Water coming into the house during rain is the most serious drainage problem on this site. It can damage flooring, walls and belongings, and it can lead to mold.
If water is entering now, focus on safety and limiting damage first. Then find the drainage cause.
What you may be seeing
- Water at exterior doors or under baseboards
- Wet carpet or flooring along an exterior wall
- Water through weep holes or slab joints
- Water stains on interior walls
- Musty smells after rain
- Water rising outside to slab level
First question: is water coming in at a door, through a wall, or up through the floor?
Water at doors usually comes from patio, porch or driveway runoff. Water at the base of walls often means the outside soil or mulch is too high or water pools against the house. Water through the floor needs professional evaluation.
If water comes in at a door
The surface outside the door slopes toward the house or is flooded.
Possible causes:
- Patio or porch sloping toward the door
- Driveway or walkway runoff
- Missing or failed threshold seal
If water comes in at the base of walls
Water is pooling against the house above the slab level or reaching weep holes.
Possible causes:
- Soil or mulch above the slab
- Downspouts at the foundation
- Negative grade
If water appears through the floor
Water under or around the slab is finding a path in.
Possible causes:
- Saturated soil around the slab
- Plumbing leak (rule out)
- Slab cracks or joints
Safety first
Turn off power to wet areas if outlets or cords are in water, and don't walk through standing water near electrical equipment. Document the damage with photos for insurance before cleanup.
Rule out plumbing
If water appears without rain, it may be a plumbing leak, not drainage. A plumber can test for leaks.
What you can check yourself
Only check these safely and after rain has stopped. Do not dig near marked utilities, and do not go near electrical equipment that is standing in water.
- Photograph water inside and outside during rain
- Check that soil and mulch are below the slab and weep holes
- Check downspout discharge points
- Look at the slope of patios and walkways at doors
- Confirm the water only appears during or after rain
Answer 20 quick questions → to get a preliminary drainage assessment.
What a drainage professional may evaluate
- Trace the water path from the source to the entry point
- Grade measurement around the house
- Downspout and surface drainage assessment
- Recommendation for restoration and, if needed, foundation or plumbing specialists
Most common causes
Grade toward the house
Water runs to and pools against the slab.
Roof runoff at the foundation
Downspouts or missing gutters.
Hardscape sloping toward doors
Patios and walkways sending water to thresholds.
Soil above the slab
Beds built up over weep holes and slab edges.
Yard flooding
The yard floods high enough to reach the house.
Possible solutions
The right fix depends on where the water comes from, where it collects and where it can legally and physically go. These are the solutions most often considered:
Regrading
Lower soil and mulch below the slab and slope it away.
Downspout drainage
Move roof water away.
Trench drains at doors
Intercept patio or driveway water before the threshold.
Surface and French drains
Remove water collecting near the house.
Threshold and seal repairs
Combined with drainage fixes for door entries.
When to call a drainage professional
- Water has entered the house
- You see mold or musty odors
- It happens in normal rain
- You can't find the source
Frequently asked questions
What should I do first when rainwater comes into my house?
Make the area safe, stop more water from entering if you can, photograph the damage, dry the area and contact your insurer if needed. Then get the drainage evaluated.
Can drainage problems cause mold?
Repeated moisture inside a home can lead to mold growth. Drying quickly and fixing the source is important.
Who do I call: a plumber, a roofer or a drainage company?
If water appears only during rain from outside, start with a drainage evaluation. If it appears without rain, call a plumber. Roof leaks show up from above.
Bottom line
Water entering the house is urgent. Make it safe, then trace the water's path from outside and break it with grading and drainage.
This page is educational and does not replace an onsite evaluation. Conditions, codes and HOA rules vary by property.