Date |
Text |
2007-01-23 16:30:10 | ****CORRECTIONS**** |
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| SAMANTHA HILL, BUILDING PLANS EXAMINER |
| 561-805-6724 [email protected] |
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| FBCFLORIDA BUILDING CODE 2004 |
| FBC RFLORIDA BUILDING CODE 2004 RESIDENTIAL |
| FBC EBFLORIDA BUILDING CODE 2004 EXISTING BUILDING |
| CODE |
| FBC*CITY OF WEST PALM BEACH AMENDMENTS TO THE |
| FBC2004 |
| |
| 1.)PLEASE SEE PREVIOUS LISTS IN REGARDS TO USING WALL |
| PRESSURES FOR THE SOFFIT.ALSO NOTE, FROM EMAIL FROM |
| ROBERT BROWN ABO TO JASON HANCHUK, PE, THE FOLLOWING: |
| |
| I HAVE REVIEWED THE EXAMPLE THAT YOU SENT.AS |
| PREVIOUSLY STATED, I AGREE THAT ONE LOAD CASE IS 'WIND |
| PERPENDICULAR TO WALL' AND THAT YOUR METHODOLOGY |
| ADDRESSES THAT LOADCASE.THE WIND LOAD ON THE SOFFIT |
| UNDER THAT LOAD CASE IS A POSITIVE PRESSURE. |
| |
| HOWEVER, WHEN WE SPOKE YESTERDAY AND AGAIN TODAY, AND |
| WHEN I SPOKE TO MR KELAHER, I POINTED OUT THAT THERE IS |
| A CASE AT THE EAST-WEST GRADE LEVEL WALKWAY FROM OLIVE |
| AVENUE TO DIXIE HWY WHERE THERE IS NO WALL (SEE SHEET |
| A-1 OF LOUIS C. KALLINOSIS, AIA PLANS).AS I STATED, |
| IN THAT LOCATION, THE WIND WILL ACCELERATE ACROSS THAT |
| SOFFIT IN THE SAME MANNER THAT IT DOES ACROSS A FLAT |
| ROOF.THAT ACCELERATION WILL RESULT IN NEGATIVE |
| PRESSURES (SUCTION) ON THE SOFFIT IN EXCESS OF THE |
| PROPOSED ZONE 4 WALL PRESSURE STATED IN THE WIND DESIGN |
| LOAD CALCULATIONS.I DO NOT SEE THATYOU OR MR |
| KELAHER HAVE ADDRESSED THAT LOAD CASE. |
| |
| I DISAGREE WITH THE SECOND PARAGRAPH OF YOUR LETTER |
| DATED 1/8/06 (SHOULD BE 2007?) ADDRESSED TO ALLEN |
| PADILLA.IT STATES THAT ZONE 2 AND 3 LOADS ARE |
| OVERHANG LOADS.I WOULD CONTEND THAT FOR A FLAT ROOF |
| THERE IS NO OVERHANG.IF YOU REFER TO FIGURE 6-3 IN |
| ASCE7-02 YOU WILL SEE THAT FOR A FLAT ROOF THERE IS NO |
| OVERHANG FOR ZONE 2 AND 3.ALSO FIGURE 6-11B IN |
| ASCE7-02 WHICH GIVES EXTERNAL PRESSURE COEFFICIENTS FOR |
| GABLE ROOFS WITH SLOPE RANGING FROM 0O (I.E. FLAT) TO |
| 7O, GIVES PRESSURE COEFFICIENTS FOR ZONE 2 AND 3 ON THE |
| ROOF AND THEN GIVES SEPARATE COEFFICIENTS FOR ZONE 2 |
| AND 3 AT THE OVERHANGS.THIS WOULD NOT BE THE CASE IF |
| ZONE 2 AND 3 WERE FOR OVERHANGS ONLY. |
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| WE ALSO NEED TO CONSIDER THE CASE OF 'WIND PARALLEL TO |
| THE WALL'.THIS LOADCASE WILL RESULT IN A NEGATIVE |
| PRESSURES (SUCTION) ON THE SOFFIT IN EXCESS OF THE |
| PROPOSED ZONE 4 WALL PRESSURE STATED IN THE WIND DESIGN |
| LOAD CALCULATIONS. |
| |
| I DO NOT FOR ONE MOMENT CONSIDER DESIGN FOR WIND LOAD |
| TO BE AN EXACT SCIENCE BUT I BELIEVE THE PROPOSED |
| DESIGN TO BE NON-CONSERVATIVE AS THE WORST CASE |
| NEGATIVE PRESSURE LOADCASE DOES NOT APPEAR TO HAVE BEEN |
| FULLY INVESTIGATED.THE FACT THAT THESE REPAIRS ARE |
| EVEN NECESSARY WOULD IMPLY THAT THE SOFFIT ON THIS |
| BUILDING WAS SUBJECTED TO SIGNIFICANT NEGATIVE WIND |
| PRESSURE EVEN DURING THE 'LESS-THAN-DESIGN' WIND |
| EVENT(S) THAT CAUSED THE FAILURE.EITHER PROVIDE |
| JUSTIFICATION FOR THE USE OF ZONE 4 WALL PRESSURES FOR |
| THE CASE AT THE SOFFIT ABOVE THE EAST-WEST WALKWAY AND |
| FOR THE 'WIND PARALLEL TO THE WALL' CASE, OR AMEND THE |
| NEGATIVE PRESSURES IN THE WIND DESIGN LOAD |
| CALCULATIONS. |
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