HomeMy WebLinkAboutObservation of Excavation 10.08.24K+nh'#fi:k, rii,vi.*"
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5020 County Road 154
Glenwood Springs, CO 81601
phone: (970) S45-7988
fax; {970) 945"8454
ernail: kaglenwoocl@kilmarusa.conl
An fmploya* 0wn6d Compcny www'kumarusa'com
Office Locaiierns: Denver (HQ), Parker, Coiorado $prings, Fort Collins, Gienwood $prings, and Sumrnit Counly, Coiorado
October 8,2024
TE Builders
Attn: Thad Eschelman
7380 County Road 100
Carbondale, Colorado 81 623
tb ad (ri-ite]tu i I d enJ sI
Subject:
Project No. 24-7-581
Observation of Excavation, Existing Log House, 3 10 Flying Fish Road, Garfield
County, Colorado
Dear Thad:
As requestecl, a representative of Kurnar & Associates observed the excavation at the subject site
on October 1,2024 t<l evaluate the soils exposed for foundation support. The findings of our
observations ancl recommendations fbr the foundal.ion supporl are pl'esellted in this report. "fhe
ser,rices were perfbrrned in accordance with our agreement fbr prol'essional engineeriug services
to TE lluilders dated October 1,2A24.
The existing resitlence is a one story log home over a crawlspace. A new Spread footing and
stem rvall fbundation is proposed to sttppott the existing house
At the tine of our visit tg the site, we observed tha.t the original fourrdation supporls consisted
of l8-inch cliarneter concrete piers about 4 feet long.. The area under the house ancl around the
piers had been excavated out. The foundation excavation had been cut in otre level fiorn 3 tcr
4 fbet below the adjacont exterior ground surfacc. The soils exposed in the bottom of the
excavation consisted of relatively dense, slightly silty, sarrdy gravel with cobbles.
Corrsiclering the conditions exposecl in tlte excavation and the nature of the proposed
construction, spread fbotings placed on the undisturbed natural gravel soil designed 1br an
allowable soil bearing pressure of 2,500 psf can be used fbr supporl o{'the existing log house'
Footings sliould be a minirnurn width of 16 inches lbr continuous rvalls ancl 2 f'eet for columns.
L,oose ancl disturbed soils and existirig fill in footing areas slrould be removed and the bearing
level extencled clown to the undisturbed uatural soils. Exterior footings should be provided with
adequate soil cover above their bearing elevations for litst protectiotl. Continuous fbundation
walls should be reinfcrrced top and bottom to span local anomalies such as by assuming an
unsuppeirted length of:at least l0 feet. Foundation walls acting as retaining structures should
also tre designed to resist a lateral eafth pressure bilsed on an equivnlent fluid unit weight of at
least 4li pcf for on-site soil as backfill, There is no point in installing a perimeter drain, as there
is rro way to <Jrain the excaverticxr and the soils are not nroisture sensitive. Tlie hottorn of the
floor joists could be sealed with plastic sheeting to retlucc thc potential of moisture fi'ont the
existing grounclwatcr fi'om cntering the huilding. lSackfill placed aroutrd the structure should
be compactecl ancl the surfuce gracled to prevent porrding within at least l0 f'eet o{'the building'
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TE Builders
October 8,2024
Page2
The recommendations submitted in this letter are based on our observation of the soils exposed
within the foundation excavation 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 may be greater than indicated in this report because of possible
variations in the subsurface conditions. [n 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,
l{nrnrnr' & Associates,
Daniel E. Hardin, P.
DEH/kac
Kumar & Associates, lnc. @ Project No. 24"7-881