Crawl space & moisture
Crawl space cleaning
Droppings, fallen insulation, torn plastic and debris bagged and hauled out from under your house.
Learn more →Multi-family crawl space services · Seattle & Puget Sound
What's under the building shows up in the units.
Damp soil, torn vapor barrier, fallen insulation and rodent waste under a building reach the units as cold floors, odors and complaints. We clean out, insulate and seal the crawl space, section by section.
- Cleanup, insulation and vapor barrier in one plan
- Usually done from exterior crawl space access
- Section photos for owners and boards
Laying vapor barrier in a condo building crawl space · Olympia, WAThe problem
One crawl space, many units above it
The crawl space under a multi-family building is shared ground. Moisture from the soil, a leaking drain line under one unit, or a rat run along the foundation affects every unit above it. Ground-floor tenants feel it first: cold floors, musty smells in closets, the sharp odor after a rodent dies under the floor. By the time those complaints come in, the vapor barrier is often torn and the insulation is hanging.
We treat the crawl space as one system. We inspect the whole footprint, then lay out a plan that can include cleanup, dead animal removal, rodent sealing, new insulation, a vapor barrier or full encapsulation. You choose the scope and the phasing, and every section is photographed so the owner or board can see the condition under the building without going down there.
Warning signs
Signs the crawl space needs work
Ground-floor complaints and maintenance tickets usually point here first.
- SIGN 01
Cold floors in ground-floor units
Fallen or missing floor insulation leaves the subfloor exposed to cold crawl space air.
- SIGN 02
Musty odor in lower units
Damp soil and wet insulation produce a musty smell that rises into closets and cabinets.
- SIGN 03
Dead animal odor
A sharp, lingering smell in one or two units often means a rodent died in the crawl space below.
- SIGN 04
Torn or missing vapor barrier
Exposed soil adds moisture to the crawl space every day of the wet season.
- SIGN 05
Standing water or wet soil
Water after heavy rain points to drainage issues that should be fixed before new barrier goes down.
- SIGN 06
Rodent droppings and runways
Droppings, burrows and chewed pipe insulation mean rodents are using the crawl space as a route into the walls.
Proof of work
See the difference
Drag the slider to compare. Illustrations of typical results on homes like yours.
BeforeAfterThe job, step by step Burien, WA
STEP 01
STEP 02
STEP 03
STEP 04How we do it
How we handle a multi-family crawl space
Inspect, clean, deal with moisture, then insulate and seal.
- 01
Inspect the full footprint
We go through the whole crawl space, not just the section under the complaint. We note soil moisture, standing water, the vapor barrier, insulation, rodent signs, dead animals, plumbing leaks and the condition of foundation vents, and photograph each area against a building plan.
- 02
Plan scope and access
You get a scope broken into options and phases. Most crawl spaces are reached from exterior access points, but some buildings only have hatches inside units or closets. We list those units and the dates we need them, so you can send tenant notices and arrange entry.
- 03
Clean and remove
Crew members in protective suits and respirators remove droppings, dead animals, debris, fallen insulation and torn vapor barrier. Material is bagged under the building and carried out through the access. Nothing is swept dry, because rodent droppings can carry hantavirus.
- 04
Address moisture and entry points
We flag drainage and plumbing issues that need a plumber or landscaper, and handle what's in our scope: sealing foundation vent screens and gaps against rodents, and preparing the soil surface so the new barrier lies flat and stays in place.
- 05
Insulate, cover and document
We install new floor insulation between the joists, held firmly in place, then lay a vapor barrier with overlapped, taped seams, or a full encapsulation where that is the chosen scope. Each section is photographed when done, and you get a report for the owner or board.
What you get
What a multi-family crawl space job can include
| Areas covered | Full crawl space footprint under one or more buildings |
|---|---|
| Cleanup | Droppings, nests, dead animals, debris, fallen insulation, old barrier |
| Rodent exclusion | Foundation vent screens, pipe penetrations and foundation gaps sealed |
| Insulation | Floor insulation between joists, batts or rockwool, held in place |
| Vapor barrier | New ground cover with overlapped, taped seams |
| Encapsulation | Sealed liner up the foundation walls where chosen as the scope |
| Moisture notes | Drainage and plumbing issues flagged for the right trade |
| Reporting | Before-and-after photos of each section, by building |
Diagram
- 1Floor insulation
- 2Vapor barrier seams
- 3Foundation vents
- 4Plumbing lines
- 5Exterior access
- 6Damp soil
Compare
Vapor barrier or full encapsulation
Both control ground moisture. Encapsulation goes further.
| Factor | Vapor barrier | Full encapsulation |
|---|---|---|
| What it covers | Ground surface, seams overlapped and taped | Ground and foundation walls, sealed liner |
| Foundation vents | Stay open | Usually closed as part of the system |
| Moisture control | Slows moisture coming up from the soil | Controls ground moisture and humid outside air |
| Best for | Fairly dry crawl spaces with sound framing | Damp crawl spaces or buildings with ongoing odor |
| Scope | Simpler and faster per section | More materials and planning per section |
Puget Sound homes
Crawl spaces in a wet climate
The Puget Sound is wet from October to May, and crawl spaces feel it. Soil stays damp for months and vented crawl spaces pull in humid outdoor air. Washington code requires a vapor retarder over crawl space soil, and many older apartment buildings and condo complexes have one that is decades old, torn by service techs or missing in sections. Without it, moisture moves into the floor framing and insulation, and the insulation gets heavy, sags and falls onto the soil.
Older Seattle neighborhoods have walk-up apartments and duplex conversions on vented crawl spaces with tight clearance, and many Snohomish and Pierce County townhome communities sit on long, connected crawl spaces. Both share one feature: problems spread under every unit. Doing the whole footprint at once, or in a planned sequence, avoids patching one section while the next one fails. We also look at gutters and downspouts emptying next to the foundation, a common and easily fixed source of crawl space water.
Pricing
What shapes the price
Crawl space jobs vary a lot. These factors set the price.
- FACTOR 01
Footprint and clearance
Larger areas and low clearance mean more crew time and slower work per section.
- FACTOR 02
Cleanup required
Heavy droppings, dead animals and fallen insulation add removal and disposal.
- FACTOR 03
Scope chosen
A new vapor barrier is a smaller job than full encapsulation with sealed walls and vents.
- FACTOR 04
Insulation replacement
Replacing floor insulation across the footprint adds material and labor.
- FACTOR 05
Access points
Exterior access is fastest; hatches inside units add scheduling and floor protection.
Great service. I highly recommend this company. Wish I would have found them years ago... Isaac, Kareem and Irving were professional, courteous, and friendly. Pricing was clear and there were no surprises. Very happy with our experience.
FAQ
Multi-family crawl space services: questions we hear
Still unsure? Call (800) 674-4933 and talk it through with us.
Do you need to go into units to work in the crawl space?
Usually not. Most multi-family crawl spaces have exterior access points or hatches in common areas. If the only access is inside a unit or closet, we tell you which ones in advance and protect the route. Tenants upstairs may hear the crew below the floor during work hours.
Does a crawl space need a vapor barrier in Washington?
Washington code requires a vapor retarder over the soil in crawl spaces. On older buildings it is often torn, partial or missing. We check the existing barrier across the whole footprint during the inspection and recommend replacement wherever it no longer covers the ground.
Should we encapsulate or just replace the vapor barrier?
It depends on how wet the crawl space is and what you are trying to solve. A new vapor barrier with sealed seams handles ground moisture for many buildings. Encapsulation adds a sealed liner on the walls and controls humid outside air too, which helps damp crawl spaces with ongoing odor. We show you photos and explain the tradeoff.
Can you do one building at a time in a complex?
Yes. Phasing by building is common. We inspect all the crawl spaces you want covered, rank them by condition and write the scope so you can approve one building at a time. The report shows each building separately, so the board can plan and budget the next phases.
What causes a dead animal smell in a ground-floor unit?
Usually a rat or mouse that died in the crawl space or in a wall cavity near the floor. We locate and remove the animal, take out the soiled insulation around it, treat the spot and seal the entry point it used. If more than one unit smells it, we check for activity across the crawl space.
Can you handle mold in the crawl space?
We offer mold remediation, and we look for growth on joists and subfloor during the inspection. Mold under a building is a sign of a moisture problem, so the fix includes the barrier, ventilation or encapsulation, not just cleaning the wood. If we find it, it goes into the scope with photos.
Related services
Often done together
Crawl space & moisture
Crawl space vapor barrier installation
New crawl space ground cover, 6-mil or reinforced, lapped at the seams and run to the foundation walls.
Learn more →
Crawl space & moisture
Crawl space encapsulation
A sealed liner on floor and walls, vents closed, a dehumidifier running. Recommended only where it pays off.
Learn more →
Multi-family
Multi-family rodent control
Trapping and sealing across apartments, condos and townhomes, with photo reports for managers and boards.
Learn more →Let's see what's going on up there.
Book a free inspection. We'll photograph your attic and crawl space and walk you through what we find, before you decide anything.