Hemp Concrete Walls (R30 + Fireproof) - You Won't Believe How They Built This House!

guys this building behind me is absolutely beautiful but what we're here to talk about today is this crazy wall section it's like fluffy marijuana concrete it's actually called hemp crete and you're going to see the entire process guys from mixing it to forming it to pouring on today's episode this is really going to be a fun one today's build show all about hemp concrete let's get going guys i'm coming to you from a beautiful hill country job site here where we've got a building that is absolutely drop dead gorgeous under construction japanese inspired architecture and in fact the timber frame the skeleton in here is timber framing from japan that the wood itself is three or four hundred years old we're actually not sure how old it is but let's first start talking about this right here which i think is super interesting this is hemp crete and i actually have the main man here maddie matty with hemp attention you're the contractor on the hemp crete but you're also kind of the north american hemp creek guy right and you're actually selling these materials to other builders who are building with it tell me about this what is this yes what we're looking at here is a hemp crete wall system it is a combination of industrial hemp the wooden core of it okay and a specialized blend of limestone okay so uh let me break that down this is the bag of the hemp and that's what this looks like it's it's kind it looks to me almost like a wood fiber like i was about to make osb or particle board or something right it looks just like wood chips matt and then this is a for lack of a better term a cement right a binder it is a binder and it has a component of natural cement and limestone in it okay and you're mixing that in a big kind of industrial mixer on the job site maybe two yards at a time and then pouring it into a form to get to get this it almost looks like rammed earth or some other type of kind of built up product is that right yeah that's right and really the first thing we do when we mix these together is we add water we mix it with water it's a very controlled amount of water we bring that over from the mixing station to our wall and we tamp it in forms which is why it has that rammed earth aesthetic but this is not a structure wall right there's actually some structure embedded in this wall is that right that's right as of now it's treated as a non-structural wall infill material that's also highly insulating so this is our insulation this is our sheetrock it's multiple materials in one wow okay so this particular wall section here maddie we talked about this earlier this is like 10 inch thick right inches thick and in the center of that is a 2x4 framing which is the for lack of a better term the bones for the building it's the structure and then the hemp create that you've made on site that you kind of mixed on site is the muscles and the fat and all the other tissue that makes up the body of the building and then will this be left exposed on the outside this will not be left exposed it's going to get covered with a vapor permeable lime based plaster usually in two to three coats and that's going to give this product a long lasting life okay so almost like a sort of like a stucco finish right not a non-painted stucco looking finish on the outside lime plaster can be used inside or outside one cool thing about this architecture you've got overhangs everywhere um but what are the what are the kind of big properties what do people like about this hem creed what what is it that compels us to use this well first off from a building perspective it's really insulating about our 2.5 to r3 per inch depending on your mixture nice that's pretty good so we've got an r30 wall right here we got an r30 wall that's a big deal the second thing is an environmental reason industrial hemp when it's growing when and it's harvested on a two to three month cycle it's absorbing carbon dioxide from the atmosphere and storing it into the hemp stock itself we combine it with our binder a reaction occurs that also seeks carbon dioxide from the air and actually stores it in the wall so we've got a carbon sequestering thick insulated wall here isn't there some fire benefits to this as well that's right uh the fire benefits of hemp creek is that it's 100 fireproof it will not burn we could take a torch to this we could try all day long it will not catch on fire dang that's pretty cool there's a lot of benefits to using this no i made kind of the uh uh not inflammatory but the the bold statement that this was a fluffy marijuana wall it's not really marijuana for for those of you who are going to comment about that let's preempt that what's the relationship between industrial hemp and marijuana to really simplify it industrial hemp is sort of like the sober cousin of thc producing cannabis it is used as an agricultural commodity it's been used since the beginning of time to make ropes sales that brought explorers to discover the new world it's used in all sorts of products and primarily industrial applications and are there are there companies today that are using industrial hemp in in fabrication or manufacturing that you can think of interestingly in europe a lot of automotive companies are using hemp fiber in automotive panels there's now companies in the united states that are making hemp wood replacements for your conventional wood based products even hemp bioplastics are becoming a new tangible idea wow very interesting so so this hemp this industrial hemp it's a plant that grows in a field you're stripping the outside and that core that stock that as i said earlier kind of feels like a wood chip almost is what we're talking about here there's this really has nothing to do with marijuana except that it's a cousin uh product or cousin plant i should say to that but there's nothing here you can smoke that you can get high on or any of that kind of stuff this is the sober cousin that's right i like that term right maddie let's transition to actually showing people how you form and for lack of a better term pour this okay so we got a fresh batch of hemp crete made right here let's take a look at what the form boards look like now if you look at the outside of the finished wall you can see there's kind of a strata going on almost like a rammed earth project and this has some similarities this is the form board right here they're basically doing this in two foot lifts or two foot sections so we've got a poured section down below here you're going to notice the electrical conduits in we've already run that the electrician's been here you're also going to notice that the structure is inside the middle of the wall now most of the walls are framed just with two by's and in fact two by fours on a lot of the wall but this particular particular section of the wall is a shear wall section and the engineer has designed a moment frame this is basically just a u-shaped piece of tube steel that's been welded together and bolted to the foundation and that's going to keep the shear value the building from racking now what's interesting about how they do the form boards i think is these form boards need to be released later and so they want the minimum amount of attachment that's going to hold it while it's being formed but also to be able to remove it without a lot of damage now they're using kind of an interesting product they're using fasten masters timberlock screws if you're not familiar with these we use these a lot in construction you're going to be able to replace a lag screw with this but what these are doing is just giving us a temporary hold you'll notice they're putting a fender washer on the outside so they can get some good bite on this osb plywood this is three quarters inch thick so it's nice and strong and then to make sure it's spaced off correctly they've got a piece of pvc pipe here that's cut the correct distance i believe these walls are somewhere around 10 inches thick although this one i think might be slightly thicker and they're running it from this post right here which is a structural and also beautiful post that they're going to express and then on the outside here this is going to be a door so they just have a piece of osb as the form there as well now the other thing that's interesting is this won't grab on to uh to steel just smooth steel what i'm talking about is the hemp creek that is so what the engineer did was they they've got these bolts that are actually welded on as a tab and that's going to give that hemp crete something to actually bite onto now currently the hemp crete is not given sheer value for this project the engineer is not relying on that for shear but i think that in time as we use this more in america probably engineers are going to get more comfortable with it they'll be able to assign some sheer value because as you as you touch and feel it it's very hard it's not as hard as a cement or you know a concrete wall let's say but it's got a lot of um it feels very stiff there seems like there's a lot of mass on it and then when these form boards get replaced eventually on the inside and the outside they're going to put a a plaster a lime-based plaster on here so that this what you're seeing here with the strata this isn't actually the finished look maddie walk us through what you're actually doing putting the hem crate into the forms yeah so we've got our hemp cream in the buckets and what we need to do is first we're going to dump some in but it's a controlled amount we don't want to over pour this is a very controlled process where we build in layers so what i'm going to do is i'm going to put this bucket on the edge of the form board carefully dump some in here that's step number one step number two is we rake it out level because we want to build up in even layers after we rake it out level we then grab our tamping tools we take the long side of the tamping tool looks like a little homemade tool right there he's a totally homemade nice man yep and we take these we put them right on the edge of the form board uh we're packing really firmly along the edge of the form board but we're leaving it looser in the wall okay uh and you're not like putting body weight on it it's more like a tamp yeah it's more of a tamp um you know this is kind of a marathon it's uh you don't want to do something that's so labor intensive and and you know you're pounding it too hard this is more of just a you're stamping the edge so when we move through this what you'll see is a stamped edge along the form board and it's looser in the middle awesome let's do it man show us what to do uh and so you've got the sean on the outside and you on the inside so that you're kind of uh even yeah we're working together on this wall because we have these steel posts yep the shear posts in the way a lot of times we'll fully sheet one side and work from the other side that's kind of a more efficient way of doing it but this is a little bit too far over reach so we've now got this material in the wall i'm gonna rake it out spread it evenly and you're looking to go about two inches or so is that what you told me two inches is about where we want to be and you're just using your hands to kind of level it out there's no special uh love it doesn't need to be perfect it doesn't need to be perfectly level um and a you know lower portion of the form board we can just stick this in and use this as a rake so i'm going to start down here we have a removable form board so we want to have a good tamp edge so take the back side of my tool here really press that in and then i like to use the long side of the tool i'm just going to work right along the edge of the form board you can really start to see that stamped edge coming out it's one of the things that you're is so noticeable when you walk up to these walls uh maddie they're so crisp they're really flat your form works really really nice my assumption would be your whatever however good or flat your form work is ultimately means however good and flat the wall is going to be right absolutely absolutely form boarding is really key to having a good high quality finished product yeah after i tamp the edge there and you can really see that stamped edge sometimes i'll just take my hand and just gently kind of tap that yeah you're hand tamping hand tamping and that's the process right then you're ready for the next lift yeah this definitely takes some time doesn't it it sure does if you're not bothered with the uh random youtube crew how long would it take for you to do a two foot form board section like this normally for you and desean uh depending on the run you know maybe uh 30 minutes okay if we're really cruising you know 20 minutes it's not bad what really determines how long this takes is how much is in the wall you know if we have electrical conduit and things that we're working on we really need to be conscious of that so we're working around it really carefully makes sense so now you can see that when i dump this in it's kind of gathered to the back what i want to do is just rake pull it down the wall okay leveling it out and level being a relative term yeah it doesn't need a perfect level and i'm also tamping pretty firmly over here because this green form board is temporary it'll be pulled off and we'll actually see the hem crete return into our window buck right here actually our door buck i should say and there's no release agent on these forms right you didn't have to put wax or anything else like you would if it was a concrete form correct we can just uh pull the screws off and this form will come right off people often ask how long until you're ready to move the forms you can remove the forms as quickly as you can form it generally we like to always stack another form board on top you started level you're going to continue exactly we just continue level up the wall and this is basically just a half rip of plywood right it's a two foot sheet ripped in half yeah so we're using uh yeah three quarter inch osb ripping it red in half but on sides that are less difficult to work around we'll just take four by eight sheets we don't even need to rip them down and we'll just go all the way up those walls over there were completely formed on the inside so we were all on the inside and uh so those big long runs you're able to get a four foot section in there as long as you can reach down in the middle of the form absolutely cool now what are those white wood boards in there doing that was a joke that was a joke guys so cool to see how maddie and the crew from happy texture formed and poured this it is a beautiful cake that you baked here my friend but the rest of the architecture here is pretty stunning as well what's going on with this house give us the back story here matty the backstory is that this is a minka house it's a post and beam from japan about 350 maybe 400 years old shipped over in parts and pieces and reassembled by a team of japanese carpenters damn these guys didn't have any electric saws they used mallets and hand saws so all the timber we're seeing inside that's like 400 year old japanese timber that some japanese carpenters came in and assembled here on this texas site that's right now it's got a new life wow now who who's the designer here so the designer is axel vervut a belgian-based designer and he worked in collaboration with mood architecture a firm out of belgium and then also a local architect mel lawrence architects here in austin texas mel's a fantastic architect and then who's the builder here on site the builder is chad burnell with earth in motion gotcha man beautiful um are these this cedar that you're seeing on this porch that's we see that all the time in fact we're among cedar trees all those trees just to the left are all cedars did you tell me earlier those are all locally sourced they were all sourced from the property that we're standing on right now they went out and found trees with the right caliper size they had an industrial pressure washer pressure washed the bark off of them so it is all from the property so all those posts and all the rafters are are straight from this ranch that's right here man that's really cool what a story um tell me about a couple details you know as i'm as i'm walking around this house the first thing i thought was how do you install a window and door on this you know you're probably not going to take a screw into the hem creed right that's right that's right yeah so with our frame being inset to the wall or on center as we call it we're going to use a flangeless style window that's going to be basically set into the window frame backer rod and sealed around it and the lime plaster is going to return right into the window so it'll be a real clean nice looking aesthetic gotcha that makes sense so you're going to use like a shuco european window flangeless we're going to screw right through that jamb into that 2x4 which is right in the center which by the way it means we've eliminated all our thermal bridging this is going to be a really high performance house it also has some mass to it as well so that that thermal mass is going to want to stay the same temperature as well as have a bunch of air pockets in there which are making that high r value for the walls how do you insulate the roof on this project patty this roof is rather unique there's two layers of our product called hemp wool it's a fiber bat insulation made from plant fiber from industrial hemp okay 92 of the overall content of it is plant fiber there's two layers of that to reduce thermal bridging which is our 40 right there and there's two layers of gutex which is a wood fiber board from germany i saw that when i was in germany at the bow show that's not that's totally almost unheard of here in america but pretty common when i travel through switzerland and germany it's an amazing product and yeah and then of course on top of that you've got this gorgeous cedar shingle roof too or cedar shake roof i should say i mean it's going to be an incredible incredible architecture when it's all done tell me about what else you can do from hemp right because you mentioned you've got hemp insulation that's more like a traditional bat insulation are there other ways that you could use hemp cream yeah so really the easiest way to incorporate plant-based building materials into your home is probably using hemp wool but there's other products we can spray apply hemp crate we source hem creek building blocks from other countries that are making them on a large scale so we have these different options here in the united states so we can now start using i love it you've got a couple mock-ups on site let's go check out those mock-ups all right maddie so you got a couple mock-ups that you built before construction started let's talk through these three what is this first mock-up so this first mock-up is using hemp creek building blocks they're mortared together this is actually a two foot thick wall assembly damn a lot of r values and so how big is this block that we're seeing here that's made out of hemp the block is about two feet by one foot okay and what are you using to to mortar them together we're actually using a hemp cream binder the same stuff that we're using in our cast and place recipe we're using to mortar the two blocks together gotcha and then what is this that we're seeing here is the final finish this kind of stucco looking product yeah so this is a breathable lime based plaster that's usually applied in two to three layers so this is a weather resistive coating that will last for the life of the building wow beautiful and non-painted it's all color integral i'm assuming right yeah actually you incorporate a little bit of pigment into it and so you can see we do have some kind of color swatches on this wall where we've got different pigments incorporated into that final coat so that it's tinted however the client desires gotcha now this is not what you built with though this is just an option and this mock-up is actually pretty similar to what you built with or is the same wall assembly is what you used right this is very much so what we are doing right next door in the minka yep so we've got a 2x4 right in the center you can see in front and behind that we've got a couple inches of hem crete so those two by fours are buried in the wall so to speak but because that hem crete is for i hate the term breathable but it's the term that we use it's vapor it's vapor open meaning if it gets wet it can dry to the inside or the outside which really means that you could use this in any climate zone that's right that's right and one of the amazing things about this is that this has been sitting outside unprotected uncovered for over a year oh wow and it's not breaking down it's you would think that there might be some uh degradation of the fiber or um or maybe even um what's the word i'm looking for decay right of the hemp and that's not hot that's not the case that's not happening and what we're also not seeing which is huge is no mold oh that's right and it's sitting out too and there's no mold and there's no decay why is that why is that fiber from the plant not decaying or not molding that's a really good question matt and the short answer to kind of a long uh question is the fiber itself the core is petrified it is essentially made inert by the process of being mixed together with our binder okay which has a high alkalinity making it resistant to mold and that organic aggregate becomes a lot less like plant matter and a lot more like a stone and that's also why you guys are wearing ppe right you're not touching that with your bare hands you've got long sleeves on because that lime if that gets in your skin is really going to irritate you it's in effect could burn your skin right that's right and the other very critical element of that equation is you know we're always making sure we have uh face protection on we're protecting our lungs our nose mouth uh while we're mixing hemp cream got it what's the last mock-up so this last mock-up is a little bit of a different sort of style where we have a frame shift it to one side it's using a different kind of binder and hemp these mock-ups did kind of play with different types of binder methods but this was primarily done just to see what hem crete would look like flushing out to studs because we do have some partition walls inside where we're just infilling in between the partition walls as opposed to burying that frame on center to our wall but if you wanted to vary the way you did this on the outside is your full hem crete that has plaster on it right and that could be your exterior finish and on the inside if you didn't want that you could hang drywall you could do other wood finishes or whatever and have your studs to the inside of the building which also would be a good assembly and this is kind of interesting look you've got a little mold growing on your wood but there's not that growth on the hemp creek as well you know this does bring up one interesting question i saw in the building all the way around that your bottom plate that two by four treated bottom plate is wrapped with a you know a vapor barrier for lack of a better term a plastic asphaltic flashing tell me about that why is that yeah that's a really good question matt what we don't want to have happen is moisture to migrate up through the concrete into the hemp creek wall so it's essentially our damp proof course that's going to be popping provide a barrier between our concrete and the hemp create above right so you wouldn't just pour a slab and then go hem creek right above that you always want something to uh to stop that rising damp that's right and be a capillary break as well and then also that bottom plate's giving you the structure to land on and then i think you told me earlier where you're seeing that protector wrap on the outside of this other building you're gonna put a lath over top of that and then the plaster will just cover that you won't see that it'll be invisible maddie impressive man your crew top-notch the architecture here beautiful the builder's doing a great job so fun to meet you man how can people get a hold of you if they're interested in any of these products or doing uh hem create on their project the first place to start is to visit our website www.hempitecture.com we've got a lot of information a lot of resources there we've got youtube videos where people can learn and see is this right for me is this something that i want to explore and feel free to send us a message through our website we'd be happy to get back to you and learn more about your project and how we can help you out yeah and also i'll tell you guys uh maddie's got an awesome instagram feed with some gorgeous pictures of this job site that i stalked that's one of the reasons why i got a chance to get out here just to clarify this is not a sponsored video we've not exchanged any money i just thought this was really cool so guys go check out maddie's site if you're not currently a subscriber to the build show though we publish every tuesday and every friday and oh by the way on build show network we have five new videos a week so go check that out as well follow me on twitter instagram otherwise we'll see you next time on the build show [Music] you

Channel: Matt Risinger

Views: 568,267

Rating: 4.9282026 out of 5

Keywords: Matt Risinger, Build Show Network, The Build Show, Build, hempcrete, insulation concrete

Id: cm23l_VLyp4

Length: 25min 16sec (1516 seconds)

Published: Fri Sep 11 2020