HomeMy WebLinkAboutUnderpinning (piering) Report from Engineer 09.15.2015September 15, 2015
TO: Mr. Brad Hayden
bradphayden@hotmail.com
RE: Underpinning (Piering) Project
0193 Bud's Way
Parachute, CO 81635
Gary R. Reeder, P.E.
Registered Profesionai Engineer
2937 four Corners Drive, Grand Junction, CO 81503
cell: 970/250-9242
e-mail: garyreeder34@gmail.com
The proposed piering plan is enclosed. Fourteen (14) push piers are proposed at the south wall and around
the SE corner, and seven (7) push piers are proposed around the NW corner at the office area, as shown
on the two attached drawings.
A laser -level survey was done by Foundation Repair of Western Colorado (FRIVC) on June 29, 2015.
These elevations are shown on the drawings with the amount of settling in relation to the referenced point
and/or high elevations in the area.
As seen on the drawings the greatest amount of settling along the south wall is 2-3/4" at the large footing
between the east bay and the adjacent bay just to the west. This Targe footing is the low point along the
south wall. Water penetration is the most likely cause of the settlement. The source of the water may be
from the south -side downspout and/or from the north side of the building under the slab, in addition to
normal rainwater that penetrates under the exterior slabs.
The greatest settlement at the west end office area is along the west wall south of the NW corner. This
settlement amounts to one -inch in relation to the high elevation in the offices.
The amount of lift that can be attained will depend upon the reaction of the following:
• Buckling in the metal siding
• Operation of doors
• Operation of windows
• Cracking in the concrete slab
• Cracking in the office area drywall
• Cracking in the concrete footings and stem wal Is
• Pier capacity
• Residential Structural Inspections
• Foundation Design and Piering
0193 Bud's Way
page 2
September 15, 2015
Depending upon the amount of void that is created under the slab due to lifting, it may be anticipated that
PoIyLEVEL foam will need to be injected under the concrete slab to provide proper slab stabilization.
Keep in mind that with underpinning projects such as this, the field conditions encountered during this
piering project may dictate a change in the number of piers and in pier spacing. Unknown subsurface
features and conditions can influence a change of plan. Also, the location of piping and electrical cables
can change actual pier location.
The piers exert a `point' load on footings and/or foundation walls. In certain situations, it is common
practice by FRWC to distribute the Toad over a larger area of concrete by placing short steel beams of
HSS cross-section between the pier bracket and the bottom of the concrete footings or wall. It is not
uncommon to place such steel beams where cracking has occurred in the concrete stem walls and/or
concrete footings. It is my recommendation that short steel beams be installed at Piers #l, #2, #8, and
#I3.
I will be available for consultation during the progress of this project, and 1 will be on-site at least once,
most likely more, during the piering progress. l will be present on-site during the lifting process and
helping with the final Miser -level elevation survey. When the project is successfully completed, I will
certify the project as such by letter and/or e-mail.
Please call me with any questions you may have.
Respectfully submitted,
Gary R`.'lteeder, PE
CO #19404
cc: FRWC
enclosures (2)