Earthen floor finish coat

I am doing a new earthen floor over an insulated 8” compacted gravel subfloor, “slab on grade”. I am putting radiant heat tubes in the floor. I am currently about 2” shy of finished floor, with about 1000 square feet of earthen floor to lay down, coming up in about 2 months. Because of the volume of material I need and the thickness of the floor, it seems like a better use of material to use a more coarsely sifted mixture with longer straw fibers for a base coat, then spend more time to create a smooth finish coat.

I have Sukita’s earthen floor book, which only mentions but does not discuss finish coats for floors

Does anyone here have experience with this?

Thanks!

Here is a site with ideas, https://conversations.echocommunity.org/t/sealing-earthen-floors/5244

We did a 3/4 inch thick base coat with masonry sand, bagged clay and finely chopped straw (2" long max) and then a 1/4 inch thick finish coat of just sand and clay. Here's the video of our earthen floor install:

Thanks Aaron! I watched your video and it looks great.

Did you let the base coat fully cure and dry, then wet it before doing the finish coat? Any delamination issues between the coats, now that it has been a while since you finished it?

Super informative video, thanks for taking the time to put it together.

Scott Lawhead wrote:Thanks Aaron! I watched your video and it looks great.

Did you let the base coat fully cure and dry, then wet it before doing the finish coat? Any delamination issues between the coats, now that it has been a while since you finished it?

Super informative video, thanks for taking the time to put it together.

In this case the the base coat was allowed to fully cure and dry because of some timing considerations on the project but I think as soon as the base coat can take your weight I think it would be okay to apply the finish coat. You should allow the floor to fully dry before sealing it which we didn't do and it still seemed to turn out okay.

The floor has been in for about eight months and no issues.