Insulation for Masonry Buildings - Historic Retrofit

we're talking today about how to insulate and renovate a full masonry building we're at our West 10th Street project and remember this is a historic 1876 build house with two-foot thick masonry walls I've got my friend Christopher when Christophe is an engineer and a building science geek like myself Christoph's company does some really awesome stuff for me they do mechanical designs modeling testing all kinds of building science related work and we wanted to have a conversation today about how to remodel how to upgrade the efficiency of this house and also how that might relate to somebody watching this video who's in another part of the North America's you know there's so many houses like this that have either double why they're triple wide masonry walls maybe that's CMU maybe that's other materials not necessarily Rock like we have on this house but I think this video is going to be applicable a lot of people so as we renovate this Kristof water what are the first two things when you talk about here well we're thinking about control areas and we're thinking about mass effect mm-hmm control airs are as you know in priority order what's the first one water bulk water bulk water say we want to make sure that the roof is in good shape that it's shedding that if there are gutters downspouts that are sills or door sills everything that is intended to shed water to the outside is working yeah next one is airflow airflow we want to make sure that we recognize that though it doesn't seem like it air can flow both around this assembly and through this assembly there's cracks as they're visible over here carrying with it a lot of water water is the third one vapor water vapor moving through this wall as massive as it is it is open when it comes to water vapor water vapor can move from the outside in and that is where it is here in summertime in Texas so a quick example that meaning if this if this rock wall gets wet on the outside from rain or sprinklers that moisture is gonna migrate through the wall and it could add humidity to the house correct absolutely yes so it's hot and humid outside cool and dry inside hot to cold wet to dry both drives are toward the interior gasps absolutely right and what's that last control air so that's the one thermal control air that's the one about comfort that's the one about mainly all about the occupant all about energy use in terms of durability of the building it was done before you got to thermal control but what we had here is you know if you look at strictly as our value you have a pretty abysmal situation we have maybe in our to I mean probably not even in our to that's optimistic but in terms of comfort it was still working because this wall because it took a long time for the heat to move through it it stayed cool for the long portions of the day and because it's cooler than you you radiate heat to it you lose heat you feel cool so that cooling effect was happening here where does that heat go right we just talked about you radiating to the wall well at night in an area where it gets colder at night well by then the heat from the day might be radiating to you to warm you on the inside here in Texas what we would really hope is that this is the after a temperature that as the heat of the day gets colder that now the drive is from the inside to the outside so that heat goes back out that will happen many days of the year clear summer nights when the night sky radiation can suck the heat off of the building we'll get that effect on this but generally speaking the diurnal effect is the dominant one yeah for the effectiveness of a mass wall and that's not well understood IEC C treats it very kind of broadly they don't talk about diurnal effect and if it is not the night sky or not the cold outdoor conditions that are cooling this wall off at night what is it it's your mechanical system huh again kaboom you have a benefit here you have your mechanical system operating at night there's less load on the building the mechanical system is operating more efficiently at night so it's cooling off the building more efficiently so this mass wall is working for you which brings to the point of what do we do with this house you know we talked about early on in this project how do we insulate it how do we increase the efficiency and I think for a cooling dominated climate if you're in the south you know it actually makes sense to take full advantage of that not insulate on the inside the ideal place to insulate would be on the outside yeah you know do do a let's say a weather resistive barrier that's fluid applied on the outside at an air space and also get some great rigid foam insulation let's say in the outside right but here we've got a historic building I've got a plaque out front I could not change the look on this one we're gonna insulate the heck out of the roof you know we're gonna do a great roof line with a rigid foam on top with spray foam on the inside we're gonna make it super airtight we've got good shade from this house with this three sided porch yeah we're gonna also make sure we've got a good metal roof on the outside that's going to provide a good radiant barrier so we're gonna add a ton of insulation there and your company's doing the mechanical design for us we're gonna be using a V RF system here that's a very high efficiency talk to me about how that mechanical design integrates with with a house like this with the thermal mass so the thermal mass is going to introduce load variations over time that are gonna shift basically shift the heat load to later in the day that's how it's going to help yeah that's gonna work efficiently whether you have full load or part load okay in last topic that we want to do we want to jump into is what would we do differently Christoph if someone who's watching this in Michigan has a building that's similar to this how would how would we do this project differently right well the the biggest difference there the most important one to take away is where you would put the vapor barrier vapor control layer you would move it to the inside in those heating dominated climates okay Minneapolis something like that here we would prefer it to be on the outside so in this case how would we can you give me a couple of assembly ideas on how we might do that on a house like this full masonry sure yeah you could either be applying a surface to to this material itself mm-hmm a dimple mat drainage mat with a ventilated rain screen and then insulation on the inside or you could do what's more commonly done is you would just build a stud wall right here yeah and that stud wall would afford you the opportunity to insulate it and to detail the air control air carefully hey Christoph thank you so much for joining me for more on Christoph and his company his website is positive and Energy Pro correct and look up his podcast they publish new content about every two weeks it's the building science podcast available on all the major outlets including iTunes out there and stay tuned for more from the build show this house we're gonna be publishing some great content from here look for hashtag West 10th and of course check out our social media links hit that subscribe button below we'll see you next time

Channel: Matt Risinger

Views: 40,715

Rating: 4.6766915 out of 5

Keywords: masonry, insulation, renovation masonry, rock buidling, rock building, mass wall insulation, insulation masonry, insulate rock

Id: Y-8vGkQwMoU

Length: 7min 9sec (429 seconds)

Published: Fri Mar 18 2016