Split Face Block Veneer

[Jerry Simon]

Wood frame house with what appears to be a split face block veneer (approx 3-4" thick block veneer installed atop a concrete foundation up against a wood stud wall).  Some of the block is stained brown, and a few of the weep-screeds are stained brown.  Appears staining is from wood components (tannin) or corrosion from lintels behind the veneer?

Flashings and weeps appear to be well done.  Any concerns with this being split-face block (versus structural concerns with a structrual split-face block)?

[Jim Katen]

Could be asphalt from the felt? 

[Mike Lamb]

My concern would be water absorption since SFB is like a sponge. Depending upon the time of year and weather conditions, I would assume a lot more water would gather behind the veneer.

Some SFB is manufactured with a water repellent.

[BADAIR]

discoloration could be anything

recently had separate black brick veneer with black mortar & natural austin stone veneer with white mortar gigs that browning-yellowing all of a sudden appeared post-construction at isolated hi-mid-low areas of brick, stone, mortar materials

no moisture intrusion bleed & not a thing w/vb, sheathing or from the required 1 1/2" void was found after invassive-destructive testing, bricks & stones were removed

the culprit was determined to be the "slag-slop" mortar cleaning products used by the masons

they're removing all affected materials...

Edited July 24, 2021 by BADAIR

[mgbinspect]

It seems to me that if the staining was caused by moisture behind the veneer, only the very bottom of the plastic insert in the weeps would be stained along with the very bottom of the course of block resting on the flashing.

Sometimes irrigation systems cause staining like this if they are on a well, which is done here near the coast.

Split faced concrete block are indeed porous, but it takes a whole lot of rain to cause water to significantly penetrate 4" of masonry. When it does, the real cause is typically head joints that are not full, which is also true of brickwork. Properly installed masonry rarely permits significant water penetration, but poorly installed masonry can be a nightmare.