Wall Systems

Cavity Wall: Concrete Block Veneer/Reinforced Concrete Block

This versatile and durable wall is the most economical masonry cavity system.

Cavity  Wall:  Concrete Block Veneer/Reinforced  Concrete Block
Truss attachment to bulb 'T', coping and bond beam Ladder type reinforcement Flashing at base of wall

Recommended Building Types

Benefits

Special Considerations

Definition and Assumptions

Backup: Lightweight plain gray concrete block (CMU), 8" x 8" x 16" (nom.)

Reinforcement: #6 vertical reinforcement at 32" on center. 9-gauge joint reinforcement at 16" o.c. (every other course)

Veneer: Lightweight plain face gray concrete block veneer (CMU), 8" x 4" x 16" (nom.)

Cavity: 3" air space

Insulation: 2" rigid expanded polystyrene in drainage cavity

Reinforcement: 9-gauge joint reinforcement at 16" o.c. (every other course)

Flashing: base flashing and weeps

Veneer ties: double side rod tri-rod joint reinforcement @ 16" o.c.

Mortar: Type N, Portland cement/lime, plain gray

Joints: concave tooled

Regional Variations

Fire Rating (hours)

Ungrouted Assembly: 4 hrs

Fully grouted Assembly: 4 hrs

Sound Transmission Class (dB)

Ungrouted: 52.0

Grouted 32": 54.4

Fully grouted: 59.6

STC=(weight of wall)0.223x21.5

Wall Weight (lb/sq. ft.)

Ungrouted: 53 lb/sq. ft

Grouted 32": 64 lb/sq. ft

Fully grouted: 97 lb/sq. ft

Energy Rating

R-value: 12.46 using 2" expanded polystyrene insulation (see note below)

Calculation:

Outside Air =0.17
4 inch CMU =1.19
Air Gap =0.97
2 inch Polystyrene =8.00
8 inch CMU 105 pcf, grouted at 32" o.c. =1.45
Interior Air =0.68
Total =12.46

R-value: 14.46 using 2" extruded polystyrene insulation (see note below)

Calculation:

Outside Air =0.17
4 inch CMU =1.19
Air Gap =0.97
2 inch Polystyrene =10.00
8 inch CMU 105 pcf, grouted at 32" o.c. =1.45
Interior Air =0.68
Total =14.46

Note: The type of rigid insulation you install affects the wall’s insulating capacity (the R-value). Polyisocyanurate insulation gives you 8.0 R per inch (12.0 R for 1.5" or R16 for 2"). Expanded polystyrene insulation is worth 4.0 R per inch (6.0 R for 1.5" or 8 R for 2"). Extruded polystyrene yields 5.0 R per inch (7.5 R for 1.5" or 10 R for 2"). Use either thicker insulation or more expensive polyisocyanurate to achieve a higher energy rating.

Green/LEED Rating

Design Tips

Construction Tips