Someone sets a glass on the kitchen counter and watches it creep. A guest mentions that the hallway feels downhill. A child’s ball rolls to the same corner every time. Most sloping floors in Del Mar are discovered that way, by accident, and the discovery tends to arrive with a question that is too large to answer at once: is something wrong with the foundation?
It is better to break that question into smaller ones. This entry sets out the first few, in the order we find most useful. Our page on sloping floors describes the kinds of houses where slopes appear and how they are corrected.
A marble on the floor is a beginning
A marble or a ball is a fine way to notice a slope and a poor way to measure one. It responds to tiny irregularities in a board, a seam in vinyl, or a threshold. A long level, a laser level, or a simple water level gives numbers that can be compared later. If you are going to take only one step after reading this, take readings at the same handful of points in each room and write them down with the date.
The first question: old slope or new
Del Mar’s housing is old. Recent Census estimates (the 2020 to 2024 American Community Survey) count about 2,550 housing units in the city, and roughly three-quarters were built before 1980. About one in ten dates from 1939 or earlier.
A house that old has had a long time to settle, dry, and be remodeled. Many slopes in older Del Mar homes are decades old and no longer changing. A floor that has leaned the same way for thirty years, with paint and trim that show no fresh damage, is a different matter from one that has started to lean this year. So the first question is not how much the floor slopes. It is whether the slope is still moving.
Clues that a slope is old include trim that was scribed or shimmed to fit it, doors that were cut at an angle long ago, and cracks that have been painted over several times. Clues that it is recent include fresh cracks, doors that have just started to stick, and gaps that weren’t there last season.
One room, one wing, or the whole house
The second question is about extent. Walk the house with your readings in hand.
- One room only often points to something local: a sagging joist, a removed wall, a leak under that floor, or a post that has settled.
- One wing or one end suggests that part of the foundation is behaving differently from the rest, perhaps an addition on its own footings or a corner on different ground.
- The whole house tilting one way is less common and worth an earlier conversation, particularly on a hillside lot.
Additions deserve special attention in older Del Mar houses, which are sometimes enlarged more than once. The joint between old and new is where a step or slope tends to show first.
Which way does it fall
The third question is direction. A floor that falls toward the downhill side of a sloping lot, toward the ocean side of a bluff property, or toward a canyon is telling a different story from one that falls toward the middle of the house. A slope toward the center of a raised floor can suggest interior supports that have settled or framing that has sagged. A slope toward an outside wall more often involves the perimeter footing or the ground beneath it.
Note, too, whether the slope lines up with plumbing runs or a bathroom. Long-term leaks can soften soil or wood under a floor without much visible sign above.
What the house stands on in this part of Del Mar
The County’s 2023 hazard plan annex for Del Mar rates expansive soils a medium hazard, with limited extent and occasional occurrence. The same annex identifies the areas with the greatest potential for ground failure as the coastal bluffs, areas of the Del Mar Formation and Torrey Sandstone where slopes exceed 25 percent, and terrace escarpments of colluvium and slope wash in Crest Canyon and on the northeast side of the Del Mar Hills.
The California Geological Survey describes the Del Mar Formation as a dusky yellowish-green sandy claystone interbedded with sandstone, named for exposures in the sea cliffs at Del Mar. A claystone like that can respond to changes in moisture. None of this means a given house has a soil problem. It means the ground under Del Mar homes varies within short distances, and a floor slope on a hillside lot near a mapped slope area is worth understanding sooner.
Under the floor: framing questions
Many older Del Mar homes have raised wood floors over a crawl space. In those houses, the floor framing can be the whole story or part of it. The state residential code sets out how floor joists must bear on their supports, for example a minimum bearing length on wood or metal and a longer one on masonry or concrete, and it calls for floor framing to be supported and connected in specific ways. Over decades, notched or cut joists, removed posts, and moisture damage at the sill can all produce a slope that has nothing to do with the soil.
A look into the crawl space, with good light and a camera, usually tells you which kind of problem you have. Our earlier entry on crawl spaces under old Del Mar cottages describes what to look for there, and our raised foundation repair page describes the work.
Keeping a record between visits
If the house is a second home, occupied for part of the year, that makes a written record more valuable, not less. A simple method:
- Choose five to ten fixed points across the house and mark them discreetly.
- Take level readings at each point on every visit, using the same tool.
- Photograph any cracks near those points with a ruler in view.
- Note the season and any recent heavy rain.
- Ask a caretaker to repeat the readings after major storms.
Our second-home structural monitoring page and our earlier remote owner’s checklist offer more on keeping watch from a distance.
When to bring in help
It is worth arranging an evaluation when readings change between visits, when new cracks appear near the sloped area, when doors begin to bind, when the slope runs toward a slope or canyon edge, or when you are planning a remodel that would cover the floor. In the City of Del Mar, plans must be reviewed by the Planning Department before a building permit request goes forward, according to the City’s Building Services page, so it helps to understand the floor before design begins. We coordinate with licensed engineers as needed when the readings point below the framing.
Factors that shape a leveling scope
- whether the slope is old and stable or still changing
- foundation type and access to the crawl space
- framing condition, including sill and joist damage
- the soil and slope setting of the lot
- additions and how they join the original house
- moisture sources such as leaks or drainage
- whether foundation settlement repair is needed or framing work alone will do
- Planning and building review steps, which the City decides
We serve all of Del Mar. If a floor in your home has begun to lean, or you would simply like to know whether an old slope is resting, arrange a Free Quote.