My home has a small 20x30 dirt crawlspace. It currently has a sump pit/pump, 4" perforated pipe going to the sump pit, all covered with gravel. I would like to permananely stop the moisture in this crawlspace and I am considering having a mason pour concrete. Before I begin talking to masons I would like to know as much as possible about the proper way to do this. Some questions I have are:

1) can the plastic be placed over the existing gravel or must the plastic be layed between 2 layers of sand to prevent puncturing?

2) how many inches of concrete is required?

3) must the concrete be poured higher than the footing?

4) should the concrete be pitched toward the sump pit?

5) should I seal the concrete after it is cured?

6) what other questions should I be asking each mason?

Thank you all very much for the feedback. I appreciate the time.


Edited by mjmustang (01/01/10 02:56 PM)