Understanding AMSV (Adhered Manufactured Stone Veneer)

AMSV (adhered manufactured stone veneer) looks great and has major curb appeal, but it can cause problems if not installed correctly. Here’s what to know, and how to spot and fix problems if your house has stone veneer.

What Is AMSV?

Adhered manufactured stone veneer (AMSV) is a lightweight, decorative stone made from cement that’s designed to look like natural stone. It’s attached, or “adhered,” to the outside walls of a home with mortar—much like a thick, stone-like siding. But it’s purely decorative; it doesn’t carry any structural load in the same way as stone walls do.

Why We Flagged It

AMSV is popular because it’s beautiful and versatile, but it must be installed carefully. If flashing, drainage layers, or mortar work are done incorrectly, water can sneak behind the stone and stay trapped. Over time, this can lead to hidden moisture and structural damage to the property.

Common Deficiencies

Here’s what we frequently see on homes with AMSV. (Note: These problems are caused by faulty installation, not the product itself):

• Missing or poorly installed flashing and weep screeds (These are metal or plastic pieces that direct water down and out of the wall.)
• Insufficient water-resistive barriers – Two layers of barriers are needed in most exterior applications
• Improper clearances – Stone that sits too close to soil, concrete, or paved surfaces can lead to moisture buildup
• Gaps or cracks in mortar joints – These allow water to penetrate.
• Lack of drainage space – It’s important that water does not pool up behind the veneer

How To Spot Problems

If your home has stone veneer, here’s how to do a simple visual check to spot any problems:

• Look at the bottom edge of the stone. There should be a small gap (often 2–4 inches above soil or ½ inch above paved surfaces).
• Check around windows, doors, and rooflines for pieces that divert water away from the house.
• Watch for cracks, loose stones, or missing mortar.
• After a rain, notice if water drains away from the stone, or if it seems trapped.

If you see missing flashing, stones touching the ground, or obvious gaps, contact a contractor.

What To Do If Problems Are Found

Call a professional if you spot problems or concerns with your stone veneer. This could be a licensed masonry contractor experienced in manufactured stone veneer, or a specialty siding or exterior cladding contractor with training in AMSV. Catching and correcting deficiencies early helps prevent costly structural repairs later.

If you need to find a professional to help with your stone veneer, check out my list of Trusted Partners.