Detailing Stem Wall and Vertical Insulation
This is a two part question aesthetic/functional question for slab on grade construction.
Question 1: We have drawn a typical section showing the R10 under the slab and as required, insulation between the slab and stemwall (attached). My building official recommended replacing the 4″ of vertical R10 with a PT 2×6 to use as a nailer for carpet (we are not installing carpet). My builder said he chamfers the edge. I’m concerned that that chamfered edge this will break. We are going polished/sealed concrete floors and do not want R10 or a 2×6 showing.
问题2：垂直绝缘。我更愿意在Stemwall的外面有这个，但我住在树林里，感觉这会填满虫子，如果上面就会受到损坏。有任何想法吗？
Thanks, Chris
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答复
克里斯，
Your detail shows a few inches of the interior of the concrete stemwall showing between the slab and framing above. Is that how your walls will be, or is that just an drafting error?
它还示出了跨越阀杆壁的整个宽度的壁板，这可能是8“。是吗？
我不是在努力迂腐。您提问的答案取决于您所吸引的哪些准确或不准确。
谢谢回复。Stemwall为6“厚。6”最大垂直内墙在典型部分中显示为可选。我的思想是将此降低到0“所以修剪与地板齐平。
克里斯，
If the slab is flush with the top of the foundation everything becomes much easier. Either taper the insulation as you have shown - and I wouldn't worry about the edge being fragile if it's tapered on that angle - or reduce the thickness of the top 6" of the stem-wall t0 cover the full thickness of the insulation.
If you decide to go the second route, check with your inspector first. Some codes want full bearing f0r the plate, some only require a certain minimum width. The two most common ways to reduce the thickness are to attach a 2"x6" to the inside of the concrete form, or taper the outside of the form by using a cant-strip.
However you choose to detail it, leave yourself some wiggle-room to make sure the slab edge is covered. The chances of your foundation wall and the framing above aligning exactly are pretty low.
If the optional 6 inches isn’t a drafting error on the stem wall like Malcom asked, what would be the advantages and disadvantage ?
Why not run 1/2 the insulation to the top of the stem wall as it will be covered by drywall and base trim? That would give you at least R5 insulation everywhere and not expose any insulation.
Carl, where are you finding R5 in 1/2" hard board insulation? Don't want polyiso as a sponge at foundation.
1” of Insulation will give you the R5 and be covered by drywall, base trim and shoe mounding.
嗨克里斯，
Here is what I ended going with for my slab on grade design with stem wall since I wanted to avoid having foam on the exterior.
阿诺德
为什么杆墙在板上上方显示出来？这将是额外的无色外墙。如果即使用板坯保持墙顶，框架墙壁也与墙壁的内部框架，那么1/2干墙和3/4“的装饰和鞋成型将覆盖至少一英寸（或更多）任何将在板坯和杆壁之间暴露的绝缘。
我记得在这个困境中。美学与性能。
I came across this issue with a slab, I ended up lowered the edge insulation to 2" below the top of slab. And I had a poly sheeting going up the wall for radon, so the slab wouldn't adhere to the stem wall, and as it shrunk and left a ½"- ¾" gap off the wall, I filled that with spray foam.
所以不像泡沫的2英寸那样伟大，但在室内装饰进去后看起来很好看。
杰米
You also DO NOT want to use 6" of "gravel" as the base for the concrete slab. It should be compacted 3/4" minus AB which is a sand and 3/4" or smaller rock mix. Compacted with a machine. That provides the best base for a concrete floor. Otherwise you could have problems with just large gravel and no sand/fines as it would not compact properly.
彼得，
我始终明白，透明砾石的圆形砾石（绝缘层下方）的目的是提供一种毛细管断裂，从而使储量堆积在储存到绝缘体中。我同意机器压实，但是您可以为使用AB - 超过3/4进行混凝土次级的使用提供参考吗？比任何事情更好奇。
彼得，
3/4“清除压碎是自我压实的，尽管它是辅助整合的一些振动的效果。随着凯尔说，顶部敷料0f碎石在那里充当毛细血管突破，虽然在你的气候中可能不是很重要
Poly应该在板坯下方，以上保温。