HomeMy WebLinkAboutEngineer's Foundation Recommendations - Supplement 08.06.2015Engineering, Inc.
C I' V 1 L/G13O1t C L IN ICA L
August 6, 2015
Clinton Omang
262 Wooden Deer Rd.
Carbondale, CO, 81623
email: clintandsue().gnai Isom
Dear Clint:
RE: Foundation Recommendations
Garage Addition - Supplement
Lot 20, Wooden Deer Subdivision
262 Wooden Deer Road
Garfield County, Colorado
Project No. 15-30
This letter is a supplement to the Foundation Recommendations Report for the proposed
Garage Addition at 262 Wooden Deer Road, Garfield County, Colorado, dated August 3, 2015.
In the previous report, we specified a structural material consisting of minus 3 -inch road base and
proof rolling for quality control. From our telephone conversation today, we understand that you
already have purchase minus 1 -1/2 -inch road base, due to cost, and will be using it as structural
fill with the triaxial geogrid under the footings, and would like to use the on-site soil for
structural material with the specified layers of triaxial geogrid, under the slab on grade area.
FOUNDATION - The overexcavation within the proposed foundation, will be backfilled,
in 8 inches loose level lifts, and compacted to 100% of the maximum dry density and within 2
percent of the optimum moisture content as determined in a laboratory from a Standard Proctor
test (ASTM D-698). The layers of triaxial geogrid will be as previously recommended.
SLAB ON GRADE - The subgrade under the slab on grade will be overexcavated and
backfilled with the on-site soil or other suitable material approved by the engineer and compacted
to a minimum of 95 percent of the maximum standard Proctor density (ASTM D-698). The
layers of triaxial geogrid will be as previously recommended. Suitable material should be free
from topsoil, organics and rock fragments greater than 3 inches.
The concrete slab should be constructed over a 4 -inch layer of clean gravel consisting of -
3/4 inch gravel with at least 50% retained on the No. 4 sieve and less than 3 percent passing the
No. 200 sieve. The concrete slab -on -grade should be reinforced and control joints scored
according to the American Concrete Institute requirements and per the recommendations of the
designer to reduce damage due to shrinkage. The concrete slab should be separated from the
foundation walls and columns with expansion joints to allow for independent movement without
causing damage.
The structural fill layers must be tested by a qualified professional.
There is no other warranty either expressed or implied.
Sincerely,
LKP Engineering, Inc.
Luiza Petrovska, PE
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P.O. Box 724, Eagle, CO 81631 Tel (970) 926-9088 www.lkpengineering.conn