Wood-Framing Methods For Energy Savings

Transcription

1 Wood-Framing Methods For Energy Savings WOODWORKS Charlotte November 2 David Lewis FIELD MARKETING MANAGER Disclaimer: This presentation was developed by a third party and is not funded by WoodWorks or the Softwood Lumber Board.

2 The Wood Products Council is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES), Provider #G516. Credit(s) earned on completion of this course will be reported to AIA CES for AIA members. Certificates of Completion for both AIA members and non-aia members are available upon request. This course is registered with AIA CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

3 Course Description Although the building envelope is commonly focused on when looking at methods of meeting or exceeding energy code requirements, there is much to be gained in optimizing woodframing and associated details for high energy performance. This presentation will review common sense solutions for framing a tight, energy-efficient envelope. Long wall panels, and how they can reduce material and labor costs, while increasing effectiveness of insulation, especially in raised heel trusses, will be reviewed. Other topics covered will include the use of insulated headers, an introduction to buried ducts and other methods of providing energy efficiency while reducing waste, material and labor costs in multi-family and commercial woodframe construction.

4 Learning Objectives 1. Demonstrate methods of meeting and exceeding energy code requirements using wood-frame wall and roof assemblies. 2. Highlight opportunities for increased energy performance in attic spaces through the use of raised heel trusses and long wall panels. 3. Review the role that framing-material selection and specification has on total building energy performance. 4. Discuss methods of improving total building energy use while reducing waste by using techniques such as insulated headers and buried ducts.

5 Outline Manufacturing specifications for Plywood & OSB (Wood Structural Panels ) PS1, PS2 Grade Stamps Exposure explanation Installation guidelines roof, walls & floors Energy efficient framing

6 Nothing Outperforms Wood

7 Plywood or OSB? Used as Intended, Plywood and OSB are Interchangeable

8 Manufacturing Standard PS1 Plywood Only Prescriptive Examples: 23/32 AC AB Marine apawood.org

9 Manufacturing Standard PS2 Performance Based Allows manufacturer to produce sheathing (plywood or OSB) based on deflection, bond durability and dimension tolerances. apawood.org

10 OSB & Plywood Have Strength Axis

11 OSB Lay Up

12 Traditional Panel Stamp Thickness Roof Floor Exposure Rating Mfg. Std s. Mill No.#

13 Newer Panel Stamp Just APA Thickness in inches New Logo Thickness Category

14 Span Rating Conditions Strength axis perpendicular to supports Continuous across 2 or more spans

15 24 Minimum Panel Width at Roof Peak R275A 24 min. apawood.org

16 Exposure Durability Levels Exposure 1 Made to resist normal construction delays PS 2 Waterproof resin (glue) Permits D-grade veneer (plywood) All OSB unless Overlaid Exterior Waterproof resin (glue) Minimum C-grade veneer (plywood) Only OSB with a moisture protective membrane applied during manufacturing will be stamped Exterior For decay resistance select PT plywood

17 Typical Weathering

18 Moisture may affect panels, edge swell, buckling, mold, etc. Although not structural could still be a costly nuisance.

19 Protect From Exposure As Soon As Practical

20 Evaluating Weathered Panels Sheathing and framing need to be close to in-service Moisture Content, 19% or below. Individual panels damaged while saturated should be repaired or replaced. i.e., drywall cart wheel holes. Simply walking the roof or floor sheathing provides a good field test. If its firm it s most likely good. If in doubt - replace it. If panel testing is needed a 4 x4 panel is preferred by the producing mill or APA for testing. It takes many weeks of continuous saturation for decay to start.

21 PS 1 Grades Specifying WSP s 1/2 CDX (C face, D back, exterior glue) 5/8 A-C 3/4 O & ES, oiled and edge sealed, concrete form PS 2, Rated Sheathing 7/16 Rated Sheathing, Exposure 1 19/32 Rated Sheathing, Exterior / Exp 1 23/32 Sturd-I-Floor (T&G or Sq. Edge)

22 Structural One (Struc-1) When do you need Struc 1? Added Shear, approx. 12% over RS Added stiffness It will add approximately $1 to $2 per/sheet and may be less available in your area requiring additional lead time and minimum order Consider stepping up 1/8 thickness for example from ½ to 5/8, or 15/32 to 19/32

23 Fire Retardant Treated Sheathing (FRT) FRT will reduce panel design values Every treating agency has proprietary Tables for the wood they treat. The code is specific, the material must be pressure impregnated or done during the manufacturing process to be FRTW. With the exception of pressure treating, anything applied to lumber or WSP s by a third party after manufacturing is not FRTW.

24 apawood.org

25 Fasteners & Fastening Connections require proper selection and installation of the fastener whether using nails, screws or staples. Table IBC Specify fasteners by Shank Diameter and Length, not 8d, 6d, etc. Ex:.131x 2-1/2 Vs. 8d

26 Fastener Information ESR 1539 (ICC Report) Provides tables for fastener comparison Ex: 8d common vs. 6d common or staples Download for free at

27 Overdriven Fasteners Reduce Shear and Pull Out Capacity

28 Overdriven Fasteners APA Recommendations Prescriptive If equal or less than 20% of fasteners are overdriven by <1/16, then they may be ignored If greater than 20% of fasteners are overdriven by more than 1/16 or any greater than an 1/8, then add 1 additional fastener for every 2 overdriven

29 Nails Spacing is Important

30 Ya Gotta Hit Something

31 Improved Floor Construction Edge swell is number one complaint Consider premium grade sub-floor Dry in ASAP Moderate sanding of joints is the fix Squeaks rank at number two (hardest to fix) Delamination is number three Minor delam (10-12 sq/in) may be OK

32 APA Flooring Tips apawood.org

33 Floor Squeaks Squeaks are caused by movement Movement is caused by poor connections Framing to framing Sheathing to framing Framing to sheathing Framing to metal hangers

34 Apply full beads with minimal globs

35 No more than one or two panels ahead

36 Apply Foot Pressure to Act as a Clamp

37 Unequal Spans Unequal Spacing Soft/Stiff Spots Poor Joist Layout

38 Similar Spans Similar Spacing Consistent Performance Good I-Joist Layout

39 Floors 80 Ft or Longer Need Expansion Joints apawood.org

40 Roof Sheathing *1/8" spacing at all edges APA RATED SHEATHING Panel clip or tongue-and-groove edges if required 1/8 Spacing applies to both OSB & Plywood

41 What can Happen when adequate spacing is not provided

42 Improved Wall Construction

43 Traditional 4x8 wall sheathing

44 Multi Story

45 Why Lap The Floor Framing?

46 (Energy) Efficient Sheathing Choices

47 47 Perfect Sheathing Lengths

48 WindStorm & TallWall Lengths Length Thickness 97-1/8 7/16, 15/ / /16, 15/32, ½, 19/32, 23/ /8 7/16, 15/ / /2 7/ /16, 15/32, ½, 19/32, 23/ /8 7/16, 15/ /4 7/16, 15/ /16 7/ / /8 7/ /8 7/16 Manufacturers Lengths & Thicknesses May Differ

49 Sheathing Options WSP sheathing can be used for combined shear and uplift Reduce or eliminate uplift connectors based on engineering IBC referenced design manuals WFCM, SDPWS and ICC 600 provide this information APA s SR101 is a good reference

50 Combined Shear & Uplift Table

51 Struct. 1 RS (b) Wood Shear Wall Capacity ASD Shear Wall Capacity (plf) Min. Nominal Nail Spacing at Panel Edges, (in.) Panel Nail Wood Structural Panel Thickness (in.) Size (a) /16 or 1/4 6d / /16 8d / /32 10d /16 or 1/ d 3/ / /16 8d / / d 19/ (a) Nail size is given for common or galvanized box nails (b) RS = Rated Sheathing

52 IBC Allows for 40% increase in Shear values PLF, for Wind Design Good Value Engineering Tool 7/16 equal to 15/32 if 16 oc

53 IBC/FBC Allows a 40% Increase for Wind ( and ) so : 260 x 1.4 = 364 vs 240plf Provides additional uplift capacity with combined use (WindStorm/TallWall) framing

54 Advanced Wood Framing PRACTICAL ENERGY SAVINGS OPTIONS

55 Most Eng s Will Not go with Single Top Plate or 2x4 16 o/c in High Wind

56 Source: Information gathered from DOE and the Building Performance Institute by The Home Performance Inspections of North Carolina

57 Caulking/Foaming IECC, You Must Seal Joints

58 Reduce Air Infiltration through Walls

59 Eliminate Joints

60 Tighten the Envelope

61 Blocking Does Not Air Seal

62 Reduces Insulation Performance

63 Reduce Handling, Cut Waste & Build Faster! Old Way Full Height OR 57 pieces 35 pieces

64 NAHB TESTING The NAHB Research Center compared the air leakage between traditionally installed 4x8 panels and walls with tall wall and found air leakage being reduced by up to 60% on wall sections with housewrap, OSB, fiberglass batts and drywall. ENERGY RATER TESTIMONIAL Builders using tall wall OSB wall sheathing I see a significant reduction in air leakage into the home. By minimizing the sheathing joints, we have seen blower door testing on fiberglass batt insulation approach the air leakage rates on homes using spray foam insulation.

65 Proper Flashing Important to Prevent Water Damage and Reduce Air Leakage Use a peel & stick flashing

66 Kick Out Flashing is Critical

67 Simple Solutions for Major Problems

68 AAMA & FMA Installation Standards Written by industry experts including manufacturers, water proofing consultants and contractors. Step by step directions Compatibility of sealants

69 Improve Wall Insulation Performance

70 RAISED HEEL ENERGY TRUSSES For Better Insulation Performance

71 New Design Values in PRN-133 Allows Removal of Hurricane Clips in Most Wind Zones Full height insulation over top plate

72 Design Values for Uplift Load Resistance With Raised Heel Truss 15 ¼ to 24 apawood.org

73 Two Stud Corner Adds Insulation *Depending on wind loads this may not be an option due to overturning hold down.

74 Two Stud Corner To Add Insulation May not be allowed if overturning hold down is needed for wind/seismic loads.

75 2x6 Wood Framing Boosts R-Values, But Does it Reduce Framing Costs? It Depends R-13 to R-15 Cavity Insulation R-19 to R-21 Cavity Insulation 2x6 Wall Framing 2x4 Wall Framing

76 Radiant Barrier Roof Sheathing

77 Buried Ducts are in the 2018 IECC Available for use now

78 New APA Document

79

80 Thanks for Attending Questions? This concludes The American Institute of Architects Continuing Education Systems Course DAVID LEWIS NORBORD