When Los Angeles finally gets a string of winter storms after months of dry weather, even flat Mid‑Wilshire lots can see water where it does not belong. If you own or are shopping for a home in Greater Wilshire or Hancock Park, you know many properties are older and sit on raised foundations or shallow slabs. A little planning can prevent moisture from becoming a costly foundation issue. In this guide, you’ll learn the essentials on grading, gutters, crawlspaces, and when to bring in specialists. Let’s dive in.

Why moisture matters here

Los Angeles has long dry periods followed by episodic winter storms. That stop‑and‑start pattern can create fast runoff and short‑term saturation around your home. In Greater Wilshire and Hancock Park, many homes date to the early‑ to mid‑20th century with raised pier‑and‑beam or shallow slab foundations. Flat lots, mature landscaping, and historic hardscape changes can push water toward the house if not managed.

Clayey or reworked fill soils appear in parts of the area and can hold moisture. Repeated wet/dry cycles can stress foundations and framing over time, especially where grading or drainage is not ideal. Your goal is simple: keep water moving away from the building and out of the crawlspace.

Grading basics for flat lots

A common industry guideline is to create a positive slope away from the foundation. Many pros target about 5 percent fall within the first 10 feet, which is roughly a 6‑inch drop. Treat this as typical practice and confirm site specifics with a licensed professional and local code.

Avoid building raised landscape beds directly against the exterior wall. Keep some exposed foundation or stucco height for inspection and to limit capillary moisture. Where paths, patios, or driveways slope toward the house, consider adding a channel or linear drain to redirect water.

Gutters and downspouts that work

Your roof can shed a surprising volume of water during an intense storm. Well‑maintained gutters and downspouts act as your first defense.

• Clean gutters before the wet season and after heavy leaf drop. Fix leaks and secure loose sections.
• Extend downspouts so discharge lands several feet from the foundation onto a surface that slopes away. Use splash blocks or extensions to reduce erosion.
• Where allowed, route downspouts to a permitted stormwater solution such as a drywell sized for local soils. Always confirm local discharge rules before connecting to any public storm system.

Managing surface and subsurface water

On many flat Mid‑Wilshire lots, surface drains help move water where grading alone can’t.

• Surface solutions: Channel or grate drains across patio edges and driveways can capture sheet flow away from the house. Catch basins help at low spots where water tends to pond.
• Subsurface options: French drains or perimeter drains can manage shallow subsurface flow. These systems require careful sizing, an appropriate outlet, and usually permits. Infiltration systems like drywells depend on soil percolation rates and often need professional evaluation.

Before digging, review local permitting and stormwater guidance. Installation that changes lot drainage or connects to public infrastructure typically requires approval and inspections.

Crawlspaces and sub‑floor ventilation

Many local homes have raised pier‑and‑beam foundations with crawlspaces. You’ll find two main strategies for keeping those areas dry:

• Ventilated crawlspace: Uses passive vents for air exchange. This historic approach can work on drier sites if surface drainage is well managed and vents are clear.
• Sealed or encapsulated crawlspace: A modern approach that adds a continuous vapor barrier across the soil and up the walls, seals vents, insulates rim joists, and controls humidity with dehumidification or by conditioning the space where code permits.

A continuous polyethylene vapor barrier is the minimum. While 6‑mil is a common baseline, many professionals recommend 10–20 mil or reinforced liners for durability. Overlap and seal seams, seal around posts and pipes, and fasten the liner up the foundation walls per best practice.

Humidity targets and insulation

Aim to keep crawlspace relative humidity below about 60 percent to limit mold and decay. Many pros target 30–50 percent when using active dehumidification. Ventilated crawlspaces typically insulate between floor joists and at the rim; encapsulated designs often insulate walls and rim, following current code guidance. If you see persistent dampness even after grading fixes, consider encapsulation with a dehumidifier.

Remember that groundwater or ongoing seepage is not a vapor‑barrier problem. That situation may require perimeter drains, a sump pump, or engineered solutions.

Early warning signs to watch

Catching small issues early saves money and stress. During your own walkthroughs or before listing, look for:

• Exterior signs: Standing water after rain, earth or mulch piled against stucco, grading that slopes toward the house, efflorescence on concrete, or step and horizontal cracks in masonry.
• Interior signs: Doors and windows that suddenly stick, diagonal cracks near openings, sagging or bouncy floors, musty odors, or visible wood rot at sills and joists.

Not all cracks are serious. Hairline or vertical cracks in older concrete are common. Diagonal cracks wider than about 1/4 inch, step cracking in masonry, or any crack with measurable sideways displacement should be evaluated by a structural engineer. Active leaks, persistent standing water, and visible structural wood rot are urgent.

Your first steps this season

Start with simple, low‑cost actions that make a big difference.

• Clean gutters and repair leaks before winter storms.
• Add splash blocks or downspout extensions to carry water several feet away.
• Pull back soil, plants, and mulch from the foundation edge; restore slight slope away from the house.
• Inspect for plumbing leaks under sinks, at water heaters, and at irrigation lines; repair promptly.
• Keep vegetation trimmed back to improve airflow and visibility along the foundation.
• Photograph cracks or suspected movement across seasons to track change.

When to call specialists

Some problems need professional eyes and permitted fixes. Use this quick guide:

• Call a licensed plumber for any active or suspected leak. Hidden leaks can saturate soils and drive settlement.
• Call pest control if you see evidence of termites or extensive wood damage.
• Call a structural engineer for enlarging or stepped cracks, noticeable floor sag, chimney separation, or if inspection reports flag foundation concerns.
• Call a geotechnical engineer when soils, settlement, or groundwater are suspected; they can recommend underpinning, drainage, or soil improvements.
• Hire licensed foundation and waterproofing contractors to execute engineered plans, install perimeter drains, sump pumps, or perform underpinning. Verify license and insurance and expect permits and inspections for structural or grading work.

For Los Angeles, many foundation repairs, grading changes, and new drainage structures require permits and inspections. Stormwater rules also affect how and where you discharge runoff. Plan ahead and coordinate with your engineer and contractor.

Buyer tips for Mid‑Wilshire homes

If you’re evaluating an older property, ask for direct crawlspace access during inspections. Request a plumber’s review when moisture or old plumbing is suspected. If the home shows foundation cracks or movement, consider bringing in a structural engineer and, where soils are in question, a geotechnical engineer.

Build potential grading corrections, gutter work, and moisture control into your repair budget or contingency. Documentation of prior permitted work, retrofits, and drainage improvements adds confidence when you decide to move forward.

Seller tips before listing

Simple, visible fixes go a long way. Clean gutters, extend downspouts, trim vegetation away from the foundation, and regrade small areas that slope toward the house. Repair active leaks and gather documentation for any past foundation, drainage, or plumbing work. If you obtain contractor assessments or permits for larger items, keep those records handy for disclosures.

Quick walkthrough checklist

Use this short list during a viewing or weekend maintenance:

• Do downspouts discharge several feet from the foundation onto sloped ground?
• Is there any standing water near the house after rain?
• Do patios, walkways, and driveways drain away or have channel drains installed?
• Are crawlspace vents clear or, if encapsulated, is the vapor barrier intact and sealed?
• Do doors and windows operate smoothly, and are there new diagonal cracks near openings?
• Any musty odors under the house or in closets that could signal elevated humidity?

Staying ahead of moisture is one of the best investments you can make in an older Mid‑Wilshire home. A few preventive steps each season, and the right specialists when needed, will help protect your foundation, your indoor air quality, and your long‑term value. If you’re weighing a purchase or preparing to sell, and want help coordinating the right inspections and repairs, connect with Unknown Company to talk through next steps in a way that fits your timeline and goals.

FAQs

What slope should I have away from my house in Mid‑Wilshire?

• A typical industry guideline is about a 5 percent slope for the first 10 feet, or roughly a 6‑inch drop. Confirm site specifics and local code before regrading.

How often should I clean gutters in Hancock Park?

• Clean before the wet season and after major leaf fall, then check after big storms. Homes with mature trees may need more frequent service.

Should I encapsulate my crawlspace in Los Angeles?

• Encapsulation is a modern, effective approach for persistent moisture. Use a continuous vapor barrier (often 10–20 mil), seal vents, and maintain humidity below about 60 percent. Follow local code and consult licensed pros.

Which cracks mean I need a structural engineer?

• Diagonal cracks wider than about 1/4 inch, step cracks in masonry, cracks with sideways movement, or any crack that grows over time should be evaluated by a structural engineer.

Do I need permits for drainage or foundation work in Los Angeles?

• Many foundation repairs, underpinning, major regrading, and new drainage structures require permits and inspections. Stormwater rules also govern where runoff can discharge. Coordinate with your engineer and contractor to comply.