Crawlspace drain
I am here in Idaho to help my parents build their house (climate zone 6). Their crawl space will be conditioned. ICF block stem walls, peel-and-stick waterproofing on exterior of stem walls, footings poured into Fast Form foot material, 1.25” crushed drain rock on floor (about 14”+ deep to top of footings, r10 EPS insulation on top of drain rock, vapor barrier over the foam. French drain around exterior of parameter footings. The interior will be broken up by pony wall footings (compacted 3/4” gravel with fines under interior and parameter footings).
我想知道我们是否需要提供任何内部爬网空间排水。如果是这样，建议什么？污水和抽水？将瓷砖在日光下的瓷砖上排出吗？没有什么？
With the configuration described above, what happens if there is a plumbing leak? Or if somehow water seeps under the footings and up into the crawl space?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
Hi Brent.
Sounds like you are doing all of the right things on the foundation walls for this crawlspace. In my experience, interior perimeter footing drains are more the exception than the norm and are either a judgement call based on site conditions (particularly wet sites should have them) or a belt and suspenders approach by cautious builders.
您需要添加室内排水管的穿孔管将不会对新房屋建造的预算产生太大影响，因此，如果您不确定是否需要它，我会说。如果您可以通过立足点和日光运行它，那是一个不需要沥青和泵的不错的选择。
+1 on Brian's post. In addition, you should still consider interior perimeter perforated drain pipe in the crushed stone for use as a radon collection system. Adding the pipe during construction is cheap. If you can run it through the footings to daylight, it will act as a passive radon vent, potentially eliminating the need for an active system. Be aware that if you need to add an active fan in the future, you might have to disconnect the crossovers, so make some allowance for that in the designs. if there's no radon in the local soils, don't worry too much about this.
Also, you mention concern about plumbing leaks and water rising up through the slab. Plumbing leaks will always be an issue, whether you have a drain or not. Put a water alarm on the floor and hope for the best. As far as water rising up, that shouldn't be an issue if the perimeter drains are working. Again, draining to daylight is best, if you have the slope for it.
Brent,
可能需要在爬网空间的地板上排出位置。加拿大建筑法规说，H0USE的最低水平必须有地板排水。根据当地法规，此排水管要么与风暴或卫生系统有关。如果太低，则需要一个污水坑和泵。
Running some drain tile around inside the crawl space sounds nice for radon purposes as well as a fall-back safety for water issues. But the crawlspace subfloor is going to be pretty chopped up with various pony-wall footers. See the attached image for an approximation of the foundation. The 3/4 gravel is already compacted. But I supposed I could dig some trenches into it to run drain tile under the interior footings to create a loop around the interior of the foundation. Then I could run it out to daylight under a parameter footing. But if I do that, would I be okay to place the drain tile in a little trench, cover it would a bit of gravel, and just wet it and tamp it down a bit with the end of a shovel handle or something? I don't want to have to rent a compactor for this alteration. And would I be okay just placing drain tile in that way without a sleeve or compression wrapping or anything like that? Should the sections going under the footings be non-perforated tile?
Brent,
What's your plan for the finished crawlspace? Are you pouring a scratch-coat (rat slab)?
当我们把室内pony-walls我们一个立足点lways have a short concrete stem-wall on top, as the level of the finished grade should be at least 6" inches above the level of the top of the footings for moisture control. With a stem-wall, you can run drainage pipes right through them and out the exterior walls to connect with the perimeter drains outside.
在脚下挖掘意味着内部排水管是系统中最低的位置，并且可能在某个时候将水带入爬行空间。
有关完成爬网空间的一些计划，请参见附件图。这看起来可以接受吗？
Brent,
是的，这很有意义。对不起，我对ra系统不了解足够多的帮助。在基础和外围排水管水平以下的水位以下，似乎不是一个好主意。我会尝试寻求避免这种情况的解决方案。
Okay. Fair enough! And you think my plan looks okay without short stem walls for the pony walls?
My concern is the pony walls being at the same level as the top of the footing. It's mitigated somewhat by using a treated bottom plate - probably fine.
我对照片有些困惑。我们认为将是垫子的紧凑型石头，而基础上的基础在上面？如果是这样，您会用足够的石头填充内部装置以覆盖3英寸的管道吗？这将使排水管的放置容易。
If not, I think I would probably skip them, unless radon is a big risk in your area. That close to the mountains, I'm guessing that your soils are pretty free-draining. If so, I would definitely lean towards skipping interior drains. It also looks like your crawl floor is going to be close to grade level. Even less risk of water rising up under your slab.
回答您的问题：内部管道不必包裹在袜子中。如果您期望大量的水流，袜子可以帮助防止其淤塞，但是无论如何您可能不会流动。是的，穿过页脚/茎墙的管道应为实心管道。请注意，它应该经过，而不是在基础/茎壁下。
Yes, the compacted stone that you see in the actual photo is what the footings will be sitting on. The area between the footings will then be filled with the crushed drain rock up even with the top of the footings - so yes, plenty there to cover 3" pipe. But that crushed drain rock also extends down approximate 5"+ below as well. See the attached diagram for a better idea of what I am looking to do. If I put 3" pipe in level with the bottom of the footings, there will be about 6" of drain rock above the pipe, and about 5"+ below the pipe. In that case, would the pipe be very useful? If I were to dig that pipe down lower, it would end up below the grade of the footings.
我与一个工程场所的一个人交谈，该工程已经为这个项目完成了结构性工程，他似乎对管道的想法并不满意。他似乎对它的立足点更加满意。在基础下运行管道会使它接近实际的土壤等级。
Maybe I should just skip the drain pipe. As I recall, I saw something online showing that a lot of Idaho has high risk for radon, but the county where my parent's house will be was more moderate. But I would like something in place in order to reduce any risk from radon. It is just a bit more complicated with all those pony wall footings cutting through the crawlspace floor.
Would one passive radon stack with a pipe up through the roof and teed out for several feet in one of the sections between footings be helpful? In that case, there would not be radon pipes going through footers to all the different sections, but maybe it would reduce the pressure a little under the vapor barrier to help prevent radon getting into the conditioned crawl space and thereby into the house?
另外，关于如何通过小马墙详细说明蒸气/ra屏屏障的任何建议？我当时想将其延伸到地面上，并在其顶部建造小马墙的木材部分。但这意味着它将在小马墙螺栓上有孔。
您可以将VB在泡沫下面而不是在其顶部运行，然后直接穿过小马墙的下方和窗台之间。这也将有助于保持门槛干燥。无论VB在EPS上方还是以下，您都必须使用相对硬的EP进行踏步（和膝盖）流量。我总是喜欢在地板上至少有一块老鼠平板（2英寸）。如果您将平板平滑漂浮，您会在机械师的爬行者上爬行。您不知道这是多么好当您在爬网空间的尽头工作时。
For the interior drains, I would put them at the same level as the exterior drains or even slightly above. You want the exterior drains to do the work. How are the exterior drains draining? Do they drain to daylight, or something else? If not to daylight, then there's no point in connecting the interior and exterior drains. The interior drains can then drain to a sump pit. Get one with a sealed lid if in radon area. The lid itself can be the radon suction point if necessary. I wouldn't worry a bit about running the drains through the pony wall footings. You only need a single pipe around the whole perimeter, and the reinforcement in the footings can go over the pipes and still be in the middle of the footing. Or, you can run the pipes near the top of the footing and run the reinforcement under the pipes, still with plenty of concrete around the reinforcement to do its job. You just don't want the pipes higher than the footing and I wouldn't run them lower either because then they will collect rising water before the exterior drains do.
The exterior drains will drain to daylight. But I am thinking I like the idea of doing a separate drainpipe circuit on the interior that runs into a sealed sump pit. We could do one with no pump in it or exit pipes attached and just have it there in case it is ever needed for water or radon. Does that make sense?
是的，这一直都这样做。将内部管道围绕周围的内部管道放在没有污水泵或ra管的密封坑中，这是一种常见的治疗方法。这项工作在施工期间相对便宜，之后非常昂贵。如果您需要一个，则以后安装泵或ra管相对容易。