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Brian Lloyd

High-lift vs. Low-lift

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The terms ‘high lift’ and ‘low lift’ grouting are not technically defined in the building code, but are used to describe two methods of grouting. In low lift grouting, discrete sections of masonry are constructed in heights not exceeding 5 ft-4 in. Once that height is reached, reinforcement is placed in the wall and then grouted. In high lift grouting, masonry is constructed up to 24 feet high (subject to some limitations) before grout is placed. Each lift of grout can be up to 12 ft-8 in if several conditions are met (such as the masonry having cured for at least four hours, the grout slump is 10 to 11 inches, and there are no intermediate bond beams). Both methods have advantages and disadvantages. These are detailed in NCMA FAQ 06-14 (attached to this post). A review of these advantages and disadvantages will usually help to assist in choosing a method for a given project.

FAQ 06-14 - High vs Low Lift Grouting.pdf

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I am having a heated argument with the G.C. on a project we are supplying the reinforcing on, In the General notes under Concrete Masonry.

FILLED CELLS SHALL BE FILLED WITH 3000 psi GROUT AS PER ACI 530-11 AND ACI 530.1-11. FILLING OF CELLS SHALL BE DONE IN MAX. FOUR FOOT LIFTS WITH A MAXIMUM POUR OF 12 FEET. USE MECHANICAL VIBRATION TO ACHIEVE GROUT FILLED CELLS.

Now our contention is that this would be considered "low lift grouting" and the reinforcing bars would be 4 feet + the required lap, the bars should not go from floor to floor + a lap as the G.C. contends that they should, in all the years I have in the reinforced concrete area low "lifts" are done in this way.

What is your take on this?    

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