Damp concrete floor repair | concrete tanking

Here we tank a concrete floor that has no physical damp proof course. Tanking the floor is a great solution that is cheap and will prevent any dampness from rising up through the floor. In this example KA tanking slurry was used which costs about £25 for a 25kg tub. Brought to you by www.ultimatehan...

[@AbuYussuf]

Can I do this by my self or I would need to hire someone to do it? Because I have serious damp problem in my living room, it already destroyed twice my sofa and it is worse in the winter. How to mix the stuff together, what percentage?

[@ultimatehandyman]

Yes, you can do it yourself. You have to mix it according to the instructions on the brand that you buy. I used KA tanking slurry for this kitchen floor, then applied a screed over the top of it. kzbin.info/www/bejne/eXOko3mqq8qNpqs

[@AbuYussuf]

Thank you very much, greatly appreciated

[@jimmyzoom1143]

If this was a limecrete floor this problem wouldn't be happening

[@daddyxtc]

Alternatively can you recommend a suitable self levelling compound.

[@garnhamr]

moisture tolerant like arditex NA, stopgap 1200 pro, level it 2 etc for damp situations.

[@LeodisFightingChampionships]

Hi mate, great video... Just pulled up my subfloor as was wet as anything. Going to put some KA tanking slurry before replacing the subfloor. Any tips for getting the surface nice and clean before applying? I've read about pressure washing but don't want to flood the whole room. Cheers mate

[@jpatel4585]

Will tanking slurry completely stop water seaping through the concrete floor in the house? There are damp spots appearing in random places on the carpet and there are no water leaks from pipes around the house. Not sure if this from bad damp proofing of a propert built 20 years ago. You help appreciated. Thanks

[@ultimatehandyman]

Yes, it should stop any damp from coming up through the concrete 👍

[@Guide504]

K A is a serious industry secret, it is incredible done correctly and I have use 3 other brands. It is also resistant to UV which if your using it under cladding is useful during construction if it has to be left uncovered for a time.

[@ultimatehandyman]

Thanks for the comment 👍

[@mattlewis7107]

I live in a terraced house on a slope and have (i think) penetrating damp as the one corner of the room is around 24" underground. I have chipped back to the render and the render gets discoloured it it rains and really damp if it rains heavily. The whole house is underground by this depth along the right side but I've had no issues in the back reception room, just the corner of the front room. It was built in 1875 and obviously if there is a slate course there (not checked) it wouldn't prevent penetration. Is this stuff any good for painting onto the interior brickwork? External tanking isn't an option as we go straight onto the public path outside.

[@ultimatehandyman]

Does it have a cavity wall? If it does, then cleaning out the cavity might be an option- kzbin.info/www/bejne/rnTRhneYorCgnbs I believe you can use this tanking slurry on walls, but I have never used it myself yet. I'm sure I have a tub of this somewhere, which was left over from this job. If you live anywhere near me (Darwen, Lancashire), let me know and I'll check to see if I still have it. If I can find it you can have it, as long as you collect it. Thanks for the comment

[@TheDidee73]

Where in MI can this be purchased please ?

[@ultimatehandyman]

Diane Parish Not sure, sorry. I'm based in the United Kingdom. Your local builders merchants should stock something similar.

[@womblestacker7993]

Will that stop damp coming up got same problem in my bungalow concrete floor

[@Dragon-Slay3r]

😂

[@maxny1]

Does anybody know what this product is called in the US?

[@spendtimesavemoneydiy]

Nice video thanks! This is probably what I will have to do in my garage/workshop! Can you also apply this to the walls as part of the walls are below ground??? 👍🏼

[@ultimatehandyman]

Yes, as far as I am aware you can apply it to walls below ground. Thanks for the comment

[@freesnow49]

Can anyone reply please. Can I do this and laminate over it . ? Obviously I am going to put underlay. But is it ok to apply this and laminate over . Thank you

[@ultimatehandyman]

Yes, it should be fine. Just ensure the tanking has dried before you put the underlay and laminate down ;-)

[@freesnow49]

Ultimate Handyman thank you

[@MrNothingSoFar]

Hi, I used the same KA-tanking compound on the floor in my kitchen about 2 months ago. The result is literally spotty. Some parts of the flow are now bone dry, but there are spots that are still dump. Not as dump as before but above what I would consider dry. Before humidity went off the scale of the meeter I use (above 33%). Now it is about 25-20%. I wetted the flow before applying the slurry to facilitate penetration of the tanking agent. Any experience with this sort of issues? Thank you.

[@AngelGonzalez-mt6sj]

MrNothingSoFar

[@amywild7758]

Thanks for the quick response. I spoke with KA their guys said it was fine to do that but recommended breaking the tiles up to give the slurry something to bond to as well as adding an SBR for flexibility. Thanks for your help.

[@graemeturnbull8422]

hi great video, did the one tub of slurry cover the whole garage floor? was it also possible to do the 2 coats out of the one tub? thanks

[@marcogarofalo6343]

So where does the damp go once you've applied this slurry?

[@ultimatehandyman]

It stops beneath the screed. Thanks for the comment

[@franklotion8]

Im glad you hit that corner..that was buggin me..lol..nice job brotha👍👍

[@ultimatehandyman]

Thanks for the comment

[@daddyxtc]

Appreciate your guidance. Last query, how long should I wait before applying Pro50 levelling compound? There will be some ventilation from a small window.

[@michaelsedgley4949]

If the concrete is damp would using a dehumidifier be the best thing to use prior to any tanking treatment.

[@anajohnson4993]

Hi there.Just came across your video and thought it very interensting...I'm having a problem with my garage where whenever it rains a lot I have water coming in, not from outside but I guess from underground...Can I use your concrete tanking to solve the issue? Thanks inadvance for your reply :0)

[@brido88]

Did you ever do this? I am about to try with the tanking slurry!

[@letsplayskatch]

@@brido88 Did you gave same problem with your garage floor? If so how did you get on?

[@PaulW1954]

HELP ... suggestions for negative pressure damp and some water penetration on my single brick garage wall which neighbours raised path is aprox 15 inches up against the wall ... Thank you.

[@martyboywex]

i have a bedroom with no dpc u derneath, i put 3/4 ply down to level the floor last year not knowing there was no dpc. can i apply this stuff then re lay my levelling fillets and re lay the new ply and be confident its sound?

[@ultimatehandyman]

+Martin o connor Yes, you should be able to. Just check the manufacturers instructions on the container when doing it as the instructions might be different. Thanks for the comment

[@daddyxtc]

I suppose that was a novice question but was just curious about the dry concrete. Cheers

[@lukepjd]

Hi mate, great videos by the way! ;) what would you suggest putting on damp quarry tiles before all new carpets? Any help much appreciated

[@ultimatehandyman]

+Luke Davenport Thanks, it is not something I have done to be honest. You might be able to put a damp proof membrane down (glued to the quarry tiles) then underlay and then carpet on top. I'd check with the carpet fitter as he should know if this is the correct thing to do or not. Sorry I can't be of more help ;-)

[@rstradt]

What would you call this product in the U.S.?

[@ultimatehandyman]

+Robert Stradt I'm not sure, sorry. I have tried searching Google but it keeps redirecting me to the UK website! It's called Tanking slurry over here!

[@rstradt]

Thanks, I know there must be something here. I just don't know how to find.

[@mimithomason7815]

@@rstradt hi there, did you manage to find it? i have similar situation . maybe and want to know what can i get in the US? thanks

[@MrTrustafox]

what is the purpose of it? if it is cement based is it not just the same as the concrete floor? and wouldn't a thin covering crack and peel?

[@marksellers6664]

Hi there, Just wondered with KA tanking slurry can it seal a basement which has a small water flow in and stop damp?

[@daddyxtc]

Sorry, what I meant was to get some PVA on the dry parts of the concrete floor before applying the slurry. I've got 2 tubs coming tomorrow for a double coat in the cellar

[@HouseFairyDIY]

Hello. Would you know if this could be applied onto damp quarry tiles to enable the floor to be self-levelled and then tiled? I don't want the self leveller to delaminate and the tiles to pop off.

[@ultimatehandyman]

I'm not sure, sorry. Your best bet is to ask the manufacturers- www.kabuildingproducts.co.uk/contact_us.html Thanks for the comment 👍

[@DC-rs6bi]

This is great vid I'm a DIY enthusiast 😒😅building a splash pool ,as the concrete base is at the level of the water table ,in one corner its holding a little bit of water ,I'm tanking the whole base using this stuff adding sbr ,behind the blocks the face giving sand cement scratch coat another all round tanking with this stuff, pva then finishing with marblite pool plaster HOPEFULLY 🤞keeping ground water out and pool water in 🥴🤞 ..I'm also putting a sump hole in that corner and French drain for extra piece of mind 👍

[@ultimatehandyman]

I'd be careful with PVA- it turns back to PVA when it gets wet.

[@alcapone9487]

Please can you help I have had damp course done to the walls however the concrete floor is still a bit damp I was thinking of painting the floor with DPM paint should i do that or not ?

[@ultimatehandyman]

Not sure about DPM paint. In my other rental property, I had asphalt put down by some specialists, they bring it on a wagon and it's boiling hot- they pour it on the floor and let it set. Then I used this tanking slurry in my other property, which seemed to work.

[@daddyxtc]

Not all my cellar floor is affected by dampness. Therefore should a cover of PVA be applied???

[@voice.of.reason]

Wouldn't it be better to dig a trench around the house to take the damp away? Take the soil level down below the floor so the damp won't rise up anymore?

[@ultimatehandyman]

I'm afraid that would not work. You also get rising damp on internal walls! Thanks for the comment

[@ranat5526]

You probably will need to do the walls upto 1.5 /2 mtrs as Peter Ward would say a sealed floor would make for damp walls!

[@ultimatehandyman]

🤔

[@amywild7758]

Hi, I have used tanking slurry before, but i was unsure if it could be used on floors. Would you recommend applying it on top of a quarry tiled floor that has minor damp problems as my budget wont allow me to replace the floor

[@DanielHudson-ShinobiCorp]

Amy Wild I have same issue did you ever try it?

[@kevinsmith3638]

How can you judge the right amount of powder by using a trowel it cant say that on the tub surely?

[@ultimatehandyman]

I don't think it had any specific quantities mentioned when mixing, but you can check your instructions on your tub, as it might be different Thanks for the comment

[@amazing451]

Would a self levelling compound be used after this slurry then? Many thanks for your videos there great.

[@ultimatehandyman]

Yes, I used some that I bought from Screwfix- kzbin.info/www/bejne/eXOko3mqq8qNpqs Thanks for the comment

[@michaelrotsa2575]

Was a primer used to bind it and create a tacky surface prior to using the slurry?

[@MarkoKenyon]

You can tile over it after 24 hours with a normal tile adhesive.

[@dathanb]

Does this work in countries with heavy snow falls like Norway?

[@ultimatehandyman]

I'm not sure. In the UK it is used when a concrete floor in a property, has no physical damp proof course installed. It prevents moisture from passing through it.

[@TheArtist8077]

Hi will the moisture not just go sideways into the walls?

[@ultimatehandyman]

That is a possibility, if there is no damp proof course. Thanks for the comment

[@deanj6969]

What does the tanking do does it stop moisture from raising ? And why is it different from self levelling

[@ultimatehandyman]

Yes it stops moisture from rising up through it, you can then apply a self leveling screed over the tanking once it has cured.

[@george78779]

Do I need to put SBR first and then tanking?

[@ultimatehandyman]

It depends which tanking slurry you are using. The one in this video did not require SBR 👍

[@Guide504]

Wet the floor ....the substrate should be saturated as per the instructions prior to aplication to promote crystalline lattice back into the concrete not just on the surface.

[@ultimatehandyman]

I don't recall it saying I had to wet the floor in the instructions, it either was not there, or I missed it. Thanks for the comment 👍

[@Guide504]

@@ultimatehandyman hi dude, yep just done 58sqm three days ago, it was a a pain trying to keep the slab damp. It was a dry as a bone c35 and thirsty like nothing else. KA is the best slurry I have come across but it needs to be live for both coats and back into the wall or floor.

[@tommmmmer]

is this similar to tanking in the bathroom? like "tank the walls"?

[@GarethEvansmusic]

i have a stone slab floor which has a couple gaps, should i put cement down first in gaps ? also by basement is large , does all the area have to be covereds in one go? or can you wait for say half to dry

[@donnapatterson1500]

Gareth Evans

[@alcapone9487]

Hi mate thank you for this video roughly how long does this stuff last for ? Also when applied and dried will damp eventually seep towards walls ? seen some other videos where bitumen has been applied to concrete floor then over the years its has seeped towards the walls ? any idea please

[@ultimatehandyman]

Not sure, I sold the property after a few years as I was sick of being a landlord. As long as the walls have a damp proof course installed, I think it will be fine.

[@InternetBlowing]

will this work any better then blackjack dpm ?

[@mrjportman]

Found this video really useful. However, I have a layer of moisture on the dried KA Slurry surface on my cellar floor since putting it down? Could this be coming from the air brick with regards to warm air coming in, and then condensing on the cold floor? I'm thinking of covering it up for a period of time to see. Any ideas gratefully received?

[@ultimatehandyman]

It's common for water to condensate on the slurry as the condensation cannot penetrate it. It is probable that the floor is the coldest part which is why the condensation is forming. Does the air brick lead outside? I would have thought that an air brick would help to remove the condensation rather than cause it?

[@Andrewamy29]

jamie portman sees

[@Niall-Noigiallach]

Hi! I laid a plastic damp proof membrane on my concrete slab prior to putting in a screed floor in my steel shed. There is one patch where it seems to have failed and just wondering if you could recommend anything like in the video to fix it rather than breaking up the screed floor? Thanks!

[@ultimatehandyman]

I think you can get a Liquid Epoxy Damp Proof Membrane, which is mixed in two parts and painted on. Or you could tank it and then apply a screed over the top of the tanking!

[@Niall-Noigiallach]

@@ultimatehandyman great! thanks a million for your help

[@mohammediqbal9136]

A quick question please, I have got dampness in my breeze blocks build shed. I did put in a dpc course which is one block above the concrete floor base, do I start to drill holes on the block above the dpc course block please advise. Thanks

[@ultimatehandyman]

Not sure about that 🤔

[@mohammediqbal9136]

Hi, Thanks for the reply. Been informed by DryBase that the rods used for damp proofing are only made for Bricks and not Breeze blocks. Please can you please help how to solve the damp issue. Thanks.

[@ultimatehandyman]

@@mohammediqbal9136 You need to find out where the damp is coming from. If a DPC was installed, the damp must be coming from somewhere else (not rising damp)

[@officerdibble656]

Is this the same as using Synthaproof

[@ultimatehandyman]

No, that is Bitumen based, I think this tanking slurry is cement based. They probably do a similar thing though. Thanks for the comment 👍

[@Georxs]

Hi there, can you paint epoxy paint over the top of this, checked the internet and there is nothing really on this. Any help is very much appreciated

[@ultimatehandyman]

I don't think you can. this product is designed to have another surface on top of it, such as floor levelling compound or tile adhesive etc. Thanks for the comment 👍

[@brido88]

My understanding is you should be applying the tanking, then a self leveling compound screed, then you can paint epoxy onto the top surface of screed.

[@eleanorcook2342]

i have a damp area at one end of the lounge where the carpet is now constantly damp and smells, would i need to take up all the carpet and cover the whole lounge area or just where its damp, its a really old house and there is no damp course, will the damp though try to move somewhere else to get through, thank you hope this is not too stupid a question

[@ultimatehandyman]

Eleanor Cook It depends. To be 100% certain it's best to remove the carpet and do the whole floor as it's unlikely that there is any form of DPC under the concrete. I guess you could of course just try the area where the problem is but I'd go past the area by a good foot or so in each direction.

[@jimmyzoom1143]

Eleanor Cook look into a limecrete floor..

[@marksellers6664]

also can I use it on the basement walls and floor?

[@liamthornhill5122]

next time you apply a tanking slurry make sure to dampen the surface before hand

[@ultimatehandyman]

👍

[@cocospops9351]

Eh it was damp. That's why he did it in the first place 😉

[@kezadrone]

Did this for a week on walls that had to be pointed first had to get round pipes and all sorts, was murder.

[@ultimatehandyman]

I can imagine! Thanks for the comment

[@InternetBlowing]

ok great thanks alot, i will join your forum for more :)

[@magicadespell56]

Is this thin set self leveling cement? I have a pretty decent floor in my basement few cracks I need a mostly cosmetic fix. (lots stains) I put peel and stick tiles they lasted 16 years now coming loose- was wanting to just pour new cement over the old and stain it..

[@ultimatehandyman]

No, this simply stops the damp from coming through the existing concrete floor. I did level it afterwards though- kzbin.info/www/bejne/eXOko3mqq8qNpqs

[@donnapatterson1500]

Shelly Block

[@petersalmon4203]

I've used KA tanking slurry on my cellar wall. Beads of moisture were seeping through. It didn't work very well at all. Moisture was still seeping through the dried slurry. And yes, i did follow instructions on the tin.

[@ultimatehandyman]

Are you sure it is not beads of condensation ? You might be able to test the slurry by getting a piece of polyethene and taping it to the slurry with gaffer tape, so that it is completely sealed against the wall (perhaps a foot squared piece). Then is water appears behind the polythene and the slurry you know the water is getting through the tanking. If the moisture is coming through you best get in touch with the makers.

[@petersalmon4203]

Thanks for that. I have since covered the tanking with Zinsser Watertite paint. In total 5 coats! I will try your suggestion when the drought is over and the water table rises again. My bungalow sits in a hollow and presumably in the water table, so i am reasonably sure that it is due to water pressure from outside.

[@pca8861]

Could of done with a Bigger trowel

[@ultimatehandyman]

I don't always have all my tools with me on every job ;-)

[@Feeney20091]

Hi Mr Ultimate Handyman, I have a Victorian house with original flagstones and ash underneath but it's such an impractical floor as it cannot be covered with tiles or carpet etc. What could I do to make it waterproof and stop moisture rising up through it? Have been told that all my floors have to be dug up, membraned, insulated and then concrete and screed. Does this sound correct or could I just put a slurry like this over it? Thank you :)

[@ultimatehandyman]

I'm not sure to be honest. It sounds like your floors could do with digging up and redoing. I have had a couple of terraced houses and one of those had damp floors, but they were concrete. I simply had asphalt installed over the top of the concrete and the floors are still fine today after 17 years.

[@Feeney20091]

Ultimate Handyman hi, thanks for the speedy reply, it looks as though you've confirmed our worst fears of digging them up! A Polish builder actually suggested putting a water resistant tile adhesive and cheap floor tiles down and then carpeting / laminating over the top of those! Have heard so many ideas that sound a bit crazy but I guess the original floors are so rare now that nobody is 100% sure of a solution. Once again, thank you for your help. Kind regards, Z.

[@johnnyswale5457]

Limecrete. Pricey but will let the floor and lower parts of wall breath. There's a guy on KZbin. Peter ward. He looks at a lot of damp problems on old buildings and how to cure them. He selfs promotes a little but encourages the use of traditional methods to solve damp issues and tells you why damp meter readers are very unreliable

[@usaresident8181]

We have the same issue. I've been told to dig down about a foot and then do a new concrete floor. I've also been talking to a contractor about a product such as RadonSeal which not only seals out moisture, but also radon which is an odorless, colorless gas that causes lung cancer.

[@garvielloken3929]

Nooice!

[@ultimatehandyman]

👍

[@ev3nflow]

creom damp suppressor, by the time you have put your slurry stuff down, id have been at home having a brew watching telly..job done. creom, its the way forwards for you mate..

[@ultimatehandyman]

I just read the instructions for Creom and it said that "Apply CREOM twice allowing the surface to dry between each coat (approximately 1- 4 hours depending on conditions). " So If you had to wait 4 hours between coats I would have been home before you ;-) Seriously though I'll check that out the next time I do something like this ;-)

[@ev3nflow]

well get the kettle on if your home first..:) its a good product for sure. we use a few products F ball and co, do one and two part isolators and high performance ones too.. creom is good for fractures and cracks before and after repairs then again before a screed, it goes of pretty quick on most concrete floors to be fair.. half the time its down to cost, but for us, because we do a lot of lvt, it has to be right..just to bloody cover your back down the line, so you can walk away and know its not gonna blow the screed .. flooring would be dead easy if weren't for customers ..lol

[@ultimatehandyman]

ev3nflow Thanks for the info ;-)

[@TheWezzo124]

I've just been reading about creom and it appears it shouldn't be used on slabs with no dpm for the installation of LVTs, wood etc if the RH is above 90%. I'd still be a little twitchy if the RH was lower that 90% on slabs with no dpm as such values (RH) can change through the seasons. The cost of creom is also high. I think for the cost and use in such instances, tanking slurry has the edge. Thoughts??

[@ev3nflow]

Fitmywoodfloor yes mate you may be right, with regards to creom. its a suppressor rather than a inhibitor.. i recently was om the quickstep master installer course for lvt (i passed) lol.and darren there showed us a ardex product that is a 2 part one coat deal that was brilliant.. he mixed it up and poured it into a plastic beaker of water..it basically displaced the water..just pushed it out.. very impressive really.. but bottom line is cost..im sure its not cheap, like creom, but it would do the job.. we had a job not too long ago, a big lvt (karndean island lime stone) in a big kit/diner in hale barns where a lot of city and that other team local, i think called united live.. affluent area..and it was a new build, we waited 6 months and still had damp readings..we ended up getting the client to asphalt the area and then screeded it with ardex na.. the bitumastic floor kills the damp and then we could go from there.. its a nightmare, the margins with lvt, with the pressure and stress it can bring are not worth the effort half the time.. check the ardex products..they are good..

[@jimsmith5184]

Thought the concrete had to be wet first?

[@ultimatehandyman]

Can't remember now, I've since thrown the container with the instructions on! Thanks for the comment

[@rrichyl9401]

Had a similar situation in my house, but opted for mastic asphalt in the end..

[@steverichens4242]

I can’t understand most of what you’re trying to tell us

[@daddyxtc]

It's a concrete floor btw.

[@t.garratt5371]

Hi, Nice video.From KA's site I see you can use this on garage floors. Would you need a 'finish' of some type, such as a garage floor paint etc?TG

[@ultimatehandyman]

+T. Garratt I would imagine so, but it's best to drop KA a quick message to check for compatibility etc.

[@KB-ki7um]

Damp metre?

[@ultimatehandyman]

Meter

[@joshenglsh9491]

No SBR applied what a cowboy lol

[@ultimatehandyman]

I applied it exactly as recommended by the manufacturers ;-) Thanks for the comment

[@dinosaurconsumer2481]

The moisture will just rise up the walls and cause rising damp in the home above, as it tries to escape around the edge of the floor where the tanking ends. Thanks.

[@ultimatehandyman]

The walls have a damp proof course installed (DPC) Thanks for the comment