Installing External Wall Insulation - Is it a DIY Job?

[Music] now you don't need me to tell you that this is a pretty ropey old wall so what we're going to do with this wall rather than rendering it or trying to repair the brickwork we're going to put some external wall insulation over it one for a Cosmetics just to tidy the whole thing up but the other thing is it will dramatically improve the insulation in the building so it's a win-win as far as that goes but before we do that there's the issue of damping the wall now it doesn't look too bad here it's got a reasonable overhang but just as a precaution we're going to put some dry rods in all the way along to stop any possibility of rising damp because the last thing we want is for that damp to be creeping up behind the external wall insulation the external wall insulation is breathable it's not a closed cell structure it's an open structure the moisture that's in the wall will evaporate out of a wall but we don't want to be constantly feeding it with new moisture we know that it's a nine inch wall 225 millimeters so so we're going to set this drill so that we're just short of that by a 25 mil so we don't come through the other side and then I'm just going to drill holes along the perps so one there one there one there and I'll just go all the way along put the rods in and what they do is there's a saloxone inside the rods which leeches out it's attracted by the moisture so there's any moisture in the wall it leeches out and it lines the pores inside the mortar itself so we're not trying to drill The Brick we're not trying to form a barrier across the bricks we're forming a barrier along the mortar line [Music] thank you I've primed this bit of aircrete block with some dilute SBR the rest of it when I run my hand over the brickwork I'm not picking up any dust I'm not picking up anything from it so that's fine we can stick directly onto that but just remember you can't stick to dust so if in doubt Prime now any ewi store they sell a repairing mortar which goes off in about 10 minutes super sticky stuff so if you've got something like this and you need to dub out you need to fill in all those holes then that's the product to use because 10 minutes later you can be put in the adhesive off you can see here where the rain water pipe has leaked and it's run down eating all the mortar away but it's left this green mold we need to get rid of that because the last thing you want to do is leave that there and it starts to activate and creep up behind the insulation so just give it a good anti-fungicidal wash scrub all the green mold off and then you're ready to go [Music] so this is the second part of a starter truck it's the same length as the starter tray but don't make the mistake of using it as it is straddle the join because if you do that you're joining the two pieces together and that will mean that you'll get a nice straight line and you can put your rest of your fix into now they do make aluminum trays as well as plastic ones you might think that if you're using plastic there's no chance of you cutting yourself but if you run your fingers down the edge of that that is sharp believe me so to start the track is actually fixed back against the wall but it's kind of a little bit Meandering but you don't worry at this stage so long as it's fixed back what I'm going to do is put the insulation in place and then I'm going to prop it underneath get the spirit level and make sure it's all right then when the adhesive is set that will be absolutely level in line [Music] so this is the adhesive that we're using for this we don't have to worry about cleaning that bucket out too much when it comes to the top coat we definitely want to be clean think of the top coat as plaster when it comes to mixing adhesive most people are just open the bag Chuck it into the water and whisk it up if you read the instructions which nobody ever does tells you how much water to use for per bag so measure it out then whisk it up and then it says leave it for 10 minutes so there's your cup of tea time because if you don't leave it for 10 minutes it stiffens up you go to use it you've got no movement you let those polymers over that 10 minutes soak into the water and then the whole thing needs to be re-wisked just give it another spin through and then after that you've got about two hours to use it and it's a lot more pliable honestly so many people make this mistake Chuck it into the water whisk it up and go because they're in a rush have that cup of tea now another common mistake that people make is that they look at the mix they think okay that's all right and then 10 minutes later they come back and they think oh I'll add a bit more powder a bit more water it's not quite right and if you do that after you've let it have that 10 minutes it's a terrible thing to do the adhesive will not work as it's supposed to this is the highly engineered stuff but if you need to add powder or water to it to get it right do that before that 10 minutes of settling time if you like then you'll be okay but after that 10 minutes of settling time don't try messing with it foreign [Music] adhesive the important thing is you've got to get the perimeter covered it also needs something in the middle because you're going to be putting these fixings through the board and you don't want to be putting them where there's an air pocket behind you wouldn't be putting them where this adhesive so that way you're supporting it on the fixing so if you did it in three lines absolutely fine but this way we know that we're one in the middle one either side you can see I really got quite a thick bed here but that's because this wall is all over the place if I was doing it on something like render carrier ball all I'd have to do because it's nice and flat nice and straight it's just using a notch trowel through to do it obviously you've got to adjust it now another thing that some people get wrong is that when they come to a window here because it's easy because I think oh I'm just going to put a sheet there and up there and I think okay we've got a bit of a bond there but it's not really good enough what you need is to half Bond it and then do your L shape because if you do an L shape you haven't got that straight line which will crack later so very very important that you keep that Bond all the way through and that you avoid straight lines like the plugs exactly the same as plasterboarding or anything else [Music] now I made a little bit of a Schoolboy error because I should have actually taken that flush with the top of the seal because when we come to put the cover on the cover needs to sit on top of the existing seal and slightly down so that it runs off but you can see what I've done here I've cut it below rather than on that line it's not the end of the world because it's very forgiving I can get a bit of adhesive a little bit of an off cut and pack that up but on the next one I'm going to get it right [Music] I'm amazed at how much open time you get with this adhesive I mean it's an hour and a half now since I mixed it up and it's still pretty workable now obviously that's going to change in the hot weather it's going to go faster but it's pretty good there might be people who are looking at this saying why are you bothering with that adhesive if you've got a flat wall why don't you just mechanically fix it just drill it plug it if you do that there is a tendency for the boards to move it might not happen straight away it might be six months might be a year down the line but at some point they will move and you will see cracks so although the adhesive is a bit more expensive obviously it adds a stage to it don't try and skimp on it because that's the difference between a job which will last and having callbacks [Music] this rasping is essential for a number of reasons one is that you can see there's a few lifts on the boards where I haven't quite got it flush so this will give us a nice flush board which will save us on adhesive because the flatter we get this the flatter we can get that base coat going on we only want to put that base coat on and say what four mil something like that six mil maybe no more than that so getting this flat is essential but also these are made of oil these bolts okay so in the hot weather they will sweat slightly you'll get a kind of a shiny film on the board and the adhesive doesn't stick brilliantly to the shiny film so if we get rid of it we just knock that back get rid of the shine on the board the adhesive has a much better chance of sticking foreign [Music] at the top here we've got the EPS joining some OSB so that's two different materials and whenever you get two different materials you get differential movement you get expansion and contraction of one or the other so what we've got here is an expanding foam tape we've put that into the Gap and it miraculously expands over an hour or two and that fills that Gap and of course if there's any movement there it will go on there so we're going to cover that anyway this is really good practice saves any water leaking down behind the EPS it saves those cracks now I've got to admit that because this is my first go at this at this stage I would think all right let's get the mechanical fixings in let's get that Drilling and that plugging done but the guys at ewi store giving me a few pointers here that's a good thing they're not just selling you the kit they will give you advice and what they said to me is don't do that get all your beads set up get those stuck with the adhesive because while at setting you can be doing all your Drilling and fixing if you do it the other way around you've done all your Drilling fixing then you've got to do your beads then you've got to wait for the adhesive to dry now comes to the time when I'm going to fix the mesh but I didn't do this before I did the raspin because if you do all those little granules get into here and that means you've got to vacuum the whole lot out you've got to get rid of those because you don't want those going into your base coat so rasp first clean up then put your angle beats and all the rest of it your trims up something else I've just learned that I never ever knew this I've used this mesh quite a lot in the past but I didn't realize that it will absorb water the same goes for the trims all this mesh is a kind of it's not exactly plastic as we know it is it's a water-based product it's absorbing water so you must keep it in the dryer and what I've had in the past I've had problems I've put a piece of mesh on the whole thing's dropped down you know because it's too heavy and that's because I've left it out in the rain it's absorbed water it's twice the way it was and then you have trouble sticking it so keep it dry guys that's all [Music] foreign [Music] thing here is let's keep these overlaps on the mesh everywhere because if you do that it saves any chance of cracking [Music] foreign [Music] you've got to watch out for the depth you don't want to go any deeper than this really just this plus a little bit say 10 mil so that bit of tape on the drill is absolutely fine it's just worth checking what wall you're drilling into measure your wall try and avoid any cables if you think there are cables in the wall very simple thing you can do with Ferrar areas where you don't want to drill because of cables or something else just mark it up when you put the adhesive up if there's something behind there then at least that tells you not to drill there foreign so you can see that the pin that goes through the middle is grp which obviously means that it's not going to transmit the coal as much as something like a steel a stainless steel one but there's more to do because you really got to put this insulated cap over the top because if you don't there will be a transfer of coal through to the inner skin and you'll see all these little dots appear on the inside wall with that bit of thermal Bridges so as thin as this is it's doing a very important job bit like me now that is a stress patch and the whole idea is anywhere on these Corners around Windows Doors any other opening there is a tendency for it to want to crack up there it just happens if you don't believe it look the comet aircraft it happened with those until they made the windows around so you just have to make sure that you reinforce it we're still going to put mesh over the top of it but this is the first bit foreign [Music] foreign foreign [Music] so that's the base coat done all we've got to do is leave that for 24 hours to dry before we put the primer on and then another 24 hours after that before we can put the top coat on now you could skip the primer quite honestly on this surface it would be fine but the reason we're using the primer is because we've got a color change between the base coat and the dark top coat and to stop anything showing through on the base coat we're using a pigmented primer which is the same color as the top coat so it gives us a fighting chance if you like if there's any tiny little bits where the grain has missed it's covered now there will be people watching this who are wondering about the fire risk with putting this kind of insulation on the outside of a building well this has been tested and it's rated the class B rating which means that it won't contribute to the spread of flame importantly you don't get burning droplets so those situations where you've got cladding on the outside of a building and the burning droplets are spreading the fire down downwards as well as the fire running upwards that will not happen with this insulation all right Rogers asked me to apply this ewi top coat primer to the surface that you've been working on I've given it a good stir that's quite important to mix all the chemicals together [Music] right so we've got the primer done and it's important to leave it 24 hours before we put the top coat on so Roger's coming in tomorrow weather permitting to get the uh the top coat skimmed in okay so the prime has had time to dry now we're going to put the top coat on which is a one millimeter silicon so it's a little bit unforgiving got to do it right and uh we've only just got about enough material to do the job so I can't afford to drop any on the floor if I drop it on the floor I can't scoop it up again because then you make a real mess now I'm quite happy doing this but AWI Pro have offered me the services of Paul who is actually their training guy at the Aylesbury Academy they've got their own training facility at Aylesbury and Paul runs one day courses there so what tips are going to give me Paul basically this is the one mil aggregate in the Silicon window so it needs to go on at one mil thick yeah so we put it on just as you would Plastering we apply it and then we scrape it back to the thickness of the stones that are in it which in this case is one mil got it and then we can try and texture it put it on take it off when you say texture it it takes it with a plastic float it's not actually a texture in terms of yeah all you're trying to do with this is basically roll the stones around to get rid of any Trail lines okay you basically just throwing a little holes and it moves the stones around gets rid of any trowel lines and evens it out of thickness so what have we did we put it all on first and then rub it up or do we go as we go I do it as a go some people will put the whole wall on yeah all depends on your drying times on the weather and what it's like on the day foreign oh it won't go any further than that okay as a beginner I'll drop back and try and start to texture this because the joints you leave are where it's going to dry and as it dries if you try and rub it it drags the stones apart and it will leave scars but so we can't have a day joint basically we must get a whole thing I need to get the whole wall I mean experience guys would probably put this whole wall on before they start to uh yeah to texture it but in our case I think we should drop back start to texture it and then we'll move on to the yeah Okay and like you say it's the weather is everything isn't it I guess it's not just Sun if it's windy as well it's an air dryer material oh okay so as soon as it's out the tavern on the wall it wants to dry and this is a bit I've never done this plastic floating yeah plastic floats for plastic Trails I think what you could want to call them we call them plastic float yeah um it's basically just place it float you go rub around your circles we're just trying to roll the stones around to take any Trail marks out anything like that the important part is to keep it clean oh okay scraping it off on there got it don't wash it with water if you wash it with water and put it on the wall you'll get water marks because it's a water soluble silicon yeah so uh that's how we do it now the reason I call this a float is because it's not like a plastic you know look like the flex nut trails and the reason I like soft edges yeah the reason I don't call it a float is because traditional sand cement plaster is yeah it's a big thick polymer urethane fly yeah okay season right so we couldn't use it before you a phone float right so it's a trail but it's a flat Trail and and they sell these yeah yeah they sell all the products all right okay mate do you want to show us how to do it yeah once the materials on the wall we need to scrape it back to the thickness of the stones yeah which is a lot thinner than people think it's a one mil stain so break it back you can see how much comes off slimy wow if we scrape it back to the credit it's a hard scrape isn't it yeah if you scrape back to the correct thickness straight away it will float up nicely it's almost done isn't it yeah basically all you're doing with this is just rolling the stands yeah to take out any Trail marks any marks any little holes yeah all right and it's important to keep scraping that off you're doing it on your own you need to finish as you go it will dry [Music] it's got to be stainless steel yeah okay how about you get black black marks foreign I'm scraping it off but I've noticed you're scraping it off again after me what would happen if we started floating up with a plastic float on this thickness it's a very good point I can show you um it basically it will go fluffy and start to drag okay fluffiness it's almost like pricking it up isn't it yeah yeah and it sticks to your trailer a lot more got it that's why we get back to the as I say if you scrape it back to the thickness of the Stone straight away it will rub up really easy [Applause] what about trying time in general 15-20 minutes before you need to rub it up yeah but what about rain-offs you know rain yep about five to six hours oh okay and it can probably take rain yeah so it really does depend on the weather yeah yeah um in the winter obviously you've got to watch your overnight temperatures yeah because if the temperatures are dropping below five degrees overnight it won't set it foreign [Applause] so that's it that's the finished coat on and I've got to say it's exceeded my expectations which is always a good thing isn't it it actually to my mind looks more like a traditional sand and cement finish because it's that one millimeter grain and uh I think it looks fantastic it's a self-cleaning surface as well as it rains being silicon it will just wash off which is beautiful you don't get that same staining that you get with some other Coatings so what we're going to do is remove this now we've got these special beads on here so I'm not quite sure how this is going to work out could leave it till the reveals are totally dry so a few hours six hours come back but we're going to try it and the great thing is that with the reveals you can patch them up if we pull a bit away we'll just go around with a trail and Patch it up so let's give it a go yeah how do we do it just just take it away and then obviously mine just be careful because the Wall's still wet so we've now taken this off but the bit I'm not sure about is how you take this off how's that done the easiest way I find to take this off is if you pull it towards you it snaps all right okay if you pull that that way it'll snap oh okay yeah like this oh I see fold it back all right okay I thought you meant just now and then if you get the top and peel it straight down it's not too bad because we got that little bead on there which is the same color as a window there's no need to do any silicon in no they do need a little tidy up little brush or something just brush them in because the reveals are wet I can pick some of it so you just you can just run a brush down there and we'll tidy that up all right but all right so so I matched these beads to the windows because otherwise if you match it to the kind of the render it looks like the renders come round onto the frame so that's it that's the external wall insulation system from ewi Pro now this is only a small wall obviously I was only trying it out for the first time but you can see you can scale this up you've got the techniques there whether you're going around a window or a doorway or anything else same thing applies so it's just a question of following the instructions don't try and Skip bits don't try and be clever and then you won't come unstuck I'm Roger but if you come back to see us soon on school board we're going to be doing more of this stuff [Music]

Channel: Skill Builder

Views: 665,666

Keywords: external wall insulation, how to install external wall insulation, insulation, wall insulation, wall insulation installation, solid wall insulation, how to, external wall insulation rendering, external wall insulation fixings, external wall insulation plugs, external wall insulation on cavity walls, external wall insulation kits, external wall insulation diy, external wall insulation uk, ewi pro silicone render

Id: 96WN8AtAvNg

Length: 26min 3sec (1563 seconds)

Published: Fri Nov 18 2022