HomeMy WebLinkAboutEngineer's Letter 01.21.2019KURTZ & ASSOCIATES, Inc. Structural C9nsultants
5012 County Road 154 Phone + Fax. (970) 945-6305
Glenwood Springs, Co. 81601
MEMORANDUM
1'O: GARFIELD COUNTY BUILDING DEPARTMENT Jan. 21, 2019
ATTN: Andrew Schwaller
COPY: Terrie Trofholz
RE Structural Assessement: Existing Buildings,
251 County Road 237,
Garfield County Colorado
performed a structural inspection of two adjacent garage/shop structures at the
noted property. The two buildings are contiguous: the two buildings have a
common wall and are constructed with a series of door openings which face a
paved auto court on the south side of the buildings.
The original building holds two overhead garage doors and a single man door,
and measures, in plan, 52'-0" east -to -west by 38'-0" north -to -south. I will refer
to this as the east building. Constructed as an addition on the west side of the
original, east building, the west building measures, in plan, 23'-0" east -to -west
by 50'-6" north -to -south. The south wall of the west building houses a single
man door and a single overhead garage door. The south walls of the two
buildings align. I understand that the buildings were constructed in 2003.
The buildings are founded on cast in place concrete foundations with continuous
perimeter foundation walls and footings. The interior concrete slab on ground
floors of both buildings are in excellent condition: the slabs are free of heave or
settlement, and are free of surface spalling and cracking. At the original east
building the floor slab was poured over the perimeter concrete stem wall. The
size and depth of the concrete stem wall and footing at this building was not
determined. At the west building the stem wall extends approximately 9" above
the interior floor slab, and the top of the continuous perimeter footing is 1'-11"
below the top of the interior floor slab. Given the existing site grading, it is
possible to raise the exterior grade on the west side of the existing building so
as to increase the frost depth. A storage shed has been constructed on the
north end of the west building. At the south end of the west building (i.e. at the
auto court) the frost depth to the bottom of the existing footing is approximately
2'-6".
2
The two buildings appear to be in good condition: no signs of differential
movement or distress were noted. The existing foundation systems appear to be
adequate to safely support the building dead Toads and design live Toads.
The roof of the 52 foot wide east building is framed as two bays. Each of the two
bays houses an overhead garage door at its south end, and the two bays are
separated by a center glue laminated (glu-lam) beam which runs north to south
(i.e. front to back) of the building. In each bay premanufactured wood roof
trusses spaced at 24" on center span east to west from the center beam line to
the respective exterior bearing wall. The east and west walls of the east building
are constructed as continuous wood stud bearing walls. The walls do not have
openings. The center glu-tam beam measures 8.3/4" x 24" deep and spans 38
feet north -to -south. The glu-lam beam is supported at the north and south
exterior wall of the building and by a center post. The center post is a 6.3/4" x
12" glu-lam post with a custom bolted steel cap plate and bolted steel brackets
at its base. The roof framing system and bearing walls are in good condition
and are structurally adequate to safely support dead loads plus a design snow
load of 40 PSF.
The wind load resisting system of the east building consists of the continuous
perimeter stud walls on the north, east and west sides of the building. From a
design perspective, the wind Toad resisting system is a three sided shear wall
system. Given the fact that the three walls are continuous and uninterrupted by
openings, this shear wall system is structurally adequate to resist ultimate
design wind speeds of 115 MPH.
The structural framing system of the west building is a slightly modified standard,
premanufactured steel building. The steel building is constructed with three
steel frames: A frame at the north and south exterior walls, respectively, and a
mid -length frame. The frames span east to west and are each constructed with
wide flange beams and columns. The beams are W14 x 22's and the columns
are W8 x 21's. The roof rafters are 8" deep steel 2' shapes spaced at 4'-O" on
center and spanning 25 feet north to south. Wall construction at the north and
west exterior walls is standard construction for premanufactured steel buildings
with 8" horizontal wall girts spanning between steel columns. The north wall and
the north bay of the roof are 'X' braced to resist wind loads. The steel building's
framing and bracing systems are structurally adequate to safely resist a design
snow load of 40 PSF plus building dead loads and ultimate design wind speeds
of 115 MPH.
have reviewed copies of the proposed apartment which is to occupy the north
half of the west building. The apartment will be, in plan approximately 24 feet
deep (north to south) by 22 feet wide. The apartment is to be a two level unit
with an interior loft floor, and an interior stair. At the time of my inspection the
loft floor was partially constructed. I have also reviewed a materials list for the
3
framing material that the contractor has ordered to complete construction of the
loft floor. As 1 understand it, 9.1/2" BCI/6000 floor joists spaced at 16" on center
will span north the south in two bays: The BCI's will span from the north exterior
wall of the west building to a center beam line, and from the center beam line to
the a edge beam at the south end of the loft. The interior stair is to be
constructed in the south bay of the two bays. As I understand it, each beam is to
be a triple 1.3/4" x 16" LVL (Laminated Veneer Lumber) beam. This framing
system is, in general, structurally appropriate.
Kurtz and Associates, Inc.
Brian Kurtz, P.E.
D9 joiCe.4"
18744