Architectural Aspects of Structural Masonry March 13, 2018
Masonry Institute of St. Louis 1
Architectural Aspects of Structural Masonry
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Masonry Structural
Coalition
Presentation Outline…
Structural Masonry Options
Energy Conservation
Moisture Resistance
3D Modeling and Budgeting
Wrap-up & Questions
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Structural Masonry Options
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Maximizing masonry
reduces steel tonnage
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…using masonry for the
building’s structural support
• Bearing walls
• Shear walls • Central Cores
• Hybrid Masonry
What is Structural Masonry?
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Following the Load Path…
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Bearing Wall
Shear Wall
Architectural Aspects of Structural Masonry March 13, 2018
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CROSS BEARING WALLS
PLAN
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Load Bearing Wall Layout Options…
PLAN
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Load Bearing Wall Layout Options…
CROSS BEARING WALLS
LONGITUDUNAL BEARING WALLS
PLAN
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Load Bearing Wall Layout Options…
STRUCTURAL CORES
PLAN
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Load Bearing Wall Layout Options…
Elevator towers
Stair towers
Provides shear, worker safety
Tightens up overall job tolerances
More durable than stud shafts
CMU = “leave behind” forms
Structural Cores…
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Finite Element Analysis
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Structural Cores…
Architectural Aspects of Structural Masonry March 13, 2018
Masonry Institute of St. Louis 3
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Finite Element Analysis…
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Finite Element Analysis…
Hybrid Masonry…
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Other Structural Masonry Options…
CMU Lintels Prefabrication
Foundations
Prefabricated CMU Walls
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Energy Conservation
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Architectural Aspects of Structural Masonry March 13, 2018
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Brick Veneer
1 in. Air Space
Rigid Insulation
Flexible Copper Flashing
Weeps
Loadbearing CMU
Adjustable Anchor
Insulated Masonry Cavity Wall
Premier Wall 19
R-Value is the resistance
to heat flow
HEAT heat
HEAT heat
Thermal mass, or the heat
storage ability of the wall,
is not considered in the R-Value
A material that absorbs heat from a heat
source, and then releases it slowly
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Thermal Mass Materials
How Thermal Mass Works
6:00 am – 3:00 pm
interior conditioned air
3:00 pm – 9:00 pm
radiate heat / cool
Energy codes recognize the energy value from thermal mass
(6-hr thermal lag)
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3AM 6AM 9AM 12PM 3PM 6PM 9PM 12AM
HEAT
LOSSES
HEAT
GAINS
2-HR LAG
6-HR LAG
DA
MP
ING
Source: National Concrete Masonry Association
Thermal Lag
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Interior Thermal Mass
Absorbs excess heat from internal loads
• People
• Lights
• Equipment
mass
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Steel Stud 24” o/c Batt Insulation
Also openings, steel perimeter beams, edge of slabs
Effective R-Value (Thermal Bridging) Face Brick
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Architectural Aspects of Structural Masonry March 13, 2018
Masonry Institute of St. Louis 5
Effective R-Value (Thermal Bridging)
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Prescriptive Methods • “R-Value” Table (c.i. required)
• “U-Factor” Table (Assembly, thermal mass, single wythe CMU)
• Both can be assisted by COMcheck
Total Building Performance • More robust and project specific
(consultant?)
• Software: EnergyPlus, DOE-2
IECC COMPLIANCE OPTIONS
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Whole Building
Analysis… Univ. of
Louisville
Above Grade Wall Insulation
R Value Diminishing Returns
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Energy Savings and Payback in Typical Middle School* *Louisville, KY – other climates similar EUI – Energy Use Index (kBtu/SF)
Roof
Base R = 22 pitched, R 26.3 flat
%EUI Reduction from 132
Simple Payback (years)
R = 29.4 pitched, R
33.3 flat BUR 0.3% 160
R = 37.0 pitched, R
40 flat BUR 0.6% 189
Walls
Base R = 9.1 4” brick, 8” CMU
%EUI Reduction from 132
Simple Payback (years)
R = 13.3” 4” brick, 8” CMU
0.3% <1.0
R = 25, 4” brick, 8” CMU
0.6% 75.3
ICF R = 22, 4” brick
0.5% 335
BVSS R = R37 , 4” brick, 6 “ Steel
Stud
0.6%
Potential
lower initial
cost**
Windows
Base U = .54/.64 glass/frame
%EUI reduction from 132
Simple Payback (years)
Higher U=.67/.69 0.0%
Lower initial cost
Lower U=.23/.31 0.2% 39
Air Barriers
Base 0.5 Air change /hour
%EUI Reduction from 132
Simple Payback (years)
0.2 Air change/hour 0.7% 52
0.1 Air change/hour -0.1%
No return
For more details See: “Cost Effective Energy Efficient School Design” Report (McGinley 2011)
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Boilers
Base 80% %EUI Reduction from 132
Simple Payback (years)
90% 6.5% 0.2
Set backs
Base 64 and 80
%EUI Reduction from 132
Simple Payback (years)
Increase set backs to 55
and 90 18.7% No cost
HVAC Systems
Base VAV Chiller Boiler
%EUI reduction from 132
Simple Payback (years)
Water Source HP 69.8% 23.2
Ground Source HP 71.6% 22.8
HVAC Shut off
Run HVAC at Min Settings
%EUI Reduction from 132
Simple Payback (years)
Turn off HVAC fans/pump 7pm -6am except as needed for set
back temp
21.1% 2.8
Combination Conventional
Base – see report %EUI reduction from 132
Simple Payback (years)
Conventional VAV All- R 13 walls, Set backs Orientation,
Controls, etc.
58.5% 2.5
For more details See: “Cost Effective Energy Efficient School Design” Report (McGinley 2011)
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Architectural Aspects of Structural Masonry March 13, 2018
Masonry Institute of St. Louis 6
Hi-R CMU
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LEED
Up to 52 LEED points possible with masonry
Required Points
Certified: 40 to 49 Silver: 50 to 59 Gold: 60 to 79
Platinum: 80+
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New in 2012…
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Moisture Resistance
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Brick Veneer
1 in. Air Space
Rigid Insulation
Flexible Copper Flashing
Weeps
Loadbearing CMU
Adjustable Anchor
Insulated Masonry Cavity Wall
Premier Wall 35
Dew Point Analysis – CMU
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Architectural Aspects of Structural Masonry March 13, 2018
Masonry Institute of St. Louis 7
Dew Point Analysis – CMU
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Light Gage Steel Stud
Brick Veneer
2 in. Air Space
Building Wrap
Batt Insulation
Flexible Copper Flashing
Weeps
6”Light Gage Steel Studs 16 in. o/c
5/8 in. Dens-Glass Gold 5/8 in. Interior Drywall
6 mil. Vapor Barrier
Adjustable Anchor
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Dew Point Analysis – Steel Stud
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Dew Point Analysis – Steel Stud
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3D Modeling & Budgeting
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Masonry Model Collaboration
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Architectural Aspects of Structural Masonry March 13, 2018
Masonry Institute of St. Louis 8
Masonry Model Collaboration
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Masonry Model Collaboration
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Budgetary Collaboration
Real-time market budget numbers
Alternate comparisons
• Masonry to masonry
• Masonry to other systems
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Life Cycle Cost Reports
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www.bimformasonry.org
Free Revit
Guide
Free Masonry Unit Database
Free Revit
Tools
N E W !
Low Cost Powerful Revit Plugin
by
Relative Cost Study…
2016 using R. S. Means Concrete and Masonry Cost Data
Union wage data
Installing contractor prices
Adjusted for St. Louis, MO
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Architectural Aspects of Structural Masonry March 13, 2018
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Loadbearing CMU vs…
Precast Concrete
Tilt-Up Concrete
Relative Cost Study…
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Loadbearing CMU &
Brick Veneer vs…
• Steel Stud & Brick Veneer
Relative Cost Study…
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Relative Cost - Loadbearing CMU
Single Wythe CMU (20’ tall x 25’ long wall)
• 8” Normal weight, mortar, joint reinforcement, tooled one side $10.03/SF • #5 vertical bars 32” o/c $ 0.75/SF
$10.78/SF • Top course bond beam $14.63/LF x 25 Ft ÷ 500 SF $ 0.73/SF • Vertical control joint $3.95/LF x 20 Ft ÷ 500 SF $ 0.16/SF
$11.67/SF
Source: 2016 Means Concrete and Masonry Cost Data 51
Relative Cost - Precast Concrete
Precast Concrete Wall Panels • 8’ x 16’ x 4” Thick (load bearing?)
• Smooth gray finish
• Includes crane use, low rise
• 50 mile delivery $31.56/SF
• Additions & Options - Exposed aggregate finish $0.77/SF
- Embedded thin brick $10.43/SF
- Granite faced, domestic $33.09/SF
Source: 2016 Means Concrete and Masonry Cost Data 52
Relative Cost - Tilt-Up Concrete
Tilt-up Concrete Wall Panels
• 5 ½” Panels cast on the building slab
$13.01/SF
• 7 ½” Panels cast on the building slab
$14.80/SF
• Reinforced, broom finish
Additions & Options
- Embedded thin brick $11.37/SF Source: 2016 Means Concrete and Masonry Cost Data 53
CMU - Tilt-Up - Precast Summary
Head to Head Comparison
• 8” CMU $11.67/SF
• Precast Concrete $31.56/SF
• 5 ½”Tilt-Up Concrete $13.01/SF
Floor Slab Considerations (Tilt-up)
• Floor slab MEP obstructions
• 6” slab vs. 4” thick building slab
Source: 2016 Means Concrete and Masonry Cost Data 54
Architectural Aspects of Structural Masonry March 13, 2018
Masonry Institute of St. Louis 10
Floor Slab Comparison (Tilt-Up)
Concrete slab on grade, light industrial, reinforced
• 4” thick $6.23/SF
• 6” thick $7.60/SF
• Difference +$1.37/SF
For a 100’ x 200’ x 20’ tall building
• 20,000 SF x $1.37/SF = +$27,400
• ÷ 12,000 SF = Equivalent Wall $ = +$2.28/SF Source: 2016 Means Concrete and Masonry Cost Data 55
After Footings In Place
CMU & Tilt-Up Scheduling
CMU finished CMU started
Tilt panel up
Cure tilt panel
Pour tilt panel
Cure slab
Pour slab
Prepare subgrade
CMU Can Exceed Tilt-Up Schedules 56
Masonry work can begin as soon as footings/foundations are installed
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Scheduling With Masonry...
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Scheduling With Masonry... Reduced Lead / Fabrication Time with Masonry
Brick Veneer
1 in. Air Space
Rigid Insulation
Flexible Copper Flashing
Weeps
Loadbearing CMU
Adjustable Anchor
CMU Back-up vs. Steel Stud
Premier Wall 59
Light Gage Steel Stud
Brick Veneer
2 in. Air Space
Building Wrap
Batt Insulation
Flexible Copper Flashing
Weeps
6”Light Gage Steel Studs 16 in. o/c
5/8 in. Dens-Glass Gold 5/8 in. Interior Drywall
6 mil. Vapor Barrier
Adjustable Anchor
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Architectural Aspects of Structural Masonry March 13, 2018
Masonry Institute of St. Louis 11
CMU Back-Up…
Source: Masonry Institute of Michigan
15 ft. High x 30 ft. Long Wall Section
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Steel Stud Back-Up…
Source: Masonry Institute of Michigan
15 ft. High x 30 ft. Long Wall Section
Additional Concrete
Additional Steel
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CMU Vs. Steel Stud Back-Up
CMU: Total Cost $36.00/SF
Steel Stud: Total Cost $39.92/SF
Difference + $ 3.92/SF
Other Considerations (discussed earlier)
• Effective R Values
• Dew Point Analysis
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Presentation Outline…
Structural Masonry Options
Energy Conservation
Moisture Resistance
3D Modeling and Budgeting
Wrap-up & Questions
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Thanks for the Invite!