Interior or Exterior Stucco Testing? Which one? BOTH!!!
What is all the fuss about which stucco inspection method is the best – or is proper? Seems to me, a 25-yr. licensed real estate home inspector in Texas, that the best methodology is to use BOTH!
As we have known for a long time, Infra-red technology cannot determine consistently whether or not water penetrates the fenestrations in hard coat stucco (or EIFS) – neither inside nor outside.
A Tramex Moisture Encounter, though it can reach, as per manufacturer’s literature, 1.15” into a substrate (on an interior wall inspection) is not deep enough to detect moisture and certainly not the density (or lack of density) of a wall sheathing.
Working from the inside using an 8” Delmhorst probe, an inspector can, through probe holes (not drill holes) reach through the interior wall, through the insulation, and touch both or either the sill/base plates AND the wall sheathing. The reason this is a good preferred method is:
1. Not drilling from the outside is less destructive to the stucco. Plus, I have seen
some awful repairs – noticeable repairs.
2. It is easier to obtain a reading because the wall sheathing, which spans the entire building and is the first to encounter water penetration (not the studs) that slowly spreads outward from the corners of fenestrations (water does not remain simply behind the studs as offered by other inspectors. The meter easily reaches these areas and also allows the inspector to determine the degree of damage.
3. When probing through the interior wall either under the sill or at the caulk line of the baseboard, the repair is simple and truly unnoticeable. Watch here
The Delmhorst BD2100, set on wood for stucco sheathing, then gives a moisture reading…the inspector through experience and knowledge can determine the resistance as the end of the probe touches…or sometimes protrudes through damaged wall sheathing.
Some exterior locations cannot be accessed from the inside, such as beams and parapet walls. These must be drilled from the outside – but overall there is less damage to the exterior of the structure. Watch here. https://youtu.be/SaErVRhBshc
So, as you can see…the answer is that BOTH methods can and should be employed for a complete test of the stucco system.
If you have any questions, please call me at 713-249-4267
Wendy Matson Martinez, Inspector
The Woodlands, Houston, Texas