Presentation is loading. Please wait.

Presentation is loading. Please wait.

Standardized Load Tables Characterizing Residential Solar Thermal and Solar Electric Installations For Residential Structures in Minnesota Jason S. Hanlon,

Similar presentations


Presentation on theme: "Standardized Load Tables Characterizing Residential Solar Thermal and Solar Electric Installations For Residential Structures in Minnesota Jason S. Hanlon,"— Presentation transcript:

1 Standardized Load Tables Characterizing Residential Solar Thermal and Solar Electric Installations For Residential Structures in Minnesota Jason S. Hanlon, PE, MLSE Braun Intertec Corporation September 30, 2013

2 Overview  Establishing Analysis/Review Criteria  Research and Analysis  Pre-Manufactured Trusses  Roof Rafters  Rafter Tables

3 Establishing Analysis/Review Criteria  Closely match IRC content  Consider conditions common to MN  Consider Types of Roof Mounted Solar Technologies

4 Establishing Analysis/Review Criteria  Closely match IRC content  Spans presented try to closely match that shown in IRC Tables  Wood Species  Roof Pitches

5 Establishing Analysis/Review Criteria  Closely match IRC content  Consider conditions common to MN  Wood Species --- Old Doug-Fir  Design Loading Criteria »Based on 2007 MSBC, 2006 IRC/IBC and ASCE 7-05 »Wind Load Exposure B, C, and D  Dead Weight »One Layer ½-inch OSB/Plywood or ¾-inch plank board »One layer asphalt shingles

6 Establishing Analysis/Review Criteria  Closely match IRC content  Consider conditions common to MN  Consider Types of Roof Mounted Solar Technologies  Photovoltaic Panels supplementing electrical services  Solar Thermal Panels supplementing heating services

7 Research and Analysis  Pre-Manufactured Wood Trusses  Challenges  Things to consider  Roof Rafters

8 Research and Analysis – Pre-Manufactured Wood Trusses  Challenges  Common design layout hard to define  Wood trusses are “efficiently” designed. »Controlling component will be the nailer plates

9 Research and Analysis – Pre-Manufactured Wood Trusses  What to consider  Common design throughout the industry: »Top Chord DL = 7 psf »Bottom Chord DL = 10 psf  Changes in Code prescribed Snow Load

10 Research and Analysis – Pre-Manufactured Wood Trusses 1998-Previous MSBC2003-Current MSBC

11 - Roof snow load decreased by 5 psf - Roof snow load increased by 5 psf - Roof snow load increased by 12 psf - Roof snow load increased by 2 psf Research and Analysis – Pre-Manufactured Wood Trusses Summary of Design Load Adjustments

12 Research and Analysis – Roof Rafters (Hand-Framed Construction)  Framing Conditions  Snow Loading  Wind Loading  Material Selfweight  Allowable Stress Design

13 Research and Analysis – Roof Rafters (Hand-Framed Construction)  Framing Conditions  Use of Ridge Nailer Plate (not a ridge beam)  Outward thrust is resolved at exterior wall bearing

14 Research and Analysis – Roof Rafters (Hand-Framed Construction)

15  Framing Conditions  Use of Ridge Nailer Plate (not a ridge beam)  Outward thrust is resolved at exterior wall bearing  Allowable stress values taken from NDS (National Design Standard) for Wood Construction and Historical Douglas Fir Use Book

16 Research and Analysis – Roof Rafters (Hand-Framed Construction)  Framing Conditions  Snow Loading  Exposure Rating B, C and D  Design for Snow Drifting not required per IRC  Limit installation angle of panel so drifting is limited to design depth of snow »Tables presented for different lengths between PV and Solar Panels

17 Research and Analysis – Roof Rafters (Hand-Framed Construction) Table 1 - Maximum Allowable PV Panel Installation Angle Ground Snow Load = 50 psf, Flat Roof Snow Load = 35 psf Maximum Allowable PV Panel Installation Angle (deg) Roof Pitch PV Panel Length (in) 3:124:125:127:129:1212: Note: dash indicates that the solar panel may be installed at any angle up to 45 degrees from horizontal

18 Research and Analysis – Roof Rafters (Hand-Framed Construction)  Framing Conditions  Snow Loading  Wind Loading  Structures 30-ft. or less in height (average)  Not located near isolated hills or ridges or other abrupt changes in topography  Followed ASCE Slight changes in ASCE 7-10 (decrease)

19 Research and Analysis – Roof Rafters (Hand-Framed Construction)  Framing Conditions  Snow Loading  Wind Loading  Material Selfweight  Member DL based on wood species, size, and spacing

20 Research and Analysis – Roof Rafters (Hand-Framed Construction)  Framing Conditions  Snow Loading  Wind Loading  Material Selfweight  Allowable Stress Design  Shear  Bending/Compression  Deflection

21 Rafter Tables  Info needed to determine which table to use  Wood Species  Grade of Wood  Spacing  Ground Snow Design Requirement  Exposure Classification

22 Rafter Tables  Info needed to determine which table to use

23 Rafter Tables  Info needed to use the table  Rafter Pitch  Rafter Size  Projected Rafter Span

24 Rafter Tables

25

26

27  Reinforced Rafter Tables  Similar Analysis approach  Uses a sistered 2x4 member of equal or greater species and grade  Installed as follows:

28 Rafter Tables

29 Questions???


Download ppt "Standardized Load Tables Characterizing Residential Solar Thermal and Solar Electric Installations For Residential Structures in Minnesota Jason S. Hanlon,"

Similar presentations


Ads by Google