HomeMy WebLinkAboutObservation of ExcavationKutner & Assockdes, Ilnc.1 5020 County Road 154
K Geotechnical and Materials Engineers Glenwood Springs, CO 81601
and Environmental Scientists phone: (970) 945-7988
email: kaglenwood@kumarusa.com
www.kumarusa.com
An Employee Owned Company
office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
August 11, 2025
Red House Architecture
Attn: Bruce Barth
815 Blake Avenue
Glenwood Springs, Colorado 81601
bruce(cDredhousearchitecture.com
Project No. 25-7-503
Subject: Observation of Excavation, Proposed Addition, Lot 12, Ranch at Coulter Creek,
1082 Cattle Creek Ridge Road, Garfield County, Colorado
Gentlemen:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on August 5, 2025 to evaluate the soils exposed for foundation support. The
findings of our observations and recommendations for the foundation design are presented in
this report. Hepworth-Pawlak Geotechnical (now Kumar & Associated) previously conducted a
subsoil study for design of foundations at the site and presented the findings in a report dated
August 2, 2006, Project No. 106 676. The current observation was performed in accordance
with our agreement for professional engineering services with Red House Architecture dated
August 4, 2025.
The addition has been designed to be supported on spread footings placed on the natural soils
and sized for the previously recommended allowable bearing pressure of 2,000 psf.
At the time of our visit to the site, the foundation excavation had been cut in one level from
about 3 to 3'/2 feet below the adjacent ground surface. The soils exposed in the bottom of the
excavation consisted of sandy silty clay with gravel and scattered cobbles. There was existing
foundation wall backfill adjacent to the existing building which appeared to be relatively shallow
depth to bottom of the existing foundation. The results of swell -consolidation testing performed
on a sample taken from the site, shown on Figure 1, indicate the soils are slightly to moderately
compressible under conditions of loading and wetting. The laboratory test results are
summarized in Table 1. No free water was encountered in the excavation and the soils were
slightly moist to moist.
The soil conditions exposed in the excavation are consistent with those previously encountered
on the site and suitable for support of spread footings designed for the recommended allowable
bearing pressure of 2,000 psf. Loose disturbed soils should be removed in the footing areas to
expose the undisturbed natural soils. The new foundation should be doweled into the existing
foundation to span the backfill soils. Other recommendations presented in the 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 subsurface exploration at the site. Variations
Red House Architecture
August 11, 2025
Project No. 25-7-503
Page 2
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 contaminants
(MOBC) developing in the future. If the client is concerned about MOBC, then a professional in
this special field of practice should be consulted.
If you have any questions or need further assistance, please call our office.
Sincerely,
Kumar & Associates,
Steven L. Pawlak, P
SLP/kac
Attachments:
Iodation Test Results
Laboratory Test Results
Kumar & Associates, Inc