Legrand VA Trenchduct Flush Floor Feeder System - Manual (Page 3)

6. Work Subsequent to Trenchduct Installation by Other Contractors:
A. Concrete Placement and Curing:
1. Reinforced concrete design shall be in accordance with American Concrete Institute Specifications for Structural
Concrete for Buildings (ACI301-72) and ACI Building Code Requirements for Reinforced Concrete (ACI318-82),
2. Concrete placement shall follow proper and accepted industry practice and be in accordance with ACI Recommended
Practice for Measuring, Mixing, Transporting, and Placing Concrete (ACI304-73).Concrete must be vibrated at all
trenchducts to insure that the concrete completely fills underneath the system. However, it is imperative that the
concrete not be over vibrated. Over vibration causes segregation of material in the concrete mix which, in turn,
leads to weakening of concrete strength.
3. Concrete curing shall follow proper and accepted industry practice and be in accordance with ACI301-72.
B. After the Concrete Pour:
1. Excess moisture should be removed from inside of the trenchduct within 48 hours after the concrete pour. Remove
cover plates where water may have entered the trenchduct and remove all water from the system. Periodically, check
the trench system for water accumulation or condensation. Depending on job site and weather conditions, a cover
plate removed at several locations along each run will help prevent condensation inside the system. If water is left in
the trench system, it may freeze, causing severe damage to the trench and floor slab.
2. When heavy material or equipment loads will be placed on or moved over the trench system, install temporary planking
that will transfer loads to the adjacent concrete.
NOTE: Cover plates, compartment dividers or other trench components that are damaged during construction must
be replaced by others. This will not be the responsibility of Walker.
3. For BVA Bottomless or IBVA Intermittent Bottomless Trench: Place metal void closures under bottom flange(s)
or on top of outside bottom flange of trench side rail assembly and secure to deck and trench side rail by fillet welds
(1/2" [12.7mm] or longer) and/or blind rivets on 24" [610mm] centers.
4. Floor finish contractor shall clean and prepare cover plates prior to final floor covering installation. Use a suction cup
lifter, Walker part #485, to remove cover plates.
For tile floors: The outside trim extrusion is reversed to the tile position and secured in place
(refer to Finishing Notes and Details).
For carpet floors: The trim extrusion shall remain flush.
5. Consult the carpet supplier for recommendations on installing carpet over the trenchducts.
NOTE: Bottomless trench for use only over UL Listed Cellular Metal Raceway or UL Listed Cellular Metal Floor Raceway
Fluted Section Fittings.