10 Comments

1. 
   北部建筑|Jul 13, 2022 06:33am|#1

   Hey Josh, nice to see the evolution of this design.

   我知道PT基础对于大多数人来说都是有争议的，您是否使用这种类型的基础系统研究了任何设计可能性。我的父亲在我进入该行业之前，使用经过压力处理过的木材建造了几个建筑物，无论是使用压力处理的木材而已。在我职业生涯的早期，他和我与他们建造了几所房屋。所有的结构似乎仍然是牢固的。有些已有40多年的历史了。

   I've also been toying with the idea of a frost protected shallow foundation system for the concrete-free slab design. Probably more relevant in my climate where our stem walls are 5 feet deep.

   Looking forward to part 2.

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   乔什·塞林格|2022年7月21日下午12:47|#7

   嗨，兰迪，

   We recently had a client that was in a PT wood foundation here in the city of Portland. We went down the path for a little bit in schematic, but ultimately decided against it not because we thought it wasn't a robust foundation (it is allowed in the IRC), but rather it was far enough afield from typical construction that it was a pretty good premium for not just the construction, but also the design (and specifically, the design review at the planning department). We didn't feel like locking horns with all the trades, building departments, inspectors, etc. for this particular project. That being said, I do find the idea fascinating and know there are numerous examples of successful wood foundations that are 100+ years old and going strong. If the right project comes along, we are game to give it a go...

   我很想看到您进一步从这个想法中脱颖而出，并结合了一个受霜保护的浅基础。我想不出任何理由为什么它不起作用。使它实现，让我知道，以便我可以跟随！

   干杯，

   Josh

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   马尔科姆·泰勒（Malcolm Taylor）|Jul 13, 2022 01:02pm|#2

   Josh,

   It looks like a really well thought out detail. I wonder if a couple of small variations might make it simpler?

   如果Y0U没有在茎墙上放入泡沫并放入泡沫，而是将墙壁框架移动到墙壁上，以使墙壁上的墙壁越过墙壁的内部，那将做两件事：

   - Cover the bottom of the exterior wood fibre insulation, meaning you could eliminate the base flashing and mesh protection, except for a small piece necessary for the bottom of the rain-screen gap. This should also make the sills at exterior doors easier to support.

   - Move the sub-slab insulation up so the top was flush with the stem wall, and run it under the cantilevered sill plate. To regain the height you lost, and make installing baseboard trim easier, you might then want to add a second sill plate.

   
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   乔什·塞林格|Jul 21, 2022 01:02pm|#8

   Hi Malcom,

   First off, thanks for the tip that helped us evolve this foundation in the first place. Since then we have further discussed and refined the idea. It's one of the great benefits of this forum.

   您的细节类似于我们早期考虑的细节。我们遇到的问题之一是将盘子转移到内部的问题是，一个人无法超越某个点。具体而言，固定和较小的延伸锚螺栓需要从茎壁的边缘的边缘不少于2英寸。这是根据我们的工程师。我们在PNW中使用6英寸的茎墙，所以这种限制阻碍了。话虽这么说，我意识到该国其他地区使用较厚的茎墙，也许可以进一步移动该盘子（我们也可以做到，但是我们首先要避免碳和混凝土成本）。在不在地震区域的地区，这可能甚至是一个问题。

   我可以看到使用较宽的底板，尤其是因为它将在细节中显示出1.5英寸的胶合板。浮动胶合板板将更多地移到内部。在右完成的地板上，此间隙可能会很好地桥接（例如，浮动工程地板）。

   This all boils down to creativity and modifying the approach to fit the particular circumstance at hand. For one, we have realized that the CCF SOG foundation isn't great on sloped sites due to the amount of gravel that needs to be trucked in to 'fill' the foundation to the correct grade. In these cases, we are exploring conditioned crawls.

   Thanks for the detail and I will continue to mull it around!

   Josh

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   马尔科姆·泰勒（Malcolm Taylor）|Jul 21, 2022 01:14pm|＃10

   Josh,

   我要感谢像您这样的人，迈克·梅内斯（Mike Maines），本·博吉（Ben Bogie）和其他想念并尝试这些创新的集会的人。对于像我这样的风险不利的人来说，能够从更具创造力的方法中受益真是太好了。

3. 
   kbentley57|7月14日，2022年04:13 pm|#3

   Josh,

   Not to nitpick the THERM model, it does show the general behavior, but it's missing a the foundation anchor bolts. Those essentially inject that purple area up into the bottom of the wall / sill plate where the temperature gradient is already very high. I would be curios to see how adding a ~ 1' long 5/8" cylinder of steel in the middle of that curved the isotemperature surfaces change the behavior, assuming you've still got all the inputs and setup mostly ready to go. Maybe it's not all that much?

1. 
   brendanalbano|7月15日，2022年12:10 pm|#4

   它是有效的在地脚螺栓进行二维分析s, given that the heat flows are actually 3d and the anchor bolts are infrequent? Not to say that the anchor bolts don't matter, but I'm not sure that a 2d analysis at the anchor bolts would actually give you a meaningful surface temperature at the interior surface.

1. 
   kbentley57|Jul 15, 2022 02:35pm|#5

   Brendan,

   It's an approximation to be sure, but a 2D model (rectangle) of the diameter of the bolt would show whether or not there was a significant impact "in the plane of the bolt". In the line between anchors, I imagine it would look more like the diagram looks now. What I'm curious about is the 'cold spots' created along the bottom of the wall, and whether or not any of the surfaces near the interior drywall fall below the dew-point of the interior. In his climate zone, it might be unlikely, or not happen often enough to matter.

   In the interior states, where the temperature is more, seasonal, it could have a larger impact.

1. 
   brendanalbano|Jul 15, 2022 03:57pm|#6

   If the 2d model at the bolt does not show any condensation risk at the interior drywall, you can be confident that there isn't a risk.

   But what I'm curious about is that if the 2d model at the bolt does show a condensation risk at the drywall, would that risk still be there if you ran a 3d model? I certainly don't know, and I don't think there is free software available to run a 3d model like that. I'd be surprised if it caused a real-world issue, but again, wild speculation on my part! It'd be interesting to know.

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   乔什·塞林格|Jul 21, 2022 01:08pm|#9

   为了跟进并添加此对话，螺栓未包含在热模型中。我们让Phius为我们做这项工作，他们没有要求提供此信息。我倾向于同意kbentley57的观点，因为我怀疑4'4'的垂直螺栓的影响会带来很大的影响。当然不是房屋的整体能源使用。

   重要的是要注意，该热模型是针对气候区4C进行的。我相信这将适用于所有4及以上的所有区域，但我强烈建议在较冷的气候区域中运行模型，因为我怀疑将需要在茎墙上使用外部绝缘层，以避免在此位置进行冷点和凝结。