Replies

1. 
   Eric_M._Borgman | Jun 27, 2001 07:49pm | #1

   *
   Ray,

   Yes, yes, yes, no.

   Eric

1. 
   David_Thomas | Jun 28, 2001 01:52am | #2

   *Specify entrained air in the concrete. Tell them it's for outdoor use - they should know what to give you. By added a bit of air to the mix, it gives the freezing water a place to expand and the concrete does not get as damaged during each freezing cycle.Do you get frost heaves? Does the ground fluff up each winter only to get recompacted as you walk on it in the spring? If you have moisture, fine-grained soils, and freezing temperatures, you can have frost heaves. Overexcavating any fine-grained (silts and clays) soils and replacing with "NFS" (non-frost susceptible) materials would be great but an expense. Trying to keep the underlaying soils dry by sloping the pad to drain the rain would be a cheap step that would help some. With my water line 11 feet deep and only mineral soils under my slab, -David

1. 
   piffin_ | Jun 28, 2001 02:54am | #3

   *I lived in the Rockies for ten years and can't think of a place where the frost line is less than 48".To have a floating slab you need drainage to remove water from under it or it will literally float and heave. Clays will hold water 'till it freezes. Gravel will let it drain. Yes to all questions.

2. 
   Ray_Stokes | Jun 28, 2001 02:54am | #4

   *
   I am having a broom finished, 4" concrete patio poured under my deck. As money permits, we would like to use the pad as a mortar base for flagstones. We live in the Colorado mountains and are subject to 30" frost depth. The soil is mostly settled clay/granite. We plan to slope the pad 1/4" per foot. Should the soil be compacted before a 4" gravel bed is laid; is wire mesh necessary; should expansion joint material be installed next to the house; should any drain lines be put in? Comments appreciated!