637: Joe Lstiburek, Ph.D., P.Eng - Moisture Control for Residential Buildings

[Music] this is iaq radio indoor air quality radio the voice of the indoor air quality industry with your hosts radio joe hughes and the z-man quizzlotnik and now radio joe hughes good day and welcome to iaq radio plus this week we welcome back dr joe steve brooke we're going to talk today about the new book moisture control for residential buildings our last show was a popular show on the life and times of the dean of building science our last live show that is we're back live this week with dr steve before we get started let's thank our sponsors they are the reason we can continue doing this show our marquee sponsor is instascope at instascope.co our association sponsors are the american industrial hygiene association at aiha.org the american conference of governmental industrial hygienists at acgih.org the cleaning industry research institute at science.org the indoor air quality association at iaqa.org the restoration industry association at restorationindustry.org the institute 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investigations at tsi.com here's today's iaq radio trivia question name the building-related non-profit non-government organization established by the u.s congress and the housing and community development act of 1974 public law 93-383 back to you joe all right dr joe stevreck is the founding principal of the building science corporation and an ashrae fellow he's a building scientist who investigates building failures his doctorates in building science engineering from the university of toronto he's been a licensed professional engineer since 1982 and the wall street journal referred to him as the dean of north american building science dr steve rook is an acclaimed educator who has taught thousands of professionals over the past four decades and has written countless papers welcome back joe great to have you here it's an honor and pleasure to hang with you and the z man personally and of course in canada he's the zed man the zed man right i mean i like listening to zed's at top [Laughter] i'm not familiar with that one dude all right we're talking about the moisture control for residential buildings there was a a book originally in 1991 a revision in 94. why are we writing a new book at this time joe well um the physics hasn't changed but uh our understanding uh of what's going on has gotten better and more significantly um the materials are very very different we have an awful lot more engineered wood and i view engineered wood as an insult to both wood and engineers you know osb is spam is the osb of luncheon meats and and i you know i remind people that we used to you know go to forests and cut trees down and cut them into boards and build boats out of them and sail them around the world try doing that with a sheet of osb and the other thing is that we're insulating up the wazoo and that's a metric term it's two yin yangs and and uh that has significantly improved the thermal performance but it has a huge negative impact on durability and the reason is is that if things get wet and they subsequently dry no problems you know wetting folded by drying hey relax take a valium but drying is an energy exchange so you can't have drying unless you have an exchange of energy so what has happened to the drying potential of our buildings as we've increased thermal performance it's crashed so if you want to build a building with an exceptionally low drying potential because it's ultra insulated then you have to reduce the wetting potential so you have to stay in high grip or moisture balance and so as we've doubled and tripled our thermal resistance and performance in both heating and cooling climates we've had to double our ability to keep the darn things from getting wet so i mean the easiest example is that there are only two kinds of windows in the world windows that leak in windows that will leak so what do we know about windows well they leak it gets worse windows are like people as windows and people get older we leak i remind you youngsters you have no freaking idea what's going what's happening to you um in the old days the we call that leakage incidental water it's a leak in and to a wall assembly built out of 1000 000 year old trees and rocks and it you know dried in both directions who cared now it's not able to dry and that incidental water is no longer incidental so the industry has responded correctly we completely pan flash the underside of our windows otherwise we we wrap the entire opening so that when that inevitable leakage of the window and the window to wall interface occurs we direct the water to the outside we basically say a leak is not a leak if the client never sees it and if it never does it doesn't get into the wall so accept the fact that things are going to leak just kick the stuff out and that's obvious and logical now but it sure as heck wasn't obvious and logical uh back in the 90s remember synthetic stucco eiffs water didn't go through the synthetic stucco it went through where the stucco was connected to the windows and the windows themselves went through the punched openings so in other words oh my god well we never had to care about that before well yeah but now we have so little energy available and we're building out of materials that are moisture sensitive whoa things are different so you know after 30 years the department of energy yelled at me and called me names and terrified me and said rewrite the damn thing so there you go beautiful but john let's put up the table of contents for the new new book i think it's interesting how you broke it down joe it's a little different than it was broken down in the past it seems like a combination of the fundamentals and then the eeba books the the climate zone books here um you know you go over the water molecule materials and mold moisture movement wall assemblies roof assemblies foundations mechanical and then through the climate zones why did you set it up this way well it's kind of hard to give people advice if they don't understand what the advice is based on so why not give a background into the key fundamental principles once you know the fundamental principles all of the details become obvious and the details are just guidance because then if you understand the principles you can revise and modify the details based on your own individual constraint and experience and available materials if you just say here do this people are not going to know what they can change and what's important not to change um so that you know that it's called wisdom it happens when you get older so 30 years ago i screwed it up and stopped fixing it all right so there you go all right well what you mentioned the most what is the most important moisture concept or controlling moisture concept in residential construction i'll accept the fact that buildings are going to get wet and designed them to dry we we got the focus wrong before a lot of people also wanted to prevent wetting and i said no no we should encourage drying in other words the focus should be more on drying than on just the prevention of wetting because a lot of the concepts on the prevention of wetting prevent drying so i want to reduce wetting but i don't want to do it at the expense of reducing drying and that it only took a you know a decade or two for me to but jeez you're an idiot you know you know it's a balance you know wedding and drag and so i mean the fundamental principle is is when the rate of wetting exceeds the rate of drying you have accumulation and you don't get into trouble until the quantity of accumulated moisture exceeds the moisture storage capacity of the material system or assembly and that is time temperature and material specific that's it that's that's the summary of the entire freaking book and i should have said that like 30 years ago but i didn't um not not clearly anyway and so now it's like okay let's look at some of the principles well what what gets wet with most well rain and groundwater well what's the biggest rain source well where the building touches the sky followed by the building touches the ground and then the sides you know if you can't handle the rain above grade and the groundwater below grade give up then you worry about air you don't worry about air until you handle rain then you don't worry about vapor until you've handled air you know that's the order you know do the important stuff first so i i have a lot of a lot of fun i got uh invited to um abba the air barrier association of america and and i was a keynoter they by the way they not invited me back maybe they didn't like my humor but i said why would you a name yourself after a bad swedish musical group and and and b um you should have been called waba the water barrier association of america before you recall the air barrier association of america because all of your air barriers are really water control areas that have an air control function that's been added to it so interesting i got polite applause and uh nobody bought me a drink and you know here i am by myself again hey john throw up that first detail of the uh the climate zones high growth thermal wait let's let me let me do it right the hydrothermal regions as outlined in the book joe why is this such an important detail in your book figure 1-1 it must be important you know okay a building has to resist certain things it's an environmental separator it keeps the outside out and the inside in and what are the odds that it does things perfectly well sometimes the inside gets into the thing that separates the inside from the outside and you have to decide to kick it back or let it through sometimes the outside gets into the thing that separates the inside from the outside you have to decide whether to kick it back or let it through and how much you kick back and let through in each direction depends on on four things the first is where is the building located the external environmental load that's what this map is the second thing is what's what's going on inside because that establishes the internal environmental load the third thing is what are the materials that comprise the environmental separation are they rocks or they was wet and number four is what's the energy flow so the very first thing that i want to show is let's establish what the external environmental load is and in montreal which is you know very cold there are only two seasons this winter and last winter in wyoming they're only two seasons hot and wet and hotter and wetter well that might be pretty freaking important so this is a map of what the external environmental loads are and um this map was stolen by ashrae and it became the ashrae guide and then it became adopted by the i ecc and the iecc instrument their climate zones so you should ask me where i got it and where did you get it joe i stole it i stole it from i stole it from a long dead russian uh if you're gonna steal stuff from russia you better make sure that the russian is dead um this is a this is a variation of the copen climate uh chart and you have to laugh because that was a base that's basically on vegetation it basically explains it's a map of the plant kingdom on the planet and so i came to the conclusion that the plant kingdom was a better judge of temperature rainfall and humidity than architects and engineers good good and then show the next one john because this is another interesting i love this graphic of precipitation um again looking at you know what's the external load on the building give us a little more on this one joe well you know rain is important there's a there's a big difference between salt lake city and key west florida right yep vegas versus biloxi mississippi right you know and so i i said look let's we need a temperature humidity map which was basically the first one which is taken stolen borrowed from copen and then i wanted one for rainfall and and so nothing exis nothing existed so i you know said look let's i'll create my own map and and so i've got zero to 20 inches 20 to 40 40 to 60 you know 60 and above 16. you should ask well why did i pick increments of 20 because when i picked increments of 10 the map was too complicated when i picked increments of 30 the map wasn't complicated enough this felt right and so are you telling me i got this based on feelings well yeah it was the song feelings and so this was the iecc climate zones basically uh moist marine and dry it's based on this rainfall so i mean i i look at the code and i'm like hey that's me baby and it's kind of it's kind of it's kind of neat so you need to know uh how much it rains and what temperature humidity there is i mean there's more to building than just that i mean it's probably important to know whether you're in an earthquake zone or a hurricane zone and wind loads and everything else but you know the the structural engineering profession is very mature compared to building science right we're we're young they're old they they got this dialed in that's why not much happens in structural engineering uh that's why they're so boring you want excitement talk to a building scientist because nothing works and we blame the architect john let's go to the next detail we have on thermal bridging at a wall floor intersection and i want to ask you joe why is thermal bridging seem to be coming more and more important yeah you you can't build an energy efficient building if you've got a thermal hole in the wall that angle iron that supports that brick veneer is is is probably responsible for almost half of the thermal losses and it's funny so let's you know cover it with continuous insulation and the continuous thermal insulation is you know going to be still doesn't affect the the angle irons you lose almost 40 percent because of the thermal resistance of the angle iron or the thermal conductivity of the angle iron at at the slab so we we've we've had to basically to make this logically work we have to take the angle iron and offset it hang it off the wall on brackets to get any semblance of thermal performance in these buildings so it's a bfd and and you know the the f is from the president i understand uh joe well let's talk about condensing surfaces so what is the first condensing surface now in in today's construction well all right it's always it has always been and it always will be the back of the sheathing and i i i laugh hysterically when people say well we're going to do a dew point calculation and i'm saying well why well we want to know where the dew point location is well we always know where it is it's on the back side of the dam sheathing well no no the dew point temperature is reached in the middle of the fluffy insulation and i'm saying but you don't get condensation there huh all right you're gonna love this because we used to teach this in high school but not anymore if i have one pound of water and i want to change it one fahrenheit degree i have to add or subtract one british thermal unit one btu right duh well wait for this do you realize that you can have one pound of water at 32 degrees fahrenheit and one pound of solid water or ice at 32 degrees fahrenheit is that remarkable and to change one pound of liquid water into one pound of solid water at 32 degrees requires you to remove over 100 btus whoa now it gets even interesting so i have one pound of water in the vapor form and i want to change it into one pound of water in the liquid form i have to remove almost a thousand btus wow one degree one btu versus a thousand btus what happens is that when you have a change in phase that energy has to go somewhere and the fiberglass fibers and the cellulose fibers do not have enough thermal mass to handle the change in phase energy you need a condensing surface with sufficient thermal mass to handle the change in phase energy for condensation to occur well the first surface is the back side of the damn sheathing we've never had to do the damn calculation if you actually read the fundamentals it tells you that but nobody reads this this is amazing you know like really you know the tell when you want to know if a mechanical engineer actually knows anything about building science or just calculating stuff is well we need to do a dew point calculation in which case you know smile politely and look for somebody else oh joe looking at moisture transport that's the big thing what are the four moisture transport mechanisms uh that predominate in building science well thank you for that softball question it's like being being the president being interviewed by abc news [Laughter] it's a bfd number one number one it is rain and groundwater all right so it's we did that yeah liquid flow number two is airflow because it transports an enormous amount of water in the vapor form number three is molecular diffusion vapor vapor carried by molecules going from one place to another because of a concentration gradient not molecules of water vapor being carried by air air transport for vapor is a hundred times that's an order order of magnitudes greater than by molecular diffusion so you had vapor flow by diffusion and then then you basically deal with thermal conditions so liquid water air vapor and all of those are affected by the energy which is the thermal all right john give me that 313. i want to talk about draining the building and then what we call a screen assembly or what you refer to as a screen assembly joe this is one that you've been using for many years and and i love it i mean it's basic it's simple but i think it's so important and a lot of people don't get it well the water drops on the top of your building you want to get the water away from your building you want to drain the roof to the ground and slope the ground away from the building make the water go to your neighbor's property give them the grief all right just layer mask the building in such a way that each successive attachment is designed to direct the water farther away and and man this is only a 3 000 year old principal so it's bound to catch on at penn state [Laughter] john john go to the next one i want to talk about screen assemblies joe this is a roof intersecting wall wait is this yeah uh there you go tell us a little more about the draining of the rain from the plane down and away from the building as i recall you used to say it was onto your neighbor's property i forgot well you need to you need to drain the rain on the plane and don't be a dope slope and if you want to save cash flash i've made a career out of those all right three engineering degrees and and you have three phrases yeah that's you know they're they're they're there you go um draining the wall is a big deal which means you need a surface that doesn't have many holes in it but it's not the holes that are the problem in the surface is that if you have a force to push the water through the holes you get into trouble and that's hydrostatic pressure so if you provide a drainage gap you don't build up hydrostatic pressure so even though you might have nail holes and staple holes you're not going to have the water push itself because of its weight through the hole the biggest issue is where you have for example a roof or a sloping roof the water is going to run down that intersection when it gets to the edge of the bottom of the roof you need something to kick it away from the wall you need a kick out flashing if you don't do that you're going to drain the entire roof into the wall and the wall is not designed to handle that you know it's called a wall it's not a roof right i i know i'm legendary a wall is not a roof although the perfect wall can be a roof yeah with this kickoff flashing joe i i've looked at hundreds of jobs it's almost never there um is it how long is it betting code if it isn't code why don't people do it well um it's not in the code but it is uh in many regions now something that we call the standard of care which means it's a legal requirement if you don't have it there you'll get sued because they're going to say well you're an idiot you should have known you had it and by the way the majority of people in this particular area now do it and therefore you should have known they didn't do it in the past because you know we had high drying potentials and we had materials that were robust they were able to get wet now this is another one of those sources of incidental water that is no longer incidental so we've had to become very very targeted in identifying where wedding occurs and kick the water out hence the word kick out flashing this is amazing how we name things in such a way that people will understand what their function is wow john let's go to the next detail i want to talk about what you're calling a screen assembly joe i'm not i'm just not that familiar with that terminology tell me what you mean by a screen assembly well every cladding system leaks repeat after me joe radio and so what we need to do is provide a mechanism for the water that gets through the cladding system to be drained away so we need a drainage layer and i call that a drainage plane but for drainage to occur you can't smoosh that's a technical term you can't moosh the cladding directly against the drainage later you need a gap so you need your drainage space and that allows the water to drain out so it doesn't build up what we call hydrostatic pressure and the cladding is now a screen as opposed to a barrier it screens the water control layer but it's not and it's accepted it's not intended to stop 100 of the rain then we need to drain the rain on the plane would you like to know where drainage plane came from sure came from me and betsy when i was dating her we loved musicals and one of our favorite musicals is my fair lady and the middle of my fair lady eliza doolittle says the rain in spain stays mainly on the plane i turned the betsy and i said we need to drain the rain on the plane and she said where's that damn rain so the next day i presented to a builders association meeting and drainage plane is now in the darn code can you imagine this so you know so i get cross-examined during court you know testimony sometimes and i get the judge and the jury laughing when you say are you serious that drainage plane came out of a musical i said yes alcohol john put up the next detail this is a i think we have a screen assembly or a ventilated cavity example joe this is a beautiful it's so simple but i i see it wrong all the time well i mean here's the the big deal with uh with with with brick when it rains on brick the brick gets wet that's why we call it a a reservoir cladding you see it's you have to think of it as a moisture capacitor that is charged during a rain event then when the sun beats down on that brick the water in the brick increases in temperature and the water is going to want to go from warm to cold so some of the water in the brick is going to evaporate to the outside but a whole bunch of it is going to be pushed to the inside and that's why we need a moving stream of air behind it to intercept that inwardly driven water vapor it's called solar driven moisture so we want to back ventilate reservoir claddings that's a new jersey version of ventilated cladding yo we run into these all the time that we're done in the 50s 60s and the bricks right up against the exterior sheathing it's uh there's no there's no air outlet or air inlet as you have it described here which is actually i think you've added that recently that nice little detail there with the blue arrows um people obviously aren't going to tear off all the brick in many cases what's the fix or at least an attempt that affix when we run into this and they've got the landscaping up over the bottom of the brick there's no weep holes um the bricks right next to the exterior cladding how do we fix that i do what the romans did they stuccoed it they reduced them they reduced the water absorption well i don't like putting stucco over brick well okay well then paint the brick to reduce this water absorption i don't like the color of the paint well then use a you know cyaline or siloxane which is basically a transparent water reducing agent to reduce basically the water absorption to reduce the reservoir we have options joe really well would you ever recommend actually putting in some weep holes and just you know trying to air it out that way well i call that faith-based ventilation all right i got you hey joe we're going to stop we're going to thank our sponsors here real quick when we come back i want to talk about these water control layers in a little more detail so we'll be back in 90 seconds with dr joe stiebro our marquee sponsor instascope more jobs done faster with the future of iaq assessment technology unlimited samples instant results and cloud-based data at instascope.co our association sponsors are aiha healthy workplaces a healthier world at aiha.org acgih advancing careers of professionals in environmental health industrial hygiene and safety interested in defining their science at acgih.org the cleaning industry research institute see more deeply through science and research at ciri science.org the indoor air quality association promoting the exchange of indoor environmental quality information through education and research at iaqa.org the restoration industry association the granddaddy of the restoration industry network with leaders at restorationindustry.org the iicrc a non-profit standards development and certifying body for the cleaning and restoration industry at iicrc.org and healthy buildings america 2021 in honolulu hawaii november 9 through 11 at hb 2021 hyphen america.org iaq radio industry sponsors are aeml laboratories free shipping great pricing same day results with no rush fee at aemlinc.com particles plus feature-rich particle counters and air quality instrumentation count on us at com particlesplus.com wolf sensing solutions over 20 years manufacturing accurate reliable iaq instrumentation for portable short-term and continuous monitoring at graywolfsensing.com tsi inc an industry leader in precision instrumentation for monitoring indoor air learn how to expand your iaq investigations at tsi.com belt rentals availability reliability and ease for all your iaq and restoration needs at sunbeltrentals.com april air healthy air healthy home at april aire.com and healthy indoors magazine a free online magazine for industry professionals and consumers at healthyindoors.com all right we're back for the second half of our interview with dr joe steve brook joe i i i really quickly wanted to say um as far as moisture water control layers just if you could give us some examples of water control layers a house wrap that's a water control layer what other examples well they the original one the classic one was asphalt impregnated felt tar paper it's kind of funny the mississippi river divides the united states up into the the the half the eastern half we have asphalt impregnated felt the western half we have type decoded paper so believe it or not we have two different types of black dinosaur impregnated or coated materials but both of them are our water control layers then we developed the synthetic ones uh the most famous was uh tyvek but it wasn't developed for being a water control layer it was basically a fabric but give dupont amazing credit for creating a market for a product that they didn't have originally a market for um when we got into um fully adhered membranes uh peeling sticks and uh wr grace tremco vasf you know a lot of the roofing fully adhered things ended up on on walls and then we developed fluid applied ones liquid ones uh you know paint applied water control layers uh and and more recently most recently we're now integrating the water control layer into the sheathings themselves so for example huber zip has got osb with the green layer on it and now you're dealing with joints um um georgia pacific has got and usg has got gypsum board with a water control layer already integral with it so now you're just dealing with joints so all of those are our water control areas we went from mechanically attached to fully adhered to fluid applied to now integral and that process took i don't know a century and a half wow interesting hey let's uh cliff before i go do you want to jump in here yeah we have a couple of text questions joe that i'd like to post with you uh the first one is i was asked to ask you about magnesium oxide and other alternative materials like fast wall and duracell icfs which seem to handle moisture more effectively do such flow-through vapor permeable materials have benefit and a future magnesium oxide board has a history of being extremely unreliable because of facility and we had tens of thousands of square feet of roof failing um i believe that the germans and the irish have figured out how to deal with the chemistry but it's still you need to be careful um i now that i've qualified for medicare i'm very conservative in terms of the flow through materials in terms of vapor flow for example um you don't want to be too vapor open you want to you want to you know be goldilocks not too hot not too cold just right not too vapor open not too vapor closed just right because if you are too vapor open you will have inwardly driven moisture and if you are too vapor open you will have outwardly driven moisture and you might want to slow things down and not stop them so i'm a i'm a let's slow down a little bit and you know let's you know that's an old guy talking to you all right okay well the second question is i was asked to query you about something called buffalo pelt and uh where fur should be put and so on and so forth so i have no idea where that came from all right i used to tell jokes one 35 40 years ago when i first started and about you know when you are riding in a carriage pulled by a horse and you're wearing buffalo skin shouldn't the fur be to the outside or to the inside and so the short answer is is that from the you know fundamental principles you should have the skin on the outside and the fur on the inside and the the punch line of the joke was the guy driving the the carriage says well wow i'm just shocked that you know all those buffalo i had it wrong for all these years isn't that the truth going back to the uh the vapor control it seems to me that craft face fiberglass insulation was ahead of its time and didn't know it um or did they know it i am not sure i've been asking that question um over many drinks with many of the old people who a lot of them are now dying on me and i i you know i'm running out of people old people to ask that question so the craft facing is was what we call the first generation smart vapor recharger it changed its vapor transmission with relative humidity so for example under a dry cup test it's one perm under a wet cup test it's almost it's almost 20 perms so it's like a valve that opens and closes with respect to relative humidity and the question is is did they know that and um some a lot some of the old people did know that but i don't think it was designed that way in other words was an accidental byproduct that turned out to be quite spectacular or an accidental and an accidental property that people didn't know when they first made it but when we began to figure out how things were working it was like oh wow this is absolutely awesome and so the the way the reason that it was so nice is that back in the day in the winter time uh in most north cold climate houses the interior relative humidity was 20 percent so the valve was smooshed closed in the summertime the humidity went up to 50 or 60 percent inside and the valve open so in the winter time the wall was prevented from getting wet from the inside in the summertime it could dry in both directions well the craft facing is no longer a good idea because we're significantly increasing the interior moisture level in the houses in the wintertime so we're basically prying open the valve all the time so we needed to to shift the hook or the inflection point farther to the humid side and so we now have the second and third generation smart membranes which um are vapor closed until you get to 50 or 60 relative humidity and then they open up so but that was designed into those materials and and the person you have to thank was a hardwood council from the front offer and you should ask him over beer how he came up with it and i'll tell you anyway he was figuring out what is what's you know his father is a famous physicist a phd a doctor and he's in graduate school and he wants a topic to figure out you know what am i going to do my doctorate on and he when he got depressed he went to the beer hall and he's ordering a beer and eating sausage and he's poking at the sausage casing and he's noticing that on one side of the sausage casing there's bubbles over there and on the other side of the sausage casing there was bubbles over there and he wanted to know why and that turned into his doctoral dissertation and that turned into the first smart membrane and so when you look at intello and membrane the original derivation was a sausage casing in germany think about sausage casings that's interesting i'm glad i asked that joe uh let's let's go i want to i want to real quickly look at pan flashing a pro plan flashing approaches 323 john this is another thing that like you said earlier it wasn't maybe as important in older construction as it is today can you quickly run through the approaches here and then then i'd like to go to the uh drained window and door openings well um basically what we have here is that we're creating this under window uh gutter the most recent addition to this there should have been there should be a fourth uh uh piece and that is uh fluid applied right and and the idea is that we're creating an under window gutter so that when the window inevitably leaks we collect that water and kick it to the outside and so what we basically have are a back down and we have end dams and we wrap it around the face to connect to the water control layer on the exterior part of the sheathing or the sheathing itself this is a a really really big deal now that we have osb and an awful lot of insulation in the wall assembly all right so the listeners are hearing a little background noise which is perfect i don't know how you do these things but apparently you decided to have them come today so we could make them part of the show uh joe is getting windows replaced well you have to understand that i'm thrilled that somebody shows up okay i would have won i would rather blow you off people coming to the give you any idea how difficult it is to get anybody to do anything now oh i know joe i'm a car my son's a contractor it's it's insane okay so you know everyone let's go to the next detail so what i want to ask john go to the next one if you would what i want to ask is when you're replacing windows right now in the background we hear that noise what tips would you give people who are having window replacement done and you know we see how it's done all the time they stick it in the hole and they it and they hope for the best what are we doing a differently in your current remodel and how can we do this better well i'm okay i'm gonna pat myself on the back i'm doing it exactly the way that i did it 20 years ago because 20 years ago i did it correctly um and but it's now more or less standard practice i'm changing out the windows because i got shitty windows but the wind of the wall interface was pretty was pretty darn good the key element is you put in your pan flashing we've already talked about that but what people forget is you need a four sided air seal on the inside a big red dot on the inside it needs to be tighter than a scotsman in a bar all four sides because when the wind blows against your wall the inner seal causes the air to back up so you don't get wind-driven rain into that space then on the outside you basically seal the sides the jams and the head but not the bottom the reason you don't want to seal the bottom is we want the water to do what to drain out the bottom so you want pan flashing a four-sided interior air seal three-sided seal on the exterior and drain the rain baby and oh by the way slope it don't be a dope slope okay yeah you see that beveled wood in there that piece of beveled wood siding that's that's going to be your slope i think on this one how do we yeah joe i'll tell you my son does remodeling and and if i tried to get people to do this right uh we'd never get a job uh unfortunately it's it's a it's a tough situation where um the the people trying to do the right thing is it's just so much more costly than you know the anderson window and nothing against anderson window but the ads they have on every day about replacement windows and how cheap they are well so i i'm i'm gonna get into trouble for this but what the hell i mean you know we live for that all call me names um the most effective technology transfer mechanism in construction is the legal profession so lawyers are going to be teaching the window installers the right way to install the windows because they're not working and nothing nothing changes practice than getting your butt sued so we need more attorneys oh wow i never thought i'd heard you say that [Laughter] john let's go to 328 i want to talk basements for a minute and just you know foundations basements in this case we're talking about a basement here joe it's a great detail i like the way this was is put together here um maybe you could just talk a little bit about basement construction and some of the key points here i want you to know that all i did was take a 2 000 plus year old roman method and added color to it and new materials so the big thing is collect the water that hits your roof and direct it away from your building what you don't want is you don't want surface water and rain water to become groundwater so the strategy number one is try to limit the amount of surface water that becomes groundwater i mean slope the ground away drain your roof away from your building and put a impermeable layer a cap right at the grade to try to make it as difficult as possible for the water to get into the ground that's strategy number one strategy number two is assume that you have completely totally failed strategy one it's right if you wanted to do everything you freaking can and strategy two is assume that it didn't work then what you want is you want the water to drain vertically downward faster than it can go horizontally so you want a free draining layer the aromas use rocks without fines and you collect that water at the bottom with a perimeter drain and the drain should be on the outside not on the freaking inside on the outside and it should be lowered than the floor inside that's it it's the roman water management strategy good and you know people argue with me about this all the freaking time and that's all right fine we're not going to put the free draining stones and so the biggest innovation is that you can actually take a dimple board you know like dorkan's drain mat or whatever and you can compress the you know three feet of stone into a half an inch air space that does in essence the same thing so control surface water and then control hydrostatic pressure by draining the water down to a drain and draining it away now you drain to daylight if you can so gravity works or to drain it to a sump with a pump but the pump runs on something called electricity and guess what when you need it the most yeah you have a storm flowers out so you need a battery so if you're gonna have an electric sump pump which is gonna be electric have a battery and if you don't have a battery i'm going to hunt you down and talk sternly to you hey john it works with the taliban yeah oh yeah stern talking john go to 3 30. yeah i think this is it now you mentioned keep the drain on the outside obviously that's preferred in some cases for whatever reason people don't want to hear that it's maybe difficult to do here's the way you design an interior drain yeah we we do tunnels this way the swiss this is the swiss method of doing a tunnel so you put your drainage on the interior of course the swiss didn't didn't didn't advise the people who did the big dig in boston yeah they were retrofitting the drainage on the interior god i i love boston i mean i you know what can i tell you so yeah if you can't dig up the outside um it may not be economical you can't get at it all kinds of stuff the next best not the best but the next best is you drain it on the interior and put in your own perimeter drain on the interior and we we do this a lot because it's often the only only option the the historic people get you know on the structural engineers well if we have brick and rubble the mortar is going to be deteriorated we don't want the water running through the whatever and i have to explain to them that they don't really understand the material science that's going on the reason that the mortar deteriorates is not because the water running through it because the water running through it is carrying salts with it when you get crystallization you get efflorescence and subfluorescence and it's the evaporation of that water that leaves a salt behind that destroys it so if your drainage layer is a vapor barrier and it's sealed at the top the air space goes to 100 relative humidity which means that you don't have evaporation and therefore you don't have crystallization you still have drainage but you're not damaging your mortar okay all right john let's go to the next detail i think what we were talking about here oh um the interior air control layers joe i just thought this was a an interesting approach and interesting detail here can you tell us just a little bit about this well i in 82 83 84 when i was up in canada you know you had a occult running construction nation it was the the cult of polyethylene where they wanted to wrap everything in a plastic condom and have it an air barrier and vapor barrier and i was going to rot and so i said why don't we have a drywall condom as opposed to a plastic polyethylene condom so i turn the interior drywall into the air control layer by simply gluing it so the red lines are caulking and sealant that turn the drywall into the air control layer and that was my became my master's distribution my first real big contribution to the industry which was the airtight drywall approach now having the air barrier on the inside of the framing is not as good as having it on the outside but having a rigid air barrier on the inside that's a semi vapor permeable is better than having a plastic sheet that's completely vapor closed so this is an improvement over poly but it's not as good as putting you know your your air control on the outside in the form of your gypsum board with paint on it or huber zip and covering that with continuous insulation or having an inch and a half of dow styrofoam taped and all of the air barriers approaches on the outside way better than any of the air barriers approaches on the inside this one was better than paulie but not as good as everything else john go to 343 if you would this is another indoor air control layer i just thought i want to point out a little a little different detail here joe well this is uh basically a section of what you just saw yeah this is the airtight drywall approach so i'm basically sealing the ceiling drywall with caulking to the top plate sealing the bottom flip drywall to the bottom plate sealing at the rim joist and then you know so basically i'm turning the interior lining into the air control layer connecting the ceiling drywall to the concrete foundation um i like to do this now on the outside but in 82 83 i wasn't smart enough to put it on the outside i was young yes 26 years old jesus you know joe how much is that catching on the exterior insulation i mean i see it not as much as i would like but i do see it it's it's the future it's all over the code now the 2021. you're not going to be able to build without having a continuous installation layer on the outside or go you know password house with a double wall um yeah the days of single studs with no insulation on the outside or oh it's gone gone baby gone not happening not if you're actually serious about you know gee we're gonna be net zero by 20 30 20 50 20 never i don't know every every week i hear a new a new a new goal but i'm saying none of that is possible without doubling your thermal resistance but that also um increases the air tightness and makes source control more important i wish you could talk a little bit about the source control of interior moisture but also other issues well i i became famous for saying dilution is not the solution to indoor pollution have you not heard that joe absolutely i read it again dilution is not the solution to indoor pollution um source control is the only way to go and uh the problem if you're trying to increase dilution um with warm air change that kills you in the summertime and hot humid and mixed human climates because you're bringing in humidity and moisture is a contaminant and um i'll let you in a little secret um in the old days air conditioners were dehumidifiers yeah but they only demidified when they were running i know that's why i'm a genius they were they're only dehumidified when they were running well what have we done to the runtime of the air conditioning system we've dramatically reduced it well why because we're an ultra energy efficient we've got compact fluorescent lights we've got led lighting we've got windows that have an shgc of 0.2 for gosh sakes we got insulation in our wall i mean it's like and now they don't run and so let's bring in more air what is that yeah yeah you need a dehumidifier and so i mean i ashrae 62 2 hates me because i tell them that they're over ventilating i said build tight over ventilate right so i'm saying you got to you have to have a dehumidifier and so uh you get excessively humid in the south in the winter up north you get excessively dry so you need a humidifier so i'm telling people you know here's you know i'm calling up warren buffett and george soros said i'm saying here's some dehumidifiers and now that we maintained the humidity you need an erv an energy recovery ventilator so they're saying well you need an erv in the south and uh hrv in the north and i'm saying not anymore we're ventilating at such a high rate up north you need to retain the humidity so eurovi's everywhere humidifier demeter fires yay invest and send me and buy me a drink after you get your you know your your stock bonuses i i hear you john but you know even here i'm i'm in climate zone five i'm up in the mountains of uh of pennsylvania here i've got to run a dehumidifier pretty much you know not year round but starting in april until probably october well yeah and let's bring in more air yeah that's going to make it work well we need the air because we have too many contaminants in the building don't build out of stinky smelly disgusting stuff don't fill your house with smelly disgusting stinky stuff and don't do smelly disgusting stinky things in your house i know i i'm a legend you've made a lot of money pointing out the obvious over the years i was i was taught by legends and and i um unfortunately most of them have passed they adopted the young snotty bratty nose kid and and tried to keep him out of trouble and and and i i tried to do the same with youngsters now myself it's called paying it forward because of how they looked after me and the old old ones basically said source control for the building ventilation only for people so you ventilate for the odors generated by people and everything else is source control there's a famous saying that one of the guys that taught me was david hill who you might remember he said that people are evaporatively cooled unvented combustion appliances and that we burn a hydrocarbon fuel called food and we generate carbon dioxide and water vapor and odors and where do we vent i don't sometimes we backdraft those odors and and whatever i need to be handled and the person that figured out how much we actually need it was a guy the name of yagalu for harvard in the 1930s and basically somewhere between 5 and 10 cfm per person to handle odors and that is the ventilation rate that we should have for people and then everything else should be source control and uh well believe it or not um that was taught to me 82 83 84 and we still don't get it i mean you know now with covid they're talking about doubling the ventilation rate and increasing the interior humidity man i'm never going to be able to retire [Laughter] john let's go to the roundup [Music] the roundup is brought to you by april air providing healthy humidity ventilation and air purity solutions for new and existing homes april air healthy air healthy home at aprilaire.com looks like we're going to make april air a very successful business joe they're actually nice people too i mean it's nice to have a company that does good stuff that's also the people in it are are nice i struggle sometimes where i don't like the people but i like the product so you know i just suck it up you know suck it up and use that product cliff let me turn it over to you final thoughts final questions oh just a final comment uh thank joe thank you for for joining us there's another great show uh and memorable and you are a legend uh one update uh healthy buildings 2021's been moved to january 18 through 20 2022. still in honolulu right yeah it's still why but the government wouldn't allow an event that size so it's just been moved back a little yep good stuff um joe before we go final thoughts uh by the way for the listeners i we just scratched the surface of the book here i tried to get through some of the key points in the first three chapters i didn't even get to touch on hvac although joe you brought it in real nicely with some of the discussion about you know how little it runs anymore any final thoughts for our listeners yeah don't don't let the covet stuff freak you out there'll be some good coming out of it so for example i really believe that um four or five air changes per hour in a room with air that's filtered with the merv 13 your mirror 14 filter is a smart plate you can get rid of the nasty stuff with filtration without having to bring in a whole bunch of outside air all right so we can do that we can do that now the concern that i have is you know people are going to crank up to humidity and a lot of the buildings are not going to be able to take it and so my advice is do the lesson that we learned with the commercial buildings 25 30 years ago where we controlled the interior humidity based on outside temperature so when the outside temperature drops below 20 degrees for example we reduce the interior humidity accordingly based on what the building itself can handle so we don't simply say it's going to be 45 relative humidity all winter it might be 45 relative humidity for half of the winter the other half of the winter we're going to control it based on the outside temperature and i think that's going to be the way that we're going to be able to not destroy our buildings while we're dealing with the humidificate with the humidity and everything else so that's my message now um i've not been invited to share this with anybody summary camp next year april or august 1st 2nd and 3rd i'm going to share this with 500 people over beer and barbecue and you're going to be our cult you'll be the cultists to tell people if you don't over ventilate don't over humidify but over filter great stuff joe thanks again for joining us we always appreciate it and uh hope all is well up your neck of the woods and looking forward to next year's summer camp two thumbs up guys thank you all right thank you joe steve brooke for joining us dr joe thanks to our guest this week also to the z man cliff zlatnick for his help as always to john you got to have faith at the controls most importantly our growing group of loyal listeners hey next week we got paula shank on we're going to talk about from the university of connecticut we're going to talk a little bit more about kovid so please come back and join us next friday at noon for the next episode of iaq radio plus for iaq radio i'm spike reel saying thanks for listening [Music] two [Music]

Channel: IAQ Radio

Views: 8,872

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Id: pWYjwZq_1Ao

Length: 67min 22sec (4042 seconds)

Published: Fri Sep 10 2021