Many of us are familiar with Exterior Insulated Finishing Systems (EIFS), the stucco look finish applied to homes as a siding material. When it first hit the commercial scene around 1969 it was a cost effective and flexible design with a greater environmental benefit than other claddings. Unfortunately the installation is precise and far too many contractors were installing it incorrectly. Many failures occurred, and when it hit the residential scene homes suffered (and still do) from moisture intrusion which leads to fungi and mold issues. An associate showed us pictures of a home less than a year old that had mushrooms already growing in the walls! Now for the bad news…….
Adhered Concrete Masonry Veneers (ACMV) is the new bad boy on the block. Although it has an appealing look, like that of an old stone house, it should be treated as a stucco finish and all the trouble associated with EIFS will pale in comparison as the clock runs. Mark Parlee says in the Journal of Light Construction magazine, “…ACMV…will make the EIFS problems look like a drop in the bucket.” Again, it’s not that the material is a problem, it’s the installation. When an inspector sees EIFS and now ACMV, it is a red flag and further evaluation is almost the rule of thumb. Mark is an expert in exterior remediation and his well written article delves into the factors contributing to the failures and what can, or should be done. Too often the home is occupied and the occupants may already be suffering from poor air quality issues directly related to the moisture issues caused by ACMV.
Repairs can run into the tens of thousands of dollars if these issues have gotten out of hand. So what can a homeowner do? If you are shopping for a home, pay particular attention to (or insist that your inspector does) the exterior finish. Read up on what to look for. Since curb appeal is such a great seller, it is sometimes hard to look deeper. Most of us like the stone look…classy.
Because the stone itself can hold moisture, a good drainage system between the veneer and the framing is essential as it prevents the moisture from being drawn into the house. Short of a forensic analysis however, you may not be able to tell what the sub finish is, but there are things you can look for. If you are unsure have a qualified ASHI Home Inspector check it out for you.
1- Does the veneer (either EIFS or ACMV) have clearance at the bottom? A minimum of 2” is recommended above hard surfaces and more at an earth grade. It should NOT be below the mulch or the finish grade and an appropriate weep screed needs to be doing its job.
2- Where roofs abut vertical walls an appropriate ‘kick out’ flashing should be installed.
3- Check and maintain caulk and sealing around doors and windows.
4- Tops of walls, inside corners and rake returns are other culprits.
5- Is any lath visible between the stones?
You need not have several faults to have an issue. Even one fault in the siding can have unwanted consequences. Do yourself a huge favor and look/ask before buying and look/fix if you are already an owner.