Foundation Repair? Contracting Soil or Solid Rock in Austin?

[oldtoiletsmkgdflrpots]

Originally Posted by CptnRn

Was he selling something?

No, he just wanted in.

[CptnRn]

Originally Posted by oldtoiletsmkgdflrpots

No, he just wanted in.

A ranch we have often stayed at near Wimberley has several goats running wild on the grounds. They were rather pushy about begging for food when they came around. I remember one that I tried to give a banana, it refused to eat the banana but gobbled up the peel. It too often tried to come into the house/cabin so we had to keep the hook latched on the screen door.

[CptnRn]

Originally Posted by CptnRn

That is not entirely true, while most of the worst areas of expansive soils are East of IH-35, there are pockets of expansive soils West of IH-35. Alandale has some of them and there are probably others. There are also some areas East of IH-35 where the soils are not a problem.

larger map here http://texashistory.unt.edu/ark:/675...m1/1/high_res/

To the O.P. Foundation repair is often needed in many parts of Austin.

Originally Posted by mickey65

So what are we looking at on this map? What colors are good and which are bad??

I'm sure there are better soils maps available today then that 1904 map, but I have not been able to find them online. So working with what I have available I have tried to provide a better explanation of these soil types. I pulled these designations from the legend on the right margin of the map, but have reordered them from best to worst in regard to stability for foundation construction.

The map is dated 1904, I found the soil types that went with it described in this publication dated 1905. Soil survey of the Austin area, Texas, Sequence: 5 | The Portal to Texas History This soil survey was done mostly for identifying agricultural potential but it does tabulate a mechnaical analysis of the soils, breaking down the amount of gravel, sand, silt, clay etc. The higher the silt and clay amounts, the more expansive the soil is, i.e. the worse it can be for foundations, it expands and contracts more with moisture changes.

I assigned stars "*" to each soil type based on how I interpreted the soil types with, "*****", 5 stars being the most stable. As you can see from the map huge areas of Austin, especially North & East Austin, RR, Pflugerville, etc are build on soils with high silt and clay content, which makes them more problematic for foundations. On the positive side they are the best for many kinds of farming.

Legend color - soil initials - soil name - silt%/clay%
white - rock outcrop *****
brown - Tl - Travis gravelly loam - 8-15%/4-45% *****
salmon - Lf - Lufkin fine sandy loam - 14-28%/7-47% ****
pale pink Yl - Yazoo sandy loam - 16-64%/8-19% ****
grey - Cs - Colton stony clay - 33-55%/32-54% ***
orange - Ac - Austin clay - 37-42%/36-44% **
light orange - Ys - Yakima stony clay - 21-26%/45-74% **
light green - Yc - Yazoo clay - 32-40%/41-52% *
light olive - Hg - Houston gravely clay - 32-48%/37-41% *
light grey - Hc - Houston Black Clay - 33-52%/38-45% *


This 1906 map for the areas south of the Austin map uses many of the same soils designations. It does not extend very far West but does include Buda, Kyle & San Marcos.

San Marcos Sheet - Soil map, Texas, San Marcos sheet, Sequence: 1 | The Portal to Texas History