Self-levelling a floor - The Complete Guide

I'm Alex Moore and this is a super detailed guide to leveling a floor using self leveling compound [Music] [Applause] well straw in a few hints and tips and here's our first tip buckets these black buckets you find them everywhere and on the inside there's a scale that shows you your number of litres or gallons and it's pretty hard to read because it's black and he's just kind of slightly embossed on the surface of the bucket so what I do whenever I buy these buckets I grab a paintbrush and some white gloss and just run a bead of white gloss paint up the scale and that means that then when you look at that scale it's really easy to read in any lighting conditions at all I found myself you know in a normal one of these buckets you're in there with your mobile phone with the torch trying to find how many litres have I got in there oh the phone's in the bucket it's inevitably going to happen to me that makes life a lot easier with these buckets let's level this floor we've got a 42 square metre workshop here with a concrete floor which has just been poured now there's two problems or by the way 42 square meters is 420 square feet for our American friends so this is a good sized room to level in this is fairly big job if you would DIY leveling so this floor has a couple of problems with it with this concrete one is is it's very very dusty and what you find is when you've got concrete which has been laid with a little bit too much water the water rises to the surface and it brings up the cement with it and then you end up with a surface coating of water and the water evaporates leaving a kind of dusty powder on the surface and you can see that probably more visibly here and it's got a name escapes me now give me a second I'll think of it later [Applause] so latency is what it is and it's this powdery substance which nothing really adheres to but basically you want to scrape it off or sweep it up because with a bare concrete floor like this and you don't seal it you'll always have dust rising off this floor and I think people will have experience of never-ending sweeping on a concrete floor and you sweep it sweep it the dust still comes up you sweep it some more and there's more dust so that's what we're trying to solve here obviously the other problem is the floor is not completely even we've got dips and valleys and things across here around five millimetres deep in places so we poured a self-leveling compound and it's gonna do two things for us is firstly it's going to level this floor and give it a nice finish sec it's going to deal with the dust situation and basically it's gonna seal this floor self levelling compound is relatively cheap and in fact I find that it's not much more expensive to just self level a floor rather than by concrete ceiling do a few coats of that because self levelling compound gives you that level floor and it's also hard aware and then it's gonna last longer let's get started hi there I'm leveling a floor so the first thing you want to do with your floor is just get a straight edge and just run that around the floor checking at various points to see where's the high spots where our low spots and what's the difference between those now if you've just got in one area of the floor say for example you've got a hump that's five millimeters high well it might be best to do is to grind that hump down or if you've got small high spots for example just chips them off with a chisel because you're gonna have to level the floor to the highest point on that floor so if there's just one area that's say for example ten millimeters deep you have to pour ten millimeters of self levelling compound across the entire floor to get up to the level of that high point so if you break that down then you're obviously gonna save yourself a lot of compound once you've assessed the floor and you've worked out what depth of self level and you're gonna pour you can then go and calculate how much you need how many bags of the stuff you're actually going to need to buy it is different types of this stuff but every bag will tell you how many kilograms or pounds of compound is needed per millimeter per square meter I have no idea what you would use in the US but in Europe is per meter squared and per millimeter of depth so for example this room's 42 square meters and we want to pour around 8 millimeters deep on average across the room these this bag tells us that 1.6 kilograms of this powder will fill 1 millimeter deep 1 meter square so if you take a 1 meter square area you put 1.6 kilograms of powder in with some water that will create you one millimeter deep so if we want 8 millimeters deep or let's say 10 millimeters deep for easy maths 10 millimeters deep across one square meter is going to need 16 kilos of powder these bags generally come in 25 kilo sacks so you can work out how many sacks you need per square meter so self leveling compound itself is a mix of cements and a very fine kind of aggregate a sharp silica sand or something like that along with some various additives to make it flow more easily something like latex as well to prevent it from cracking there's all different blends of the stuff you'll find that for different purposes there's different stuff so I'm sure when you go down the store there'll be ten or fifteen different types of this stuff basically a normal stuff is going to go about two millimeters deep to ten millimeters deep that's a typical turn of your bog-standard traditional self leveling compound and then from there you'll find that there's ones that go to create much deeper so up to two inches fifty millimeters deep you'll find it's kind of a thicker mix for a deeper pour you'll also find faster setting stuff so this is dry to foot traffic in 24 hours you can find very commonly stuff that's drier to foot traffic in for hours and even for commercial projects where people really want to get in and out as fast as possible stuff that's dry within an hour and you can tile straight onto it and when you see this stuff come out it's liquid it's amazing that you can pour it and an hour later you can tile straight onto it walk on it this stuff you know very normal stuff are the ones that you'll find a lightweight mix that you can use in attics for example if you're doing a loft conversion something like that in a property and you're not sure that the Timbers the existing building structure can bear the weight of a for example a 50 millimeter pour then you can use a lighter weight self levelling compound which weighs about half as much for around 16 square metres of room you're gonna find that the traditional self leveling compound is gonna weigh around 2,000 kilos if you use a light weight stuff that's probably down to a thousand kilos something like that you also find out it's stuff with higher compressive strength so that's for something like a garage where you're gonna have heavy traffic you know heavy load on that floor you want harder compound so you'll find all these different varieties and then you'll find obviously sub varieties in that hard and fast setting now the thing with setting time is unless you need it to be setting quickly unless you need to be tiling on it the same day then I would suggest grab stuff that doesn't set that quick because you've got a little bit more workability to it there one other thing while I remember you've got to pay attention this stuff's really easy to work with these kind of it proof but if you don't follow the instructions you can't just freestyle it you need to stick to the instructions that means if it says it's for between two and ten millimeters and don't pour it 20 millimeters thick because it's not gonna work at that thickness likewise if you buy the stuff that's needs to be between say four millimeters and 40 millimeters and you spread it really thin down to one millimeter it's not going to self level because is the depth that is designed to self level at so the stuff that's for one to ten millimeters is more runny the stuff that's for four to forty millimeters is less running it's more viscous and so you make it thinner it won't run it won't self level the other thing that you really need to pay attention to is the amount of water that you mix this stuff with but we'll come to that later bear in mind this is not something like plastering or concreting mixing mortar where you can just eyeball it have a feel of it oh it feels good let's go you've got to follow the instructions on the bags the other thing is use the right primer you know if you can find a primer that matches the product that you're using go for it even if there's a known brand primer on the Shelf that's a bit cheaper it's worth sticking with the products that you know we're going to be compatible with each other because the number one thing is if this floor doesn't go down right for example it cracks or it doesn't adhere correctly to the subfloor then we're gonna have to chip the whole thing up put it in bags throw it in a skip outside and do the whole thing again so if there's something that's worth doing once and doing right it's letting self-leveling in fact it's laying any sort of flooring substrate or any flooring at all really but you know the lower you are in the build the more you're gonna have to demolish to correct things if you make a mistake so basically this stuff is idiot proof just follow the instructions okay how does that look so first step is brushing the floor with a brush but this brush is useless it's only good for witches you want a stiff brush stiff bristles like this gets stuck in you're not tickling it you really want to lift all the loose stuff off because no matter what you stick down on the air even if you were to get super glue and you were to stick something to the floor with superglue here if what you've stuck that superglue to is just dust and it's not actually fixed to the floor it's just dust this is gonna fall off it doesn't matter how strong the chemical that you're using is if what you've adhered it to is dust or loose material it's useless you have to get the dust off these floors get stuck in with a stiff bristle brush once you've got most of the loose material off coming with a Hoover if you can you know don't use the fine quality Miele Hoover from the house so you'd be in deep trouble but you know maybe maybe do it anyway we've got plastic fibers in this floor which hold the concrete together and give it much stronger you would do that because we didn't want to put mesh in the floor here so you can make things easier when they mix the concrete not the factory they add this these fibers to it and they bond bond of stuff together and prevents it cracking it makes it much stronger because this is around 50 mil thick this screed here now I know that these will stick up through the self levelling compound they almost float up to be vertical as you look at them here you know you wouldn't believe that I'm a stick up by know that once we've poured this we're gonna have like a kind of a little grass effect every few centimeters there's going to be a little piece of fiber sticking up but that's just the way it is we'll go around with some nail clippers and trim them off or the lawnmower the other thing you need to do preparation is you need to block off any drains or anything like that the openings in the floor so we've got one here you know we don't want to fill that with self levelling compound so polystyrene is always good you could cut this out of a piece of wood or something similar and just make sure that it sticks up proud of where you're self levelling compound is going to come to because otherwise you'll go over the top of it and then you'll struggle to find it and have to chip it all away once you've prepped the floor the next step is priming so you're going to want to grab some primer now don't skip the primer step absolutely vital may be the most important step well they're all important steps but this is a very important step so you'll find different types of primer sometimes any diluting three-two-one with water this stuff you just pour it straight in and you'll find these primers the good primers anyway they have a color this one's pink you find green or blue the reason they've got a color in them is that when you paint it on the floor you can see where you've already primed easiest thing for me I just sip the whole thing in here nice big bucket tip it in there grab a roller and just roller it straight out of the bucket all over the floor alright now I think we'll get through at least two of these we've got that stuff out now treat yourself to a long handle for your roller if you just use the actual roller you know and you're crouched down and you're rolling like this it's not fun it's exhausting so a long handle is going to make this much much faster and also easier on your back you can make it even easier you just sip some out on the floor just slop some around and then we'll spread it out with the roller why are you priming in the first place well there's two reasons why you're priming you know everyone knows that you're primed to make something stick more easily to the surface below but the actual main reason that you're priming or the more important function of the primer is to slow down the absorption of the water in the mix that you're going to make what you don't want to happen is a very dry floor like this to suck the water out of the mix and that leaves no water for the chemical reaction what's happening here with this stuff and with a lot of chemicals concrete is a similar situation it's not drying out you know we say oh we're going to leave the the self levelling compound to dry you know as though we're talking about the washing or something that's not what's happening here it doesn't dry the water doesn't evaporate and disappears the water that we add so we take a sack of that we had five liters of water we pour that onto the floor those five liters that we added combined chemically with the compound in the bags to create the hard surface it doesn't evaporate so we don't want it to disappear because if two liters of our 5 litres get sucked into this floor then the mix is no longer right and the the actual substance that we've laid won't be that strong it applies to plaster on the walls equally so the reason we're sticking down a primer is almost like a varnish it slows the absorption of the water from the self levelling compound that we're about to pour onto this into the subsurface the amount of primer that you're going to use would depend on how absorbent the floor is if we were pouring this onto an already sealed floor for example we don't need to use too much primer we need to worry too much about it but when it's very very absorbent like this obviously we need to make sure this is Prime nicely anyway enough science [Music] so we're almost finished priming the floor here I'm just going to work my way out of the door so don't box myself into a corner the primer takes check the pack but this takes around an hour an hour and 20 minutes to dry and it wants to be dried don't pour the compound onto a wet primer because what happened is that wet primer will rise up through the liquid and it will kind of form a surface and leave like a chalky colored deposit on the top which is not what you want certainly we're not what we want because this is going to be our finished floor in here for my money self leveling compound is actually the cheapest way to make a finished floor it's cheaper than tiles it's cheaper than laminate it's also a precursor to laminate and tile so if you're going to tile or laylamon at flooring you need to self level the floor anyway so what I'm going to do here is we're going to pour this this floor and that's going to be our finished floor for a while and then later maybe we'll place some tiles maybe put some real wood down maybe we'll just epoxy the floor but in any of those cases you need to put the self levelling compound first and if you do a self leveling right it's actually a nice finish it's a smooth floor it's dust free you can sweep it easily I'm not going to say you could eat your dinner off it but I would happily eat my dinner off it so self leveling floor it's not just cheap in financial terms I would say this is probably going to cost around five dollars a square meter or something primer everything all-inclusive cost it's cheap in financial terms but it's also cheap in time because we can lay this whole floor in a day no problems probably half a day really and it's cheap in terms of skill yes there's a lot of derogative to anybody you know if you're laying tiles for example it requires skill and if you're not an expert at it you're gonna work slowly to do it if you're gonna get a nice finish likewise with laminate flooring you know it takes concentration and labor and really you know self leveling stuff you prime the floor you mix it up you pour it in it finds its own level as long as you kind of you know have some organization to it it's easy it's also cheap in terms of tools you don't need much to do it you know the only real specialists all you need is a puddle mixer and you can even just use a paddle for a drill guess the reason I recommend it I mean I don't recommend this for your living room but if you've got a space that's kind of industrial shared shop garage something like that this is really an effortless floor to put down his cheap I've seen guys painting using concrete floor paint which is relatively expensive painting straight onto concrete and guess what you know it doesn't stick very well it wears away after a year and it looks awful and the floor still uneven in the end anyway self leveling stuff is kind of a miracle substance the floors we're ready to start mixing the primers dried we're gonna mix up our first batch what I would suggest is you mix full back at the time don't attempt to mix a half bag the maths is easy the measuring is easy take a full bag at a time that's the way to go a full bag of this takes five and a half liters of water so we want to measure up five and a half liters and we want it exact we want to be well within 10% ideally within two or three percent so we don't want five liters we don't want six litres we want exactly five and a half liters what I have here is a bucket now I don't know how much I trust this bucket I've just used it to mix plaster and things and for that sort of thing you're kind of mixing it by feel I'm going to use this kitchen jug to measure out five and a half liters into here and see how accurate it is that's one liter that's two laces let that settle imma stick this back in the house before I kick it over and then we'll come back and scribe a line for exactly five and a half liters so this is settled now and we can see the level we've put a level on here to make sure the book is straight exactly five and a half litres have gone in but the actual level of the water is on the five litre mark exactly so this book is 10 percent inaccurate which is no surprise really first time you buy a bucket like this just you know calibrate your bucket it sounds crazy but it's worth the effort so we know we want to be on the 5 mark for 5 and a half liters we have our water measured out so we're ready to start mixing here's our mixing station it's kind of well set up it's organized it's good to be organized when you're mixing because you want to be productive you want to be slamming a bag in there mixing it up taking it inside pouring it getting back and getting another one done because we've got 22 bags to get through here that's a fair old number our water supply is coming through a hose which is the easiest way to do this if can't use a hose for some reason then you're gonna have a couple of buckets of clean water then you have another bucket which you're using to measure out your mix which is for us five and a half liters of water then we have a big bucket for mixing in because we're gonna take a whole bag of this 25 kilos without five litres of water into there so when this is finished this is gonna weigh 30 kilos exactly so you need a good bucket it needs to be clean these flexi tubs a great for it because once you've finished you can you know clean them up nice and easily that means to be honest you're gonna clean it anyway but for concreting and things they're good because you can knock the sides and get the mix off unfortunately the handles broken on this one so it's not good for carrying I've got some other ones but they've got a ribbed on the interior which is not for my pleasure because the mix sticks to the inside which is not ideal but we'll give them a we'll see how it goes now with our big bucket we've also got a trowel here the reason for that is as we're mixing the mix that the powder will tend to stick to the sides we want to just get in there and scraped off and let it drop so a big bucket and a trowel for cleaning up and scraping down to the bottom then we have another bucket here and this is for cleaning up so you've got to keep your tools clean as you're doing any sort of work with mud anything like that plaster whatever you've really got to stay cleaner so I have a brush in here I love this brush just exactly the right stiffness always helps the right size everything about it brilliant just a bit of clean water in the bottom there and we can stand our mixer in here whenever between mixes you don't want it sitting on the floor getting dirty whatever that is our mixing station let's get cracking now I completely forgot to talk about the mixer which is probably the most important thing here you really need a paddle mixer for this job particularly if you were taking on this many bags if you're mixing up two bags you can use a drill and a paddle no problem you'd be alright with that but for more than that you really really want a paddle mixer because you get two hands on there and when you're looking for one this one is brilliant because look at the height here as I'm working this mixer at the bottom of the pan I'm not having to bend over now I've had previous mixers where it's a lot lower than this and so you'll like this that's no good if you're mixing for an hour two hours out here you really want that height so you can keep your back straight and just work this around this is the right paddle for mixing self levelling compound you see that the bars are straight here and a normal mixing paddle for pain to plus or whatever they usually got a spiral shape these bars being straight means that air is not being forced in or out of the mix it's just circulating around breaking up the powder and mixing it well you can use the other the other paddles it's gonna work for you but if you're by omeone specially get the right paddle and that's this one five and a half liters of clean water in the bucket water in first always get back rip that open sit back in there lovely get a mixer give it a quick up-and-down [Applause] but as you're mixing you want to get up and down yeah once you've got a decent mix in there get up and down and just work the power which will settle to the bottom back up to the top get in the corners now once you almost finished just take a trowel and just work around the edge of the bucket there and just have a feel around the bottom to make sure you've not missed any huge lumps I've got this down there this has got a nice creamy consistency I mean it's very very liquid you're not plastering this stuff on you're literally pouring it that's ready to go give that a quick spin in there watch your hands on these mixers they're actually a very dangerous tool if you if you were to spin this with your hand in there or get your hand caught in that it's going to do you an absolutely horrific injury at least as bad as a circular saw or anything like that is really any sort of mix I like this the force in that blade it's just going to mangle your hand up so just be aware that you know it looks pretty tame but it's actually quite dangerous too I've got here a sack trolley just to save some exertion and I can just wheel this mix down to where I want to pour it because it's about 15 meters and I'm gonna carry it much easier so I'm just gonna grab this just tip this out just slightly away from the wall we let that out empty the whole thing oh you're using your trowel for is just to move this stuff around you're not attempting to smooth it in any way you're just trying to place it that's all you're doing you're just moving it to you know encourage it to flow a little bit because this bag let me think should be ten kilos per square meter so this bag of mix should be covering around two square meters so we want to encourage this to flow a little bit more to get this out over two square meters and then we know that we've got our eight millimeters thickness that's kind of the easy way to estimate this you know it's not a precise art look how easily that flows we've got a little lump there it's gonna mix another five liters of water and we get in the flow now work our way through the next 21 bags one more bag what is important with this is that you work into a wet edge at all times you can't allow this to dry go and get your lunch and then come back and pour the next lot you need to pour you know one continuous pour almost working your way you know along keeping it joining into two wet self levelling compound so you should pour bucket after bucket until you're done is there enough for the corner so where you've got two that have met you just get the trowel on there and just blend them into one or we want to really blow that back there cover all this on this horrific bumps [Music] so as you lay each layer each bucketful you want to spread it into the previous layer and just run it around that's all you're looking to do ideally get the levels of them nice and even and then there's a tool I didn't mention earlier which actually is really useful if you're if you're doing multiple buckets like we are 23 buckets of it then this it's gonna blend the layers into each other or blend the pours into each other so what you do once you've spread this around and that's you know that's quite a thick pour you get a feel for how deep is at the edges you really want to push it and flow it towards the edges and then it will flow back into the center of the room and you can see we've got little raised area where this joins into the previous pour so we take this spiked plastic brush and just roll it nice and quickly each time we do a pour we just roller it over the whole thing but mainly we're aiming for this join and you can see what happens is it just kind of blurs that that join it forces it to flow into every one of these spikes people think this is for removing air and I'm sure it helps with that but what it's really good for is just encouraging that little flow here we are 24 hours later the floors dried he's got this lovely finish on it almost a rubberized coating which it's gonna be great to work on this is gonna be dust free easy to keep clean now it's unusual that you would leave this as a finished floor certainly in a home or somewhere like that be very unusual to leave this but for us for our purposes this is absolutely great there's a couple of things which for a finished floor I would have done differently one of those things is that there are places where we have some raised dots and that's because I roll it this slightly late and the mix had thickened up and once I rolled it with despite roller those dots kind of stayed raised now if you were tiling on here or laying a finished floor on top of here absolutely no problem with that in fact you know it may even have better adhesion for your adhesive or whatever like that but for our purposes we kind of got this dotted finish no problem it's great I'm delighted

Channel: Learn Building

Views: 805,933

Rating: 4.6338611 out of 5

Keywords: concrete, self-levelling, latex, floor compound, smooth floor, tiling, mixer, self-level floors, uneven floors, concrete finishing

Id: vc_5eAKILiY

Length: 26min 26sec (1586 seconds)

Published: Sat Jul 28 2018