This question is kind of a follow-up to the one asked here: how-should-i-add-flooring-in-my-crawl-space. My crawlspace is exactly as the one described.

Basically my house is on a slope and have a very high (8-12ft) unsealed crawlspace. I would like to build a more even and level floor over the vapor barrier, like a deck, so that I can use the space more comfortably (e.g. storage, exercise room?, etc...). I have already added lighting. I don't have any intention of finishing or sealing or insulating or putting up walls. I just want some kind of floor, which will be a short distance (inches if possible) off the ground at the top of the slope and at most at about two cinder-blocks off the ground at the bottom of the slope (I will need a stair or two).

The question is, what's the easiest way to support this floor? Do I really need to dig down and cement in some posts or could I just level out concrete blocks or something without digging in? Obviously aesthetics won't really matter, but it needs to hold some weight and I don't want it to fall over on me either.

In case it matters, I live in the SE USA so rarely experience freezing temps (i.e. no real frost line considerations to worry about), and I have built fences and pergolas before but never a deck.

EDIT: Adding more info as per comments. First some pictures - this is two-year old construction. Blocks until up to ground level, then it is framed. The "window" is actually a blurry vent. In the center of the crawlspace are a couple of the pillars seen in the second picture. I actually probably won't have to touch those by just building the floor across the rectangular 11' x 16' section that goes from the back wall to the first pillar.

Wall Support

The slope drops about 10 inches over 11 feet (i.e. 0.076) and is conveniently quite level across the back wall (i.e. the longer wall) so I only need to deal with slope in one dimension instead of two.

In two years, other than a small amount of water trickling in after extremely heavy rains (i.e. blowing sideways rain), it has stayed completely dry. I have checked this regularly to be sure.

  • Good morning Jason, A few questions, 1 What is the angle of slope under the house? 2. Does water run under during rains? Are there rivulet patterns 3. What type of pier and post system do you have? (Pic?) Without these factors included in your description It is impossible to give a firm answer. Please answer these so we as a community can answer correctly.☺ – David Moritz Jul 23 '17 at 16:21
  • i would coat with gravel, tamp, and lay blocks. if you need concrete later, you'll have the aggregate handy. – dandavis Jul 24 '17 at 4:34

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