HomeMy WebLinkAboutBLD2007-01435 ENG LTR 4-21-08.TIFApril 21, 2008
S. A. Brown Development Company
8304 Aeromarine Blvd
Catawba, NC 28609
Re: 8304 Aeromarine Blvd
Porch Framing Structural Evaluation
HCEC — 0408073
Dear Scott,
HARRISO
C O N S T R U C T 1 O N &
C O N S U L T I N G E N G I N E E R S
Per your request, Harrison Consulting Engineers has completed an evaluation of the structural
integrity of the framing making up the wrap -around porch installed at the above referenced site.
Site visits were made on April 6, 2008 and again on April 16, 2008 in support of gathering
pertinent data necessary for the evaluation. The evaluation included both the shed roof and the
porch framing with the following recommendation made as a result of the analysis.
Item 1:
The shed roof located on the left side of the house (as seen looking at the front of the house)
spans approximately eight (8') feet off the side of the house. The rafter support beam at the
outward edge of the roof spans approximately twenty (20') feet between columns. The
evaluation considered the required design load condition placed on the long header. Based on
the results of the evaluation, the double (2) 2x12 SP header is acceptable and will support the
required design basis loading.
Item 2:
Along the right side, the shed roof overhangs the cantilever porch. Due to the cantilevered
framing making up the porch, the roof header must be supported on knee braces extending down
to the two (2) wing walls and the two (2) solid CMU columns below. At each of these column
support locations, install an 8x8 PT column extending up from the cantilever porch deck to the
roof rafter header. The column should be notched at both the roof header and the deck header as
shown on the attached drawing. An 8x8 knee brace should then extend down to the concrete
column above the garage and connect to a beam seat as shown.
Item 3:
The porch along the right side cantilevers four (4') feet beyond the support header beam running
front to back between columns. The joists me 2x12 @ 8" on center which extend eight (8') feet
inside the house. Based on this configuration, the evaluation indicates the joists are sufficient to
support the loading as required.
Harrison Construction and Consulting Engineers
Phone(704)280 -1913 Fax (704) 375 -1867
Structural Evaluation
8304 Areomarine Blvd.
Page 2
Item 4:
Also along the front right side the deck joists are not able to span eight (8') feet back into the
house due to plumbing routed just inside the house. In addition, the header beam running front
to back supporting the deck cantilevers out from the wingwall column. To remediate this
unstable condition, the framing should be augmented as follows:
• Add a 2x12 ledger board along the right side of the house at the same elevation of the
cantilevered porch header beam. Extend 2x12 joists @ 16" on center from the cantilever
over to the new house ledger. This joist framing should extend out to the end of the
cantilever porch header.
• Add a second ledger on top of the existing ledger along the front of the house to extend out
beyond the cantilevered porch header and attach to the end of the cantilever porch band. The
cantilever porch band is supported back to the main front right column.
• Install Simpson CS 16 coil straps to wrap around the end of the cantilever porch header and
up to the new doubled 2x12 header extending perpendicular off the comer of the house
which frames into the outside porch band header mentioned in the item above.
This new framing modification will provide the necessary support for the end of the cantilever
porch header beam and also support the porch joists that are not able to extend back into the
house.
I tem 5:
Along the right side porch, the cantilevered porch header beam is currently bolted into the
concrete columns above the garage with two (2) 1/2" concrete anchors. In addition, the
cantilever porch beam is spliced away from the support. To remediate this situation, the
cantilevered porch beam should be reinstalled with the splices occurring at the columns. Each to
the (2) 2x I2 beams framing into the columns should be bolted into the concrete columns with
two (2) 5/8" bolts. This will ensure the splice is at the column and each beam extending out
away from the column has two (2) bolts at the connection.
Item 6:
The remainder of the porch deck was evaluated based on the installed framing configuration,
member sizes and spans. Based on that analysis several recommendations are made are shown
on the attached layout. These modifications occur along the rear and left rear sides of the porch
deck and involve adding additional collector beams to unload several of the installed beams
which are currently overstressed at the required design loading condition. Please see the
attached drawing for the recommended modifications.
Harrison Construction & Consulting Engineers
2244 Colony Rd, Charlotte, NC 28209, Phone (704) 280 -1913
Structural Evaluation
8304 Areomarine Blvd.
Page 3
We appreciate the opportunity to provide you with this assessment. If you should have any
questions, please feel free to call at any time.
Sincerely,
orge A. Harrison, P.E, G.C.
Harrison Construction and Consulting Engineers, P.A.
Harrison Construction & Consulting Engineers
2244 Colony Rd, Charlotte, NC 28209, Phone (704) 280 -1913