1. Comparative Performance of
Residential Walls
J. Gregg Borchelt, PE
Brick Industry Association
borchelt@bia.org

2. Two Properties Important to
Communities and Home Owners
 Fire Resistance
 Missile Impact

3. Wall Systems
 Typical residential construction
 Brick veneer
 Fiber-cement siding
 Vinyl siding

4. Brick Veneer Wall Section
2x4 Top Plate
½ inch Gypsum Wallboard
3½ inch Fiberglass Insulation
Weather Resistant Barrier
½ inch OSB Sheathing
Veneer Anchor
1 inch Air Space
Brick Veneer
2x4 Wood Studs at 16 inches
o.c.
2x4 Bottom Plate

5. Siding Wall Section
2x4 Top Plate
½ inch Gypsum Wallboard
3½ inch Fiberglass Insulation
Weather Resistant Barrier
½ inch OSB Sheathing
Fiber-cement or Vinyl Siding
2x4 Wood Studs at 16 inches
o.c.
2x4 Bottom Plate

6. Fire Resistance
Objectives
 Compare performance of typical
residential walls with respect to fire
resistance rating
 Verify 1 hour rating of assembly with
new “hollow” brick

7. Fire Resistance
 Brick itself has a fire resistance based
on amount of “equivalent thickness”
 Volume of material divided by face area
 Thickness that remains when brick is
squeezed to close any openings, without
reducing face area
 Determined from ASTM C 67 tests; net
area of bed surface
 Used by building codes to establish fire
resistance of brick as a component

8. Fire Resistance
 Solid Brick: Equivalent thickness of
2.7 inches for 1 hour
 Hollow Brick: Equivalent thickness of
2.3 inches for 1 hour
 Wanted to evaluate performance of
wall system built with brick that did
not have a 1 hour rating itself

9. Brick Background
 All brick comply with C 652, Hollow
Brick
 Void area or face shell thickness
 Brick 1 and 2 are from commercial
production
 Brick 3 was made to verify code limit
 Minimum thickness in building codes
 2 inches in Residential Code
 2 5/8 inches in Building Code

10. Brick Tested
Brick 1 Brick 2 Brick 3
3½ inch wide 2¾ inch wide 1¾ inch wide
66% solid 69% solid 83% solid
1 hour rating less than 1 hour not permitted by code

11. Other Sidings Tested
 Typical products, purchased at
building supply firm
 Fiber-cement
 8 inch high by 5/16 inch thick lap siding
 Vinyl
 Premium grade
 Thicker material
 Insulation included
 Nailing schedule complied with
Residential Building Code

12. Fire Test
 ASTM E 119, Standard Test Method for Fire
Tests of Building Construction and Material
 Specimen at least 100 square feet
 9 feet high by 12 feet wide
 Vertical load applied to wood frame, equal to
typical 2 story home
 Required temperature rise in furnace
 Fire exposed to exterior of wall assembly
 Brick veneer
 Siding

13. Fire Test
 Failure Criteria
 Collapse of wall
 No passage of flame or hot gases to
ignite cotton waste of cool side
 Temperature rise of 250 ºF on cold side
 Water penetrates wall under hose stream

14. Furnace

15. Hose

16. Wall Specimen, Brick 1

17. Brick 1
 Test stopped after 1 hour
 No damage to brickwork
 Embrittlement of building paper
 4952.26 scf of natural gas burned

18. Brick 1, Hose Stream Test

19. Brick 2
 Test stopped after 1 hour
 Minimal damage to wall
 Crack at top
 Embrittlement of building paper
 Natural gas consumption not
measured

20. Brick 2, Hose Stream Test

21. Brick 3
 Test stopped at 1 hour
 Cracking in wall
 Building paper burned; OSB charred
 5061.41 scf of natural gas burned

22. Brick 3, After Fire Exposure

23. Fiber-cement
 Furnace turned off
at 22 minutes; relit
at 37 minutes
 Load-induced
failure and flaming
to unexposed face
at less than 1 hour
Flames
breached
cold face

24. Fiber-cement
 70% of fiber-cement siding detached
 Building paper and OSB consumed
 Damage to wood framing
 No hose stream test
 2572.41 scf of natural gas burned

25. Fiber-cement Siding, After Fire
Exposure
Exposed
Face

26. Vinyl Siding
 Furnace shut off
after 2 minutes;
never relit
 Load-induced
failure and flaming
to unexposed face
at 18 minutes
Loading jacks

27. Vinyl Siding
 Vinyl siding, fiberglass insulation and
OSB consumed
 Severe damage to wood framing
 No hose stream test
 858.45 scf of natural gas burned

28. Vinyl Siding, After Fire Exposure

29. Key Results
 All brick veneer walls achieved 1 hour
rating
 Fiber-cement and vinyl siding walls
did not make 1 hour rating
 Vinyl siding and its insulation contributed
to intensity of fire
 Difference in amount of gas burned in
the tests

30. Conclusions
 Brick veneer provides improved fire
resistance over other sidings
 Building codes require a 1 hour fire
rating when buildings are closer than 5
feet
 Homes at risk from wild fires, grass fires,
etc.

31. Benefits to Communities
 Brick veneer provides improved fire
resistance over other sidings
 Protection of residents from exterior fires
 Longer response time for life safety
 Less damage to homes
 Reduced injury for fire fighters

32. Impact Resistance of Brick Veneer
Structures to Hurricane Debris
 Similar wall construction
 Brick veneer (4 inch nominal solid brick)
 Fiber-cement siding
 Vinyl siding (no insulation in siding)
Tenth Canadian Masonry Symposium

33. Objective
 Determine the resistance of typically
constructed residential brick veneer walls
to hurricane-generated missiles

34. Standards
 Florida Building Code:
Assemblies and materials up to 30 ft (9.1 m )
in height must resist a missile impact of a 9 lb
(40 N) 2 inch x 4 inch (50 mm x 100 mm)
timber travelling at 34 mph(54.7 km/hr)

35. Standards
 ASTM E 1996: Standard Specification
for Performance of Exterior Windows,
Curtain Walls, Doors and Impact
Protective Systems Impacted by
Windborne Debris in Hurricanes
 Standard Protection: 40 N (9 lb) 50 mm x
100 mm (2 inch x 4 inch) timber travelling
at 54.7 km/hr (34 mph)
 Enhanced Protection: 40 N (9 lb) 50 mm x
100 mm (2 inch x 4 inch) timber travelling
at 87.8 km/hr (55 mph)

36. Standards
 ASTM E 1996:
 Failure Criterion:
 No penetration through inside surface of
gypsum wallboard

37. Missile Impact Specimen
4 ft square panel
Wood studs
13 mm OSB
sheathing
Weather-resistant
barrier
Gypsum
Wallboard
Batt insulation
between studs
4 inch face brick with
Type N mortar
22 ga
corrugated
anchors, 1
for each 2
sq. ft.
1 inch air space

38. Air Cannon and Specimen
Sighting Cannon on Wall

39. Brick Veneer, Specimen 1
9 lb 2 inch x 4
inch timber at
34 mph
Exterior Damage: Small vertical crack
Interior Damage: None
Point of Impact

40. Brick Veneer, Specimen 2
9 lb 2 inch
x 4 inch
timber at 55
mph

41. Brick Veneer, Specimen 2
Exterior Damage: 9.5 mm penetration, vertical crack 1 mm
at bottom and hairline at top, hairline horizontal crack
Interior Damage: None
Point of Impact
75-100 mm mortar band
mistakenly put around edges
9 lb 2 inch x 4 inch timber at 55
mph

42. Brick Veneer, Specimen 3
 Anchor
frequency
reduced to
that required
for non-high
wind locations
1 anchor for each 4 sq. ft.

43. Brick Veneer Specimen 3
9 lb 2
inch x 4
inch
timber at
79 mph

44. Brick Veneer, Specimen 3
Broken Missile
Point of Impact
9 lb 2 inch x 4
inch timber at 79
mph

45. Fiber-cement Siding
9 lb 2 inch x
4 inch timber
at 34 mph

46. Vinyl Siding
9 lb 2 inch x 4
inch timber at 34
mph

47. Results
Material
Perforation
Speed, mph
1/2 in. OSB Sheathing 22
Fiber-cement Siding 25
Vinyl Siding 25
Brick Veneer >79

48. Conclusions
Perforation speed of a 4 in. nominal brick
veneer wall is in excess of 79 mph for a 9 lb
hurricane design missile
Brick veneer meets requirements for high
velocity hurricane zones in the Florida building
code
Brick veneer meets requirements for enhanced
protection of ASTM E 1996

49. Benefits to Communities
 Brick veneer provides:
 Greater than minimum performance
found in building code requirements
 Safety for home and business occupants
 Fire resistance
 Missile impact
 Reduced property damage from fire and
high wind events
 More durable buildings

50. For More Information:
The Brick Industry Association, Southeast
Region
8420 University Executive Park
Suite 800
Charlotte, NC 28262
Phone: 1-800-622-7425
Fax: 704-510-0042
Website: www.gobricksoutheast.com