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HEPWORTH-PAWLAK GEOTECHNICAL
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July 26, 2013
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Beck Building Company
Attn: Tim Dee
P.O. Box 4030
Vail, Colorado 81658
(tim( beckbuilcls.com)
Job No. 112 243B
Subject: Observation of Excavation, Proposed Deck Addition, Deevy Residence,
736 Forest Road, Vail, Colorado
Dear Tim:
As requested, a representative of Hepworth-Pawlalc Geotechnical, Inc. observed the
excavation at the subject site on July 24, 2013 to evaluate the soils exposed for foundation
support. The findings of our observations and recommendations for the foundation
design are presented in this report. The services were performed in accordance with our
agreement for professional engineering services to Beck Building Company, dated July
17, 2013.
The proposed deck addition will be supported on 4 column pads(3' by 3') designed for
an allowable soil bearing pressure of 2,000 psf. The deck addition is located on the
northwest corner of the house.
At the time of our visit to the site,the foundation excavation for three of the column pads
had been cut in two levels about 4 to 4%2 feet below the adjacent ground surface. The
excavation for the fourth column pad, located to the east of the other three, was cut about
5 feet below the surrounding ground surface. The soils exposed in the bottom of the
excavations consisted of mostly natural, clayey sand and gravel. The results of a
gradation analysis performed on a sample of the clayey sand and gravel(minus 3 inch
fraction)obtained from the site are presented on Figure 1. Ledge rock was encountered in
the southern part of the larger excavation adjacent to the house. We recommended that
the footing pad in the ledge rock area be doweled into the rock. No free water was
encountered in the excavation and the soils were moist.
On July 25th, we observed 4 dowels consisting of#5 bar drilled 5% inches deep into the
ledge rock and epoxied in place for support of the southwest footing. Two 6-inch
diameter solid PVC pipes were observed coming out of the house under the northwest
corner of the existing footing. The purpose of these pipes is unknown but may have been
part of the original construction dewatering for the house. We recommended that the
Parker 303-841-7119 • Colorado Spring, 719-633-5562 • Sily erthorne 970-46S-1989
Beck Building Company
July 26, 2013
Page 2
pipes be extended out beyond the excavation to drain downslope. We understand that the
northwest corner of the existing house footing will be underpinned down to native
soil/ledge rock.
Considering the conditions exposed in the excavation and the nature of the proposed
construction, spread footings placed on the undisturbed natural soil or ledge rock
designed for an allowable bearing pressure 01 2,000 psf should be adequate for support of
the proposed deck addition. Footings should be a minimum width of 2 feet for columns.
Loose and disturbed soils in footing areas should be removed and the bearing level
extended down to the undisturbed natural soils. Exterior footings should be provided with
adequate soil cover above their bearing elevations for frost protection. Backfill placed
around the structure should be compacted and the surface graded to prevent ponding
within at least 10 feet of the building.
The recommendations submitted in this letter are based on our observation of the soils
exposed within the foundation excavations and do not include subsurface exploration to
evaluate the subsurface conditions within the loaded depth of foundation influence. This
study is based on the assumption that soils beneath the footings have equal or better
support than those exposed. The risk of foundation movement maybe greater than
indicated in this report because of possible variations in the subsurface conditions. In
order to reveal the nature and extent of variations in the subsurface conditions below the
excavation, drilling would be required. It is possible the data obtained by subsurface
exploration could change the 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,
HEPWORTH—PAWLAK GEOTCHNICAL, INC.
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attachments Figure 1 —Gradation Test Results
Job No. 112 243B
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