_本播播系列是由博士博士博士和建筑科学公司博士教授的为“建筑科学基础”课程的为期两天的课程。有关参加现场课程的信息，请访问_buildingscienceseminars.com.
_本周，乔博士谈到绝缘建筑物中的雨水控制;具体来说，砖的影响如何，如何安装它，它是如何安装的，如何安装它，以及为什么。_______________________________

节能建筑的雨水控制

雨控制真的，真的，真的很重要，现在我们将真的，真的，真的，真的很好。真的，真的，真正的良好建筑都会有很多绝缘，因此他们真的真的，真的，真的，真的，真的很低的干燥潜力。因此，雨水是一个非常大的交易。我要从雨控制角度谈论的所有东西都已经知道了很长时间;这只是我们不必知道它。换句话说，我们知道东西，把它写在书中。它已知很长一段时间了。它只是因为干燥的潜力而堕落，我们真的不必擅长它 - 我们只需要足够的。现在我们必须是非常好的。为了展示砖的水阻滞能力，我用了一个普通的花园软管。我已经打开了墙壁的背部，看水在大约25到30秒的时间里穿过砖，所以砖对水透明。现在，这并不总是这样;从水控制的角度来看，砖件的性能明显变化。现在没关系，几乎是因为我们假设砖泄漏，所以我们将水控制层放在它后面，排水平面。我想谈论一点是渗透穿过砖的水机制水实际上没有通过通过砖。水实际上并不能通过砂浆。水从连接处流过之间砂浆和砖，这是欣赏或理解的重要措施。通过砂浆和砖之间的连接的水通常不会发生在上个世纪的最后一半之前，这意味着我们与砖和砂浆相当不错，直到最近，这是因为我们停止让老人做砖。在让砖头浸泡之前让我解释一下砖曾经做过的事情。首先，你必须了解一下砖的制作。砖是在砖窑中制作的。它在窑中有一千点。所以当砖头出砖窑时，它已经成千上万度，真的，真的很干燥。它是窑干。它的水分含量是令人难以置信的低，如零。我们把它从窑中取出，我们用塑料包裹，我们把它发给了就业站点。砖将干燥的可能性是什么？百分之百。 The old timers, 100 years ago, before they would put the brick on the mortar bed, they would dip the brick in a pan of water so that, when they put the brick on the mortar bed, it wouldn’t desiccate the mortar, wouldn’t suck the water out of it. If it sucked the water out of it, there wouldn’t be a bond between the mortar and the brick. That lack of a bond that we get today allows water to pass through. It doesn’t affect the brick structurally; remember, brick is a big deal from a compression perspective. We didn’t really care much about the tensile strength, so we weren’t really caring about that bond. We now call it a setting bed. What that means is that we have an awful lot more water passing through the first layer of brick.一点点水可以真正加起来通过第一层砖的水越过多少水？嗯，大约1％或小于1％。现在似乎看起来很多，但如果那水直接进入大会。如果我们将排水层，排水平面向闪光系统指向排出墙壁的闪光系统，它很容易管理。通过包层穿透水的典型方式是通过瓦片时尚分层焦油纸。我们称之为“排水平面” - 我们希望将“雨在飞机上”。你不需要太多的排水空间我喜欢“排水平面”这个词，因为它描述了这一层的功能——它在一个平面上排水。有时我们称它为WRB，这取决于你与ASHRAE或ASTM委员会交谈，可能意味着“耐候性屏障”或“防水屏障”。我对屏障不感兴趣;我希望进行引流。这就是为什么我喜欢排水平面这个词。我不喜欢障碍。我想要排水。为了使排水发生，你实际上需要在覆层和排水平面之间有一个间隙。如果你把砖压碎，使它与排水平面直接接触，排水就不会发生，因为水会被毛细管力固定在那里。你需要一个间隙。 A traditional gap — and I use the term “traditional” for a reason, because it is based on tradition, go figure — is around 25 mm or 1 in. All you need is about 3/16 in. for drainage; you don’t need an inch. Why and where do we get the inch from? Well, the inch comes from the typical thickness of a mason’s knuckles and fingers. It’s a historical artifact. If attorneys laid brick, it’d be a 1/4 in. Now does that imply that I don’t need an inch for drainage? I’m not implying it at all, I’m说它。我不需要一个1英寸。排水差距。事实上，我根本不需要大部分间隙;3/16在。会给我排水。迫击炮粪便是问题的一部分那么迫击炮粪的大问题是什么？砂浆粪便非常影响排水。但迫击炮粪便影响是通风，我们必须明白，有时我们可能想要透气覆盖并排出包层。因此，它对建筑罩的设计变得重要，以实际决定我们是否想要排出和通风或只是排水。如果您想通风，您需要一个空气入口，空气出口和连接入口和出口的清晰通道。这意味着没有砂浆粪便。因此，砂浆粪便显着影响包层，但它们不会显着影响排水。为什么透气覆盖？如果墙壁包覆可以存放大量水，会发生什么？这将是一个水库。我们会称之为“水库包层”。我们可能会将砖块描述为水库包层，这个水库将在雨季活动期间收取。所以下雨在砖上，砖弄湿了，砖的表面上有很多水。它没有被排水，因为它存储了。就像一块海绵：你用水填满海绵，然后，一旦海绵填充，只有那么如果你添加更多的水，就会排出水分。换句话说，如果你把水加入砖墙，水就不会出来底部;它一直在建立，直到你不能再存储任何水，然后水排出。水库是收费的。 Think of this as a water source. Next, the sun comes out and beats down on the brick. What happens to the temperature of the water in the brick when the sun beats down on it? It gets higher. Now there is hot water on the outside of the wall. So moisture flow is going to go from where? Warm to cold. Think of the water as splitting—some of it is going to evaporate to the outside, and some of it is going to evaporate to the inside. The concentration of water in the brick is greater than the concentration of water in the outside air but also the water in the air在后面砖。水分将从更高的浓度下降到较低的浓度。请记住，我们将遵循热梯度和浓度梯度。一堆水分将最终在砖的背面上升我们想要的是一个移动的空气流拦截，向内驱动的水分并冲出墙壁的顶部。因此，我们希望背包储层覆盖物，以耦合或断开储存器从大会其余部分的覆盖物。每个人都在这里掌握语言吗？耦合，断开，背通风，水库熔覆。这只是我们将使用的语言来描述这些现象。鹅不是蒸汽屏障如果砖背后有砂浆粪便，我们不会获得有效的后通风，水库包层并不与墙壁断开连接。让我们说，WRB（无论是什么）是tyvek。Tyvek是一个梦幻般的塑料Web。它非常擅长处理液相水。它是非常蒸气打开，所以Tyvek不会是蒸汽屏障。事实上它大约有50个烫发。商业Tyvek大约20个烫发;住宅是大约50个烫发。所以我们会说水会通过鹅的蒸汽形式穿过Tyvek，如鹅。让我们说那里有胶合板在墙上鞘。 Is plywood a vapor barrier? No, it’s not. As the moisture is driven in through the Tyvek, it will increase the moisture content of the plywood. The plywood will breathe, and then the moisture will end up where? In the wall cavity. So the more vapor-open the sheathing-building paper complex, the more likely that moisture will blow through that assembly. What if instead of plywood I had Dens-Glass Gold? Let’s say that this is a commercial building. Dens-Glass Gold is probably the single most common commercial sheathing. It’s around 30 perms, so it breathes. So moisture is going to blow through the Tyvek and the Dens-Glass Gold like a hot knife through butter. Is the fiberglass insulation going to stop it? Fiberglass is very, very vapor open. It’s going to be around 150 perms for three inches, so it really breathes. So where is the water going to end up? Well, if there is polyethylene in the wall, it is going to condense on the poly and run down and corrode the metal track or rot the bottom plate. If there isn’t poly in the wall, if it’s gypsum board, it’s going to blow through the gypsum board until it hits the vinyl wallpaper. So a really, really bad scenario would be metal studs with gypsum board on the inside with vinyl wallpaper, with Dens-Glass Gold on the outside, Tyvek, a brick veneer and mortar droppings. We would call that a hotel.错误的决定导致模具和腐烂所以它在砖上下雨，砖弄湿了，太阳穿过整个Darn的事情，你将在乙烯基和石膏板的界面上最终得到很多模具。现在我真的不在乎，因为它被困在乙烯基和石膏板之间。它在墙上，但我没有呼吸它，所以这不是一个问题。但水分将升起并增加，直到我开始在石膏板背面生长模具。现在它在腔中，它不再处于乙烯基和石膏板之间的界面。它实际上是在腔体，在它与玻璃纤维相交的腔侧。再次，如果它留在那里，我没有太多问题。嗯，如果我有一个掉落的上限返回气能，它在负压下，它现在连接到我的外墙，如果你弹出天花板瓦片，那么内部石膏板是密封的可能性是什么？零。你将在一点点矿物羊毛中铲起来吗？是的，给我一个休息，一个糟糕的过滤器。所以我将实际上将模具吸出墙壁并将其注射到占用空间的呼吸区。现在，这将是一个问题。这就像在你的表面上有霉菌，你会带着你的鼻子吮吸它。这是健康效果。这一点是我们通常有一系列事物发生If there weren’t mortar droppings in the wall cavity and the cladding were back-ventilated, there wouldn’t be any inwardly driven moisture, and I could probably (and the operative word here is probably) get away with vinyl wallpaper in places like Chicago. On the other hand, even with no mortar droppings and back-ventilated cladding, I could never get away with the vinyl wallpaper in a place like Atlanta — the operative phrase is “get away with.” If I didn’t have the vinyl wallpaper at all, I could probably not have to worry about too much of an issue with mortar droppings with my brick veneer from a ventilation perspective as long as I had my flashings done right. The liquid water would drain away. I could live with the reservoir because the moisture driven in would actually blow all the way through the assembly and life would be pretty reasonable. So if you have a reservoir cladding, you need drainage. We don’t need much of a gap for drainage, but we need a lot for back ventilation. How much do we need for back ventilation? The answer is: It depends. It depends on what the reservoir is. You could get away with as low as 3 or 4 mm, or 6 mm, or sometimes 9 mm; sometimes you are going to need 25 mm. When you aren’t sure, you basically ask for as much as you can get. It’s a pretty reasonable way of doing things in life: You err on the side of caution.