· by Michael Blair, Nashville's Masonry
Manufactured stone veneer is a reasonable product with a poor reputation, earned almost entirely through bad installation. It is a cladding, not a waterproof layer, and what sits behind it decides whether the wall survives.
It is not waterproof
Water passes through veneer and mortar and reaches the wall behind. The assembly must therefore include a water-resistive barrier and a drainage path, exactly like any other cladding.
Veneer installed directly onto sheathing with no barrier and no drainage plane is the classic failure, and it rots the wall invisibly.
The details that matter
Two layers of water-resistive barrier or a drainage mat, a weep screed at the base to let water out, and flashing at every opening and transition.
The base of the veneer must stop short of grade — commonly four inches above soil and two above paving — so it does not wick moisture from the ground.
- Water-resistive barrier with a drainage plane behind
- Weep screed at the base, left clear
- Flashing at windows, doors and transitions
- Veneer stopped short of grade, not run into the soil
- Kick-out flashing where a roof meets a veneered wall
What failure looks like
Staining at the base, efflorescence, stones loosening, and eventually soft sheathing behind. By the time it is visible from outside, the sheathing has usually been wet for years.
A veneered wall running straight into the ground with no visible weep screed is worth investigating regardless of appearance.
Veneer versus full stone
Full-bed natural stone is a masonry wall with its own structural requirements and needs a foundation ledge to sit on. Veneer is a cladding hung on the wall.
Veneer is far cheaper and entirely legitimate, provided it is installed as cladding with all the water management that implies.