Disable ads (and more) with a premium pass for a one time $4.99 payment
For double wythe walls, a backfill measurement of 5/8" is suitable due to the structural needs and the need for proper drainage. Double wythe walls consist of two layers of masonry units that provide additional strength and insulation. When backfilling, it is essential to allow enough space for mortar joints, which are typically around 3/8". The extra 1/4" in the 5/8" measurement accommodates any potential movement and ensures that the backfill material does not hinder the structural integrity of the wall or create pressure points.
This measurement also assists in maintaining proper alignment and level of the walls while securing the overall stability of the structure. Adequate backfill helps in reducing the risk of moisture accumulation behind the wall, which can lead to deterioration or failure over time. It's also important to consider that the backfill material should be compacted correctly to avoid settling, which is another reason why a precise measurement like 5/8" is chosen—it allows for optimal compaction without overfilling the cavity between the wythe.