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5020 County Road 154
Glenwood Springs, CO 81601
phone: (970) 945-7988
fax: (970) 945-8454
email: kaglenwood@kumarusa.com
www.kumarusa.com Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
September 9, 2024
Eric Berhalter
209 Cedar Breaks Road
Rifle, Colorado 81650
bird@awd.cc
Project No. 22-7-278.A
Subject: Observation of Excavation, Proposed Garage, Lot 27, Grass Mesa Ranch, 209
Cedar Breaks Road, Garfield County, Colorado
Eric:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on August 28, 2024 to evaluate the soils exposed for foundation support. The
findings of our observations and recommendations for the foundation design are presented in
this report. We previously conducted a subsoil study for design of foundations at the site and
presented our findings in a report dated August 11, 2022, Project No. 22-7-278.
The proposed garage will be a single-story structure with a slab-on-grade floor. A thickened slab
with turned down edges placed on the natural soils and sized for an allowable bearing pressure
of 2,000 psf was designed for the foundation support.
At the time of our visit to the site, the foundation excavation had been cut in two levels from ½
to 3½ feet below the adjacent ground surface. The soils exposed in the bottom of the excavation
consisted of calcareous silty sand and gravel with scattered cobbles. The results of a gradation
analysis performed on a sample of the exposed soil (minus 1½-inch fraction) obtained from the
site are presented on Figure 1. No free water was encountered in the excavation and the soils
were slightly moist.
The calcareous soils exposed in the excavation are consistent with those previously encountered
on the site and suitable for support of a thickened slab with turned down edges designed for an
allowable bearing pressure of 2,000 psf. Loose and disturbed soils should be removed in the
footing areas and the exposed soils moistened and compacted. Other recommendations
presented in our previous report which are applicable should also be observed.
The recommendations submitted in this letter are based on our observation of the soils exposed
within the foundation excavation and the previous limited subsurface exploration at the site.
Variations in the subsurface conditions below the excavation could increase the risk of
foundation movement. We should be advised of any variations encountered in the excavation
conditions for possible changes to recommendations contained in this letter. Our services do
not include determining the presence, prevention or possibility of mold or other biological
Kumar & Associates