GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Zone 6a crawlspace questions

Tia M | Posted in General Questions on

Hello all! I live in South Dakota (6a) and it’s time to decide how I’m going to air my crawlspace. I reciently bought a 1953 house with a full basement. A addition was added on to make the kitchen larger sometime in the past, so there is a tiny dirt floor crawl space that made that part of the kitchen really cold & drafty.

*Only 13.5′ by 7′ and maybe 4′ high. It is built on top of the ground. No mechanicals at all. No water issues. a tiny bit of mold.  Its access is from the yard underneath a porch and its door is almost like a kitchen cabinet door made from plywood. it has one exterior vent that is screwed closed.*

It had its three cement block exterior walls insulated with r10 foam board, the poured concrete wall it shared with the basement was uninsulated. The rim joist had fiberglass. The poly sheet had been run up over the board insulation but had fallen off due to duct tape having let go of the boards and it was just poorly put together. After taking it all apart to inspect the block walls I have rebuilt it to be better. I threw away the fiber glass. airsealed and added foam board to the rim joist, ran new poly over the dirt and up the walls, then insulated walls to R15. I need to build or buy a better door and insulate it. and I need to decide on how to handle air. What I’ve read tells me my options are either 1: run a dehumidifer forever. 2: install hvac suppy/return. 3: run a electric exhaust fan to the outside and open a vent into the house. I dont like any of those options but I think that’s the only 3 choices I have?

*Which option is best for my cold climate?
*Which option is cheapest for my electric bill?
*also I’m sure there has to be a article here about building proper exterior doors for the crawl? Haven’t found it yet. What is it called?
*should I lay foam board insulation on the ground too? I will not be pouring concrete over dirt for a floor. 

Thank you for your assistance!!!

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. Tia M | | #1

    adding in that I airsealed the vent and used foamboard & greatstuff to totally render it null & void.

  2. GBA Editor
    Brian Pontolilo | | #2

    Hi Trina.

    The the crawlspace floor on grade (at the same level as the ground outside) so that the entire crawlspace is above grade, with the kitchen floor 4 ft off the ground?

    1. Tia M | | #3

      yes, yes it is!

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |