Foundation Watch: Cracks Claremont Owners Shouldn't Ignore

Foundation problems occupy a strange place in a homeowner's imagination: simultaneously the thing people fear most and the thing they are least equipped to assess. The result is two opposite errors that show up constantly in Claremont houses. Owners panic over shrinkage cracks that were there when the concrete cured and will still be there in another lifetime, and owners ignore the doors that have started sticking every winter, which is a much better clue than any crack. The useful skill is not diagnosis — that belongs to a structural engineer — but OBSERVATION: knowing which foundation type you have, what the symptoms actually are, and what sequence of calls produces an honest answer rather than an expensive one. This article covers all three. It deepens the maintenance hub and its owner's guide. Nothing here is an engineering opinion about your house; a licensed structural engineer provides that.

Two foundation types, two vocabularies

Claremont's housing stock divides cleanly. RAISED PERIMETER FOUNDATIONS, common on the older homes near the Village and through the earlier neighborhoods, carry the house on a stem wall with a crawl space beneath the floor, interior piers holding up the middle, and wood framing sitting on a sill plate on top of the concrete. SLAB-ON-GRADE, which dominates the postwar tracts, pours the floor and the footing as a single mass sitting directly on prepared soil. They fail differently and they are read differently. A raised foundation gives you ACCESS, which is a real advantage: someone can go under the house with a light and look at the stem wall, the piers, the girders and the sill plate directly, and inspect for moisture, rot and pest damage at the same time. Its typical problems are settlement at piers, deterioration of the stem wall, and moisture in a crawl space with inadequate ventilation. A slab hides everything, so its problems announce themselves through the floor above: cracks that telegraph up through tile or flooring, floors that have gone out of level, and the particular signature of a plumbing leak beneath the slab, which can arrive as an unexplained warm spot, an unexplained water bill or the sound of running water with everything shut off. Knowing which type you own is the first thing to establish, and it is on the inspection report from the day you bought the house.

What the symptoms actually are

Concrete cracks. It cracks as it cures and it cracks as the ground beneath it breathes with the seasons, and most of what an owner sees is exactly that. WHAT IS USUALLY BENIGN: fine vertical hairline cracks in a stem wall, shallow surface cracking in a garage slab, and small cracks that have not changed in years. WHAT DESERVES A PROFESSIONAL LOOK: cracks noticeably WIDER AT ONE END, which describes rotation rather than shrinkage; cracks where the two faces are OFFSET so that one side sits proud of the other; long HORIZONTAL cracks in a stem wall, which can indicate lateral pressure against the wall; stair-step cracking through masonry; and any crack that is measurably growing. And then the symptoms that are not cracks at all, which are frequently the better evidence: doors and windows that bind seasonally and then release, gaps opening between crown moulding and the ceiling or between the baseboard and the floor, tile grout lines cracking in a consistent line across a room, and floors that a marble rolls across on its own. PHOTOGRAPH AND DATE EVERYTHING. Movement is the diagnostic question — not size — and the only way to answer it is a record over time. An inexpensive crack monitor, or a pencil mark across the crack with the date beside it, converts an argument into data. Locally, the causes worth knowing: Claremont sits on an alluvial fan of variable soils, with clay lenses that swell when wet and shrink when dry, cycling hard through a Mediterranean year of soaking winters and rainless summers. Mature trees draw moisture unevenly from one side of a house. Drainage discharging against the foundation instead of away from it does more damage here than almost anything else. And a slow leak from an old supply line or a compromised sewer lateral can quietly saturate soil beneath a footing for years, which is where the repiping guide and the sewer line guide stop being plumbing topics and become foundation topics.

Who to call, in what order

THE SEQUENCE IS THE WHOLE ARTICLE. First, observe and document over a season or two if nothing is urgent — dated photographs, a monitor across the crack, notes on which doors stick and when. Second, when something warrants an answer, hire a STRUCTURAL ENGINEER, and hire the engineer BEFORE any repair contractor. This is the single most valuable piece of advice on the page. An engineer sells an opinion; a foundation repair company sells foundation repair, and asking a contractor whether you need their product is not a diagnosis, it is a quotation. Foundation work is a trade that gets both oversold and undersold, and an independent engineering report is what tells you which of those you are looking at. Third, FIX THE WATER FIRST WHERE WATER IS THE CAUSE. Correcting drainage, extending downspouts away from the house, regrading so the ground falls away from the foundation, repairing a leaking line — these are often the actual remedy, and doing structural work while the cause continues buys an expensive pause rather than a fix. Fourth, if repair is genuinely needed, have the engineer specify the scope and then bid that scope to contractors, so you are comparing identical work rather than competing sales stories, and permit it properly. On the transaction side, foundation history is a DISCLOSURE matter, and how it is documented changes what it costs you. A repair with a permit, an engineer's letter and an invoice reads to a buyer, an inspector and a lender as a solved problem. The same repair with only a receipt reads as unknown work, and unknown work gets discounted twice — once by the buyer and again by the appraisal. Keep the paper, hand it over, and let the file do the arguing, exactly as the selling guide recommends for every major system in the house.

Anthony Grynchal has been licensed in California since November 2009 and has seen more value destroyed by an undocumented foundation repair than by an honest disclosed crack. This is general information; a licensed structural engineer governs any judgment about your house.