments and products mentioned in the comments here. PLEASE READ the full article: www.swimmingpoolsteve.com/pages/bond-concrete.html This video is suddenly getting a lot of views. Here is a question that was asked by quite a few people so far - WHEN do you apply the new concrete? Do you let the slurry set up or slurry then concrete right away. Here is the answer I gave to someone else down further in the comments: Do NOT let the bonding slurry set. If it sets, you need to add more bonding slurry and wet it up again, so try not to let that happen. On a technical note, if I were to describe the PERFECT situation, it would not be putting concrete over wet slurry either. If you had to err on the side of caution, add the new cement over wet slurry, never dry, but the magic middle zone is to watch the slurry. When you apply it, it looks wet. Sheen even. The perfect time to apply the new layer of concrete is when the slurry begins to have a haze look, as opposed to wet sheen. This is the ideal point at which to add the patch. NEVER over dry slurry though so be careful.

[@kamleshverma9761]

When It is more effective in summer or rainy season?

[@Swimmingpoolsteve]

@@kamleshverma9761 I don't understand your question. Solid concrete working fundamentals apply regardless of the season or climate. If you are asking about optimal environment for doing this work, certainly cooler and damp is better than hot and dry.

[@OffGridInvestor]

I work for a place that hires modular formwork and we sell that bonding stuff. Customers get it on the plywood and it's almost impossible to get off without destroying the black film on the plywood.

[@Swimmingpoolsteve]

@@OffGridInvestor You bet - it is a universal bonding agent which basically allows you to glue anything to anything - within reason. Glue glass together even! The bond on wood, much like with wood glue, creates a joint between two planed surfaces that is essentially as strong as one piece of wood. For this concrete bonding slurry you actually don't use very much. However much water you would be using just use 10% less water and make up that difference with Weldbond. It really is not just gluing concrete, but it does make a difference with how sticky the mix is, and how well it bonds. Further to this, for any other people reading this in the comments here, this is not my special trick or anything - a bonding slurry with Weldbond is the industry accepted practice for bonding new concrete to old concrete...that is unless you are like me and own a shotcrete company because then you can bond with shotcrete and no intermediary layer required and there is ZERO cold joint even under labratory conditions. If you don't want to spend $30,000 on a gunite rig then your next best option is this slurry. Thanks for reading and be sure to subscribe!

[@ralpherizonie1785]

Swimming Pool Steve utter rubbish u forgot to cut and pva

[@goochma]

I've been building, repairing and servicing gunite swimming pools for 23 years yet I'm still learning so much watching your videos. These are great tips that will come in handy with my everyday job. Thanks a ton Steve.

[@magouliana32]

Since your an expert what type of in ground pool is best for northeast climates? Vinyl liner ? Thanks

[@MonzaTom]

Well done! I do some concrete work (General Contractor) and I will remember this. Also, good job not blowing your own horn at the beginning and end of your video! You got right to the point!

[@danacarney9951]

I was wondering if I can ask a question. I have a concrete patio that has 3 old peeling layers of peeling paint. I'm looking for an inexpensive way to beautify the concrete. Do u think I can apply a layer of epoxy or bondo on peeling paint, let harden, add 2 coats of primer and 2 coats of concrete paint I will have a lasting finish?

[@sislau]

This is literally the issue I'm facing, and you've answered the query beautifully. Thank you tons! I feel confident enough to tackle the problem. Well done. Great video :)

[@billsmith9711]

would you suggest this process for re-plastering swimming pool surfaces where maybe 1/8th - 1/4 inch has de-laminated and made smaller shallow spots? I am considering the process of repairing my plaster and I am familiar with an acide wash for the whole pool. Please advise.

[@Swimmingpoolsteve]

Specifically yes.

[@crisc9280]

So muriatic acid, damp and slurry with glue before concrete. Got it. And thank you for getting straight to the point.

[@psidvicious]

Why not just use a concrete bonding agent? There is a ton of different brands. Some better than others. Some are colored so you can see which areas already have it applied. And you don’t have to hurry up and apply your finish coat before it drys. A commercially available bonding agent would probably be a lot cheaper than white glue.

[@Swimmingpoolsteve]

This article explains in detail the product I am talking about in this video as well as a number of other popular bonding adhesive options: www.swimmingpoolsteve.com/pages/bond-concrete.html

[@chrisgraham2904]

If you have to skip the slurry, due to a lack of pure portland, the concrete adhesive or thinned PVA glue can be brushed directly onto the wet/damp surface that you intend to bond to. Apply your first skim coat before the PVA dries.

[@JonMcG]

one thing Einstein ....... Best way to teach ( Proven fact ) ........ Audio Visual . Perhaps next time show a working example . It would certainly help idiots like me to better understand before attempting their very first DIY Pool fix . 😏

[@ltodd79]

My old father used white glue in concrete he poured 60 years ago and it's still good!

[@MrJFoster1984]

Do not use white glue/pva because it can re-emulsify under wet conditions. It needs to be an SBR Latex additive mixed with the cement. Best way is to scabble/gouge the surface with a chisel point to give it a roughness, acid wash, high pressure clean, use some form of 316 SS anchor/pins fixed to the existing substrate with resin, dampen the surface, use the slurry mix brushed on thick immediately prior to laying the new concrete.For best results use a polymer modified concrete patching compound with the same brand of primer. After poured use a concrete curing compound sprayed over the repair following manufacturers directions, or cover with a plastic sheet 👍

[@zorroonmilkavitch1840]

If you ask me this is by far the best repair technique that I could think of I was about to suggest the underpinning and gouging and or dovetailing but yes indeed you are spot on!

[@mr.octopus6972]

Acid wash work very well with vinegar mixed w a little bit of dish soap.

[@mr.octopus6972]

@Oftin Wong .... I don't give Q that I did not test myself. It works !

[@anonymous_friend]

Come back in 20 years and let us know. lol

[@suryaguru3462]

Dude, your talk shop demonstrates minimal experience in this thing... No acid... only a good spray and broom... and a good strong solution of PVA then gets washed onto and spread continuously over the old surface...until it forms a slick on top and has soaked down into the old stuff...filling up cracks and holes etc... then, when still wet, apply PVA/Micromilling (thinset for tiles) to the required level... let it set for a day or more as required... your first coat of PVA and water alone IS REQUIRED FOR SEALING THE OLD, and sticking the new layer to it. I have used PVA instead of steel reinforcements in a Marine environment to prevent corrosion and expansion of steel... 15 years... no cracks at all... it's like infusing liquid plastic into your construct... It does not paint to well...

[@Swimmingpoolsteve]

A concrete worker who does not use acid to clean old concrete before adding a new layer is not a concrete worker I would take any advice from. Thanks for sharing your opinion as to whether I sound experienced or not.

[@theloniousm4337]

yeah you need to be careful with the muratic acid depending on what the application is. You often just move the point of failure deeper into the cement where the acid wasn't properly neutralized. PVA is the miracle drug here - not the acid. The acid can do more harm than good.

[@suryaguru3462]

@@theloniousm4337 Thank you sir...

[@nimajnebrm]

Kudos to you for this informative and targeted video! And thanks for not turning this into a 20-minute rambling video like some KZbinrs do

[@chrismoyler]

We use SBR Styrene Butadiene Rubber, as a bonding agent. It's much more durable and water resistant than PVA, but it is much more expensive. Any thoughts please?? Thanks

[@lloydspro76]

how much sbr to slurry mix?

[@Swimmingpoolsteve]

SBR outperforms PVA based concrete bonding agents for most applications, except for UV tolerance. SBR requires mechanical protection from the sun or else it ends up brittle like an elastic band left out in the sun. SBR also has the highest chance for chemical interaction with other modified mix design, polymers or additives. It really is a deep world for bonding concrete, which is why this is a professional trade. there are limitations to how much a DIY concrete repair person needs to know. If you want to see a litttle more about how deep this subject is I compiled a lot of the information into this article: www.swimmingpoolsteve.com/pages/bond-concrete.html

[@markflierl1624]

In California, we use a bushing hammer to rough up the old concrete and then epoxy in rebar to connect the old to new pours.

[@fbombgarage]

Chemical bond (with acid), grinders will give you mechanical bond.

[@cornflakeusa]

Excellent video. Sometimes muriatic acid isn't possible to use and can be dangerous. You can also scarify the concrete using a grinder with a cupwheel. If you're working inside, a vacuum attachment shroud can be used on the grinder. A slurry of tile thinset mortar can also be used as a bonder between the new and old concrete. It's important that the slurry is still wet when you put the new concrete down.

[@frankvasquez1387]

Is there a minimum cement pour in inches that must me added on top of old cement in order for new cement to properly bond and not crack?

[@kwokshsee01]

*Thank you very much for sharing your wisdom !!!* Allow me to ask: 1. After acidifying the old surface, do you need to wait for some time before proceeding to the next step (wetting it thoroughly)? If yes, then for how long? 2. What is the *ratio of Portland cement: water: white glue ?*

[@Swimmingpoolsteve]

Please read the full article that contains this information here: www.swimmingpoolsteve.com/pages/bond-concrete.html

[@champfox1]

That's how we patch small divots on our state bridges, great job. For large repairs, epoxy rebar into the existing concrete making sure there's the specified rebar clearances.

[@mar4380]

What are rebar clearances?

[@champfox1]

@@mar4380 basically the space between the rebar and the existing concrete and also the distance of the rebar from the outer edge of the concrete. The idea being that new concrete or slurry should surround the rebar at a specified distance. That distance varies depending on the application.

[@ElementalMaker]

Great video! From my understanding diamond grinding the area to be re-coated is superior for bonding new concrete over acid washing. Have you used this method before?

[@Swimmingpoolsteve]

Sure do, especially for tile work but be sure to have a rough grit diamond cup as you do not want the concrete to be smooth at all. The rougher the better for adhesion of the new layer, and this is why there are so many comments in here about pinning, scarrifying and scabbling which are all intended to increase the texture and surface area of the old surface such that the new layer will adhere better.

[@ryanrivera6412]

Would this work on a concrete flat roof?

[@johnbelvin5216]

Not a mechanical bond it's a more of a chemical bond

[@DDEENY]

The terminology that's missing is "bonding agent" and it's commonly available. (I suspect that it may actually be glorified white glue.) It's used by painting it onto clean concrete (critical point of yours) and applying new concrete or mortar to it. I've had good results with it. It can also separately be used as an additive to the concrete's water mix to enhance the integrity of the concrete. (Not as an alternative to applying bonding agent to an old surface.) Another technique for bonding new concrete to old is by scrubbing the new concrete into the surface of the old concrete with a stiff brush before finishing the repair normally. That also does the trick. Great video, thank you.

[@paulmitchell6485]

Yep, multi bond here in NZ. Awesome for tiles or anything you wanna make stick

[@wombatillo]

PVA is not ideal for wet environments but works well for many uses. For outdoor use there are better products which have polyacrylate, SBR or whatever synthetic latexes.

[@JohnBrodt]

After using marantic acid, you rinse with TSP or Ammonia to neutralize the surface back to a neutral PH of 7. Other wise the acetic PH of the surface will interfere with the bonding. Period. Don't forget to neutralize after using Marantic wash solution.

Marantic acid? Ammonia (NH3)?? *Acetic* PH??? Marantic acid, again? My heart...

[@victoreous626]

@ You forgot to inhale deeply during the process

[@JohnBrodt]

@ to much to handle? Then simply just hire a pro....!:-)

[@eekay3646]

I plan on building a brick curb for my shower. My subfloor is concrete. Will thinset work fine to bond them, or is slurry the better agent? Thanks.

[@Swimmingpoolsteve]

I think thinset is commonly used for bonding in indoor shower applications

[@martinanderson2996]

Great advice. I would add, don't let the slurry dry before installing your concrete.

[@swift-o]

True. It seems obvious, but, many people don't even

[@ozarksfarmerhansen8782]

Dumb and dumber if you mix glue with the slurry and let it dry it's not porus any my more nothing to bond to.

[@marktran5076]

Im a tiler, we add cement slurry to bond new cement to old concrete. Similar to this method

[@IndependenceCityMotoring]

Dont forget keeping the new concrete moist/covered for the first 30 days.

[@Swimmingpoolsteve]

Great tip that nobody mentioned yet. Cheers.

[@ethelryan257]

@MARC D. Yup.

[@porthugiz1]

30 days???

[@IndependenceCityMotoring]

@@porthugiz1 Yep, Google "cure time for concrete". And methods to help cure.

[@chrisgraham2904]

That is a fact, but I've never seen anybody do it for more than a few days.

[@tonitouchberry894]

Hi! Is there a "wait" time between the slurry application and the final pour??

[@refaatkhalil1237]

`Yes ; wait one or two minutes until the PVA in the slurry becomes " tacky ".

[@Swimmingpoolsteve]

Specifically no. The new concrete goes on while the slurry is still wet.

[@robertb7362]

Hey Steve. How thicker should the new layer of concrete be in order to NOT crack - considering it’s a driveway?

[@Swimmingpoolsteve]

Are you fixing a hole or rebuilding the structure? With a topping layer I do not believe that you would want to go any thinner than 1/2" but this is called an overlay and is different than fixing a pothole in a concrete driverway, for example. Overlays need to be modified with acrylic latex and I would not want to use a latex modified topping mix with a PVA based slurry like in this video. Better to use an acrylic slurry with an acrylic topping mix...but for overlays, again this is a specialty process and different from patching concrete. I suspect epoxy based adhesives would be the recommendation of engineers.

[@salgonzzo1196]

I've done your method on stucco and it works.

[@michaelgrosso7891]

Most informational video I've seen yet on concrete bonding old to new... thank you

[@Rajiihammr]

How does KZbin (Google) always seem to know about things I'm THINKING about doing? I haven't even done a search, 'sides I use Bing search. Spooky ;) Thanks for the succinct video!

[@Swimmingpoolsteve]

We live in the matrix...there is no denying this!

[@hank0455]

In most cases the concrete is beyond repair, fixing it would be temporary. The concrete beneath your patch job will most likely continue to deteriorate. A home owner can only hope it can be fixed, but your method is probably there best chance at prolonging the inevitable.

[@fergferguson7370]

Good info...but some visuals with your narrative would be outstanding ...think about it Steve ..you will go from good to great

[@Swimmingpoolsteve]

I have the link in the description and also in a pop up window during the video, but here is the visuals you are asking for: kzbin.info/www/bejne/enKQl3aIh92Medk

[@clydejuriansz6646]

You’re a good teacher! Clear instructions and repetition. Great video. Thanks

[@rossmiller4228]

I'm just curious. I need to pull out all of the stops on my driveway. House built in the '50s that I bought 18 months ago. The driveway has lots of issues. A downsloping street that feeds into my downsloping 900 sq. ft. driveway, towards the garage door, with a small 4-inch drain, in front of my garage door. The previous owner obviously spot patched it several times but there is presently a lot of cracking that needs to be dealt with. It's been a rough winter on this driveway. 50 degrees one week and subzero the next. Having it replaced will run $7,000 to $10,000 that is not in my budget. I'm wanting to resurface, filling cracks and surface grinding, with a polymer modified resurfacer and then staining at a cost of between $400 and $600. Probably not a permanent fix but hopefully something that will get me by a couple of years. I am concerned with the resurfacers ability to bond with old cement and the previous owner's patchwork. My question is, "will a dollop of white glue mixed with each bag of resurfacer assist in the resurfacers ability to bond with old cement and old patchwork"? Thanks for the great tips, you obviously know your stuff.

[@Swimmingpoolsteve]

This video talks about a very basic and easy concrete bonding method that the vast majority of people will have success with, however your problem really is a little more involved than fixing a pothole in your sidewalk. For your job I would TSP wash everything to pull oil that must surely be there, then I would rinse, then acid wash, then TSP again, then rinse, then I would bond with the latex Bond-Crete from Larsens and be sure your topping parge is not a fast set product. The chemical bond will be stronger with bond-crete which is good because it sounds like you actually need a new driveway and at least this way you should have every chance to get the best bond possible.

[@rossmiller4228]

@@Swimmingpoolsteve Thanks very much for your quick reply Steve. I will track down some Bond-Crete. I truly appreciate your videos

[@johnniethepom2905]

If you're in Australia Google Weldcrete , the best additive I've ever used .

[@johnniethepom2905]

@Event Horizon , In WA they manufacture it at 200 Star street , Welshpool , Perth . So strong it will stick sand in the bottom of your bucket . I've used it to repair Dummy floor screed , strengthen mortar and tile adhesive . If your project has any Cementatious ingredients use Weldcrete . Be sure to clean your tools and mixer straight away as it a devil of job if you leave it for half an hour.

[@theresachiorazzi4571]

I always heard that this ever works. But nowadays it’s possible products can make it happen. I like your theory.

[@crucifyrobinhood]

Back in the 90's I often did exactly as Steve explained, sort of. I would make a mix of Burke bonder (or Dymalite, depending on the color I was looking for) and water and saturate the concrete. Then I would put dry Portland in a burlap sack and "slap" the prepared surface leaving a thin layer. Spritz that layer with more Burke and water and repeat. When the coating was thick enough I left it alone for a few then buffed it with the Portland bag as it went off. The final finish shined like a freshly sealed shop floor with an eye-catching swirl pattern. Haven't thought of that in years, thanks. Subbed.

[@donsherman9522]

Very good informative video ....& no stupid rapp musics playing...thanks you sir

[@gloriahernandez7107]

Hello does this work for a concrete pool?i was told to add mortar before applying the glass tile on the top of the pool..Thank you

[@Swimmingpoolsteve]

It would work better than nothing, but for under water you should not use PVA, but instead use latex acrylic to make the bonding slurry, like in this video: kzbin.info/www/bejne/enKQl3aIh92Medk

[@sethtorres407]

Could I substitute the bonding slurry for thin set?

[@samlair3342]

Usually, a talking head approach is not effective; however, you made it work. You explained it so well in a forward moving yet repetitive fashion that it stuck!!!

[@KoalityofLife]

Might be a stupid question but here goes. Do you pour the new concrete over the slurry right away or wait for it to tack off a bit or dry? Thanks in advance. :)

[@fortyoddyears5295]

Someone said above do not let it dry. Pour on after tacky.

[@KoalityofLife]

@@fortyoddyears5295 Thank you. :)

[@fortyoddyears5295]

Your welcome! Another said said immediately while still wet.

[@frankhoffman3566]

On my own I came up with a similar method that worked. Of course clean the old concrete thoroughly (I used only water and a wire brush). Wet it down again. Mix your wet concrete and slurry at the same time. The slurry is a liquidy combination of portland cement and water. Apply the slurry to the old, wet concrete. Then I vigorously WIRE BRUSH the slurry into the old concrete, in essence, trying to force the slurry into its pores. Pour the new concrete immediately, before the slurry shows any signs of drying. This worked for me under some pretty severe flooding conditions - no failure or delamination. Glad to hear I wasn't too far off in my method.

[@davestrasinger8176]

Excellent video, perfect for the layman or experienced contractor alike, don't miss a step here. This is critical for any concrete fill work where you have to add new concrete to existing. In my case, during initial foundation plumbing pipe-set for a slab, the plumber missed a few floor drains and set other pipes in the wrong place, so when it came time for plumbing rough-in, The plumber had to break up a lot of concrete. This video was perfect for detailing how the concrete should be replaced in those holes to ensure a strong bond and continuity.

[@huggybear539]

So... do you let the slurry dry then concrete? Do you dry it then wet the surface to concrete? Do you pour concrete over the wet slurry? Wassup?

[@Swimmingpoolsteve]

Pour directly on the wet slurry. Since you soaked the base layer with water already the slurry will last a good few minutes to allow the new concrete to be applied. Dry is death for concrete bonding and that goes for the base layer, the bonding layer...any of it!

[@gunner678]

I was going to say, PVA white glue every time with concrete...works a charm!

[@benth162]

So you've boiled it down to 80+% bond eh? that may be fine if you are doing no more than sidewalk repair, but anything else, that 80% is not good enough and the reason you don't see highways being repaired like you show. Workers must cut out a whole square or rectangle, fit it with more rebar and the like and then pour it almost dry with a very low slump. I would like to see your method proven that it does not create a "Cold Break".

[@Swimmingpoolsteve]

Fortunately most home owners do not need to know how to bond a highway surface to an old highway surface. I would hope that professionals would be the ones doing concrete repairs like that. Other than professional commercial and industrial concrete applications this advice is very useful for home owners who do not understand the basics of how to bond new concrete to old concrete. If you would like to read the full article it talks more about the difference between structural concrete repairs and DIY level concrete patching, and how home owners should never attempt to repair anything structural. www.swimmingpoolsteve.com/pages/bond-concrete.html

[@benth162]

@@Swimmingpoolsteve Great reply, thanks for the link.

[@dizzydinonysius]

The surface can then be prepared using one of a variety of methods, including acid etching, sand blasting, shot blasting, scarifying, or bush hammering. In most cases, the rougher the prepared substrate, the better the bond. Two kinds of polyvinyl acetate (PVA) bonding agents I know of are re-emulsifiable and non-re-emulsifiable. White and Yellow Carpenter's glue respectively. White is not recommended for outdoors or damp situations but even Carpenter's glue is not exactly impervious to water either and is only "resistant". That said, I use acrylics, SBR, latex-modified, or epoxy depending on the situation and would never advise otherwise. It is more important to me to have a product designed for that use and with a proven track record.

[@danielfronc4304]

You didn't specify the relative proportions of water, Portland cement and Weld-Bond. Could you please throw us a bone re: the proportions (ie. is it 1:1:1 ?). Thanks.

[@dukeman7595]

Mix it until you have a slurry, such as a thick milkshake and apply with a paintbrush.

[@ensignj3242]

In a different video, Steve says the slurry recipe is: first mix 50% water with 50% glue (or Weldbond, etc.). Then add enough Portland to make a thick milk shake consistency. Also, keep it covered and in shade because it sets up fast so use it quickly.

[@Swimmingpoolsteve]

Here is a video where you can watch me making a slurry and see the proportions: kzbin.info/www/bejne/enKQl3aIh92Medk

[@larz101a]

I agree with everything you say, however as to PVA glue (white glue) there are two types one is of which is permanent set or waterproof, for use in heavy water saturation applications, the other is water soluble that will deteriorate when wet.

[@amjadmalik7285]

...so which one to use?

[@rockyfjord3753]

I want to apply an aircrete sprayed on to cinder block house exterior. I assume all the conditions you outlined apply to sprayed on aircrete as well. My only question is that if I apply a slurry plus bonding agent over the clean cinder blocks, it will have dried by the time I am ready to spray on the aircrete [as a faux stucco]. So should I wet down the slurry coat, and is that possible without it then running off the cinder blocks?

[@gregkrueger7013]

I've done concrete restoration. For best results saw cut your concrete so there are no feathered edge's. Good luck.

[@Swimmingpoolsteve]

That is a great tip that anyone new to working with concrete will probably not know. Cheers.

[@smartchip]

Could you explain to a novice, what exactly would you do?

[@gregkrueger7013]

@@smartchip You have to get i minigrinder. 4" with i diamond blade. Square up the patch around it with a cut. Then take a hammer and chisel and from the inside of the patch hammer bake to the cut.Remove all the debris and clean the patch.Then follow all the steps in the video. I hope this helped. The patch will be much stronger.

[@smartchip]

@@gregkrueger7013 much appreciated,

[@katrenco]

@@gregkrueger7013 Thanx for the explanation....I had no clue what it meant. Much appreciated.

[@imeetrance2691]

Will this process guarantee water seepage from going thru in between the new & old concrete? I've had experience that in time, there will be cracked hairlines along the new bonded concrete, esp. in moulded concretes. This is evident even when we've applied putty and painting over the bonded areas. Water seems to find a way thru in between the gap...

[@Swimmingpoolsteve]

it will not guarantee water seepage. If you have a wet application with water that soaks through and moves through the area then this application for bonding will work, but likely won't last. The grade of bonding agents known as acrylic latex or even SBR latex would be much more resilient to the ingress of water. I think you should read this article that talks about these other wet applications options more: www.swimmingpoolsteve.com/pages/bond-concrete.html

[@BurtBowers]

Something I never knew I am more educated now to this thanks👍

[@Swimmingpoolsteve]

I am happy this was able to help you - cheers

[@The78bluedevils]

Weldbond comes in two types. for wood lower cost. the one for bonding has a higher price. made in Canada in 3 liter size & 14.2 fl. oz. This the one you want "Steel Tough Weldbond Universal Adhesive on label. check Amazon for best price. using it since 1998

[@michaelsolosky53]

Really well explained and thought through. Thanks Steve for being crystal clear

[@Swimmingpoolsteve]

Thank you for commenting. Cheers.

[@LTVoyager]

I need to raise a couple of low spots in my garage slab where the contractor apparently got low on concrete and thus my center drain is higher than a couple of spots a few feet away from the drain. They pool about 1/2” of water so I just need a thin patch to raise these areas. Is thinset concrete mix suitable for this on top of the bonding slurry? Or is there a better formulation to make a 1/2” patch that will taper to nothing and still be strong enough not to break up under the weight of car tires?

[@Swimmingpoolsteve]

Thin set is not the right patch to use, but if you DID use it then you would definitely not use a bonding layer of any kind. Thin set is possibly the most heavily modified mortar product on the market already and will bond to concrete, overhangs, wood, glass, your hands, pretty much anything...but it is not UV stable, and will discolor and not finish well (it will be rough). The challenge for you is that what you are doing is not so much bonding new concrete to old concrete like you would have with a pothole being fixed. What you are describing falls under the technical application of an overlay. An overlay is where you will have concrete 1/2" or less in thickness over another concrete substrate. This will require special surface prep, primers, bonding agents and a heavily modified topping mix. Any other solution than this route is very likely to have the concrete patch shaling around the edges. I am sorry that I do not have your answer, but hopefully this will point you in the right direction. I am not a flat work specialist - I am a structural concrete specialist as well as certain decorative finishes and plasters. What you need is info from someone who only does overlays and parge coats. Cheers and good luck to you with your project.

[@seahippies]

'White Glue' dude is Poly Vinyl Acetate or PVA (wood glue commonly)

[@Swimmingpoolsteve]

Thank you.

[@chrishope9268]

I use PVA all the time .I'm going to add fiberglass to a 50mm slab

[@katrenco]

@@Swimmingpoolsteve I'm sure alot of ppl, like me, appreciated the "white school glue" description/name. Everyone knows what that is, not everyone knows what PVA glue is. PVA sounds way more hi-tech and expensive than school glue. So, thank you for the plain, simple descriptions that are easily understood by everyone.

[@wjaillett]

So would you use the quikcrete Portland cement and glue first then mortar mix or whatever on top of that? How long does the Portland need to set before second step? This area is by my pool. Thank you

[@rickysmith2248]

What's the mix ratio between porcelain glue and water?

[@Swimmingpoolsteve]

This video shows me making a slurry: kzbin.info/www/bejne/enKQl3aIh92Medk

[@jdog4534]

Im down with your process here, but is it a "mechanical" bond? ..or a chemical bond? When I think of a mechanical bond, I think fasteners/hardware that must be manipulated with tools, not just smeared into the issue. I don't mean to troll on you here, I really don't know the correct term. Where did you learn that it's a mechanical bond?

[@Swimmingpoolsteve]

The person I learned this from was a civil engineer who spoke english as a 7th language, seriously, and I also doubted the terminology. What I found was that for cementicious bonding purposes, a mechanical bond is described as: "a mechanical bond is achieved by the penetration of the bonding material into the pores of the old surface, forming a mechanical interlock". It is not just the chemical interaction of the bonding agent which enhances the adhesion of new to old, it is this mechanical process of water ingression into the old surface with the bonding slurry, which then creates a mechanical hold with the new application of concrete. Cheers: link.springer.com/chapter/10.1007%2F978-1-4615-8312-7_6

[@jdog4534]

@@Swimmingpoolsteve wow! Thanks! I felt like such a troll when I posed the question but I'm really glad I did. This info could be very valuable when dealing with some of the issues and the inspectors who'll ultimately have to sign off ...Thanks for taking the time to set me straight... I'll go "mash" that subscribe button now. Cheers

[@jdog4534]

@@Swimmingpoolsteve oops! I was already subscribed

[@pandapanda8354]

I had to look ALL OVER for this info. THANK YOU! Seven to one muriatic acid and then dampen down and then bonding slurry. Ugh! You’re the only one giving these steps in an easy to follow steps. THANK YOU

[@Swimmingpoolsteve]

After acid you wither need to wash it like 10 times to neutralize the pH, or just wash it with TSP after acid washing it and this will stop the concrete from being super acidic which would likely cause a patch failure some point in the future

[@arturturk5926]

I am a contractor, you killed it Steve, well done! SwimmingPoolSteve born from ScubaSteve?

[@nickpeterson6647]

Pro Tip: just before cement patch hardens, be absolutely certain to scribe it with your initials and the date as well as the initials of your crew members.

[@palipali4264]

I would be pissed if a contactor did that childish crap to a slab I paid to have installed.

[@daveclelland1188]

P. Chretien Take it easy Bobby...it’s called “sarcasm”!

[@russianbot4418]

@@palipali4264 Odds are they are already screwing you over in some way so you might as well let them tramp stamp their initials on your ass while they're at it.

[@rickb4806]

@@russianbot4418 Like the company that poured a concrete slab to widen neighbors driveway? They placed a 6" x 6" wire mesh on top of the stone base. I watched from across the street thinking " I bet they won't lift the mesh to middle of new pour..." Answer...of course not. Signed engineering tech.

[@marioparra78]

i like seen old date on concrete

[@copernicus633]

Nice and concise, without tons of extraneous yak. How few do that !

[@TRICK-OR-TREAT236]

THIS SOUNDS DANGEROUS ! DID YOU SAY ACID ? THINK I'LL JUST GET THE WIFE TO DO IT.

[@teresahopewell8207]

Great video. Question... I have 2 steps in my front of the house and the same section always breaks apart. Will this work. To repair a step? By the way the steps are field rock.

[@robinkemp1261]

Very well explained. Thanks for sharing professional information.

[@Swimmingpoolsteve]

I am happy this info was helpful for you. Cheers.

[@Technologyadvisor1]

Regarding concrete i just put down a new slab of concrete for a pond but its not very level 3 days ago can i add more as its very new?

[@Swimmingpoolsteve]

The concrete is still green for about 30 days, and the newer it is the more readily it will accept a bond with a new layer being poured on top. Still, anything past one day I would use the bonding layer. For a pond I would use this bonding slurry specifically : kzbin.info/www/bejne/enKQl3aIh92Medk

[@gime8148]

And drill some pins into the existing concrete for better adhesion

[@Swimmingpoolsteve]

Certainly for anythign structural or appreciable in size this is a good plan

[@rickb4806]

Dowels. Esp outside 6" min.

[@slowstang88]

That's what I did for a broken section of curbing at the end of my driveway, 6 inch masonry screws driven in a couple inches, and 2 foot rebar driven 1 foot down as well as stainless mesh safety wired to the screws and rebar

[@TheOGPoohBear]

@@slowstang88 Could you send me some before and after pics. I'm dealing with a broken section of curb at the end of my driveway too. On a slated hill so the rain water tears up the already eaten away curb.

[@slowstang88]

@@TheOGPoohBear I didn't take pics, sorry. Just make sure anywhere you are trying to adhere concrete to already set concrete you scrub it really well and keep it wet before, during, and after and it will have a better chance of adhering.

[@rrandor1]

what if the new and the old concrete are vertical posts for concrete block construction and both posts have rebar? Do you expose the rebar in the old post and tie the two posts together with steel wire? Or do you drill holes in the old post, clean the holes of dust, fill with epoxy and insert steel rebar? Or do you just rely on this slurry technique? Or any or all of the above?

[@nlo114]

Scabble the surface, flush the dust with plain water, dab treated surface so it is only damp, then apply new concrete. No chemicals, no corrosion, no nuetralisation worries.

[@joyo2122]

Thank you man

[@matalimanaito6341]

i agree with your advice. An uncle of mine plastered over hollow tile and it's lasted 40+ yrs. with polyvinylacetate

[@GDISinc]

I followed your instructions but found out I’m going to need another coat of Crete because the hole was to deep for one. Do I need to apply your slurry onto the second coat? Thx!!

[@Swimmingpoolsteve]

If the concrete is hard, and you want to add new concrete, then yes you in theory need to bond the layers. However it is worth noting that for the first 30 days concrete is "green" and still curing, and additional layers would likely bond better to this than concrete which is already aged...even without a bonding slurry being used. To be safe I would use one.

[@robeggett9946]

Excellent job on this video. Clear, concise, to the point and no BS or comedy attempts.

[@clebertormes6900]

Preciso de uma receita pra fazer blocos de concreto leve, tem algum vídeo pra me indicar?

[@Mr.E.Shoppa]

You're talking more "chemical bond" than "mechanical bond" when it comes to cleaning surface

[@Swimmingpoolsteve]

Mechanical bond is actually correct as I describe it in this application as it refers to the bonding agent absorbing in and throughout the old concrete which when hardened creates an interconnected gridwork of mechanical connections. There is chemical bond as well from the acrylic / PVA but the mechanical bond is the source of strength between layers. Are you familiar with mechanically interlocked molecular architectures? MIMA's is a mechanical bond, it does not just mean physical things like wire or steel. In mechanical bonding the adhesive flows into the surfaces of the adherends and anchors them together once it has solidified, using an interlocking effect.

[@purplelizardtoes]

@@Swimmingpoolsteve Well said, and so respectful and considerate! You, sir: gentleman and a scholar confirmed!

[@larslover6559]

Binding old concrete to new..I drill holes and hammer in rebars(referred to as dowels). You can use thinset (glue for tiles) around the rebar to make it stick better. I notice though that a small crack appears between the xoncrete after some time but the dowels will keep them bonded together. I wouldn't just trust in the slurry solution without rebars to connect the old and new concrete..

[@Swimmingpoolsteve]

This is actually a great process, but of course it depends on the concrete repairs being done. I can tell you that from my experience, and the engineers that I have worked with, the product of choice for setting dowels is not thin set, it is specifcally "non shrink grout" as almost all forms of concrete and mortar shrink when they cure. This one does not and this is how the dowel will hold securely long term. Thin set will hold it short term, and maybe long term, but non shrink grout is the "correct" product for that specific application.

[@joeygagliardi7380]

Well Done, I now can tackle my project with confidence. Very good Description of all contents needed. thanks and have a Great Day along with a high 5, and 2 thumb's Up!!

[@addismegenagna4780]

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[@AtomicQuotient]

Awesome video. Sounds like thoroseal

[@randyferguson6764]

The new old school look = respect,Steve. Your videos are solid !

[@Swimmingpoolsteve]

Thank you :)

[@stoker20]

Portland is the official name for cement???

[@rossmiller4228]

You make a great video sir. What are your thoughts on Weld-Crete as a bonding agent?

[@Swimmingpoolsteve]

Its great. That is a modified PVA (white glue) based bonding agent and could be used as described in this video. Cheers.

[@paulbolton7232]

I thought pva remoulsified in damp conditions is it not better use a sbr . Thanks