Stucco cracks - when they're serious and when they aren't.
Updated: Jan 10, 2020
We are called to inspect stucco based on suspicious cracks. But are cracks in stucco really a hazard? Should you not buy a hard-coat stucco house that has cracks?
Cracks usually o have a meaning - a sign of something. However... "depending" ...cracks do not necessarily indicate water penetration or stucco failure. They need not keep you from purchasing a stucco home, but do need professional examination to help determine why the cracks exists. Let me explain, in order of importance:
1. Cracks that have "differential", meaning that the two surfaces on each side of the crack are unequal - usually indicates a severe problem that may original with the slab. These usually allow water penetration. The photo below was taken from across the street during an inspection. The homeowner may not have any idea the stucco wall is in bad shape! The cracks below emanate from a roofline that is below the parapet wall at the top. We would first suspect that the scuppers are leaking (gutter catchments) into the edge of the wall - could be flashing also. This is severe and easy to say 'don't buy this home" the cost ranges somewhere between $50-90,000 "depending"...
2. Cracks extending outward from corners of windows and doors usually mean that some movement has occurred (stucco has no "give", therefore it will crack when stressed). The challenge is to determine what the stress is - minor or major - such as slab? Interior or supporting structure deterioration? Or improper building practice (openings should have "butterfly" tapes at the corners to prevent cracks! A professional can determine this.
3. Cracks that are horizontal in many, if not most, of the perimeter walls of the house is usually a builder problem - the framing crew did not leave a gap between the sheets of wall sheathing! This in and of itself is not a reason to not buy a stucco house, however, if this is combined with other builder stucco flaws such as missing specialized stucco flashing - I would think twice. Other horizontal-type cracks, particularly on un-capped parapet walls usually indicate deterioration within. However, the horizontal cracks on this uncapped parapet balcony wall, show us that likely wood rot from within are the cause.
4. The most dangerous cracks can be found underneath beams and cantilevered walls. Vertical cracks at long beams spanning long distances likely indicate deterioration of the beam and should be invasively checked by a professional inspector. In the photo below, water penetration from the porch above caused severe cracks shown above the contractor-opened stucco that showed the framing to be completely deteriorated.
BOTTOM LINE - it is difficult for a home buyer or home owner to discern between a movement crack and a MOVEMENT crack caused by deterioration or slab movement - for this you need a professional with knowledge, the proper tools and know-how.