Return to the Old House Forum | Post a Follow-Up

 o
Why was cement poured in two layers

Posted by bcarlson78248 (My Page) on
Mon, Aug 11, 14 at 6:17

I am cutting through the basement floor of my 1940 colonial to relocate some of the plumbing and also add a sump pump as part of a bathroom renovation.

When I chipped through the floor I found it had two cement layers. The lowest layer is about 4" of very hard cement and in very good shape. The upper layer, which varies from about 1/2" to 1" is softer cement that seems to have a fairly high sand content. In several areas it is not strongly adhered to the concrete underneath. The height of the closet flange appears to line up with the top layer, so it looks like the both layers may have been poured before the fixtures were installed.

Under the cast iron pipes I also ran into a charcoal black layer of dirt. At first I thought it was discoloration from contact with the pipe, but it seems more like it might have been something to bed in the pipes before pouring concrete. However, I can't figure out what the material is.

Any suggestions about why they used two layers of concrete, and/or would that have been common? Could it have simply been a way to level the floor?
Also, any suggestion about the what the black material would have been under the pipes?

Thanks,

Bruce


Follow-Up Postings:

 o
RE: Why was cement poured in two layers

They added the top layer to level the unfinished basement floor when they added the toilet.


 o
RE: Why was cement poured in two layers

The pipes were laid in cinder fill.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Old House Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here