Crawl Space Inspection Findings
This is a brief description of conditions commonly found during inspections by Crawl Space Portland.
Furnaces located in garages frequently have gaps in the rear sheet metal that allow rodents to travel freely between the garage and crawl space. When you also have gaps under the garage door you will always have a mouse or rat invasion, although you might not be aware of it for some time.
It is common to find damaged and leaking stove and dryer vent hose, and dryer vents with broken flappers. Clothes dryers can pump a lot of hot moist air into your crawl space. This encourages mold and insect invasions. The old dryer vent on the side of your house is often stuck open. This vent flap is supposed to keeps rodents and cold air out. A partially plugged vent dramatically increases the time it takes to dry a load of clothing and is a real fire hazard.

Pier and support posts for houses in the Portland area are made of wood, unlike most of the rest of the country. Virtually none of them here are treated to withstand moisture, mold, or insects. Our inspectors see a lot of loose, non-weight bearing posts as well as crooked piers, posts with rotting wood at their base, and pier posts that only have one nail, or nothing, holding them in place to the floor support beam. In the older parts of South East Portland, we still find piles of river rock as a pier base with three or four different pieces of wood sandwiched in for a friction fit. Crawl Space Portland will provide a bid to address these issues upon your request.
‘Earth to wood contact’ is a descriptive term used in the construction industry. This just means there is wood touching the ground in your crawl space. This condition needs to be corrected because termites and other insects will find it and then invade the rest of the structure. Wood on the ground is likely to be constantly damp, and will grow mold that releases spores into the atmosphere. We find old form boards, used to pour concrete, left from the original foundation, and still in place. Wood scraps, cardboard, and any other type of cellulose or organic materials, are removed when we preform and crawl space cleaning and replace the vapor barrier.
If rats or mice have been living in your crawl space, they will have done damage to any insulation they can find. Insulation needs to stay fluffy with lots of air space in the material to be effective. Rodents compact insulation by running, playing, tunneling and nesting in it. Rats will leap up from the ground in a crawl space to grab, and tear off chunks of fiberglass insulation to make a separate nest in a wall or under the vapor barrier. Squirrels and roof rats will literally drag insulation out onto your roof as part of their nesting activities.
The other way rats and mice compact insulation, is to urinate and defecate on it, particularly in a nest. This bio-mass stinks, and if mother rat finds poison bait placed in the area, the young nursing rats will die in the nest before the mother dies. This larger bio-mass then attracts filth flies, and later on, other insects, like carpet beetles, that eventually invade your living areas. We specialize in safely removing this destroyed insulation and we can sometimes offer alternatives to replacing it.
Flexible heating ducts in crawl spaces are targeted by rats and mice because they are warm and feel soft. Rodents soon chew into them and gain access to the entire heating system in your house. This explains a lot of strange noises a homeowner might hear in the quiet of the night. It also explains the sudden nasty smell that seems to be worse in some rooms, more than others. Not only is the homeowner breathing the rodent smells, but that hole in the ducting is also sucking a lot of moldy and dusty air from the crawl space directly into the heating and cooling system. The effects of breathing this air on people with allergies is obvious.
During our inspections, Crawl Space Portland sees heating ducts that have fallen off or have been disconnected. Damaged ducts waste large amounts of expensive hot air into the crawl space, and out the foundation vents. And open ducting directly invites the rodents into your heating system. We will replace and repair these ducts as part of our service.
We see a lot of water in Portland Oregon crawl spaces. We can tell a lot about the source of the problem by the water marks and pools on the vapor barrier. Some homes have their crawl space flood every winter and think that they just have to put up with the dampness and mold smells. In many cases a poorly installed vapor barrier traps the water in pools that last for months after the water would otherwise recede.
We see three major sources for this standing water. Blocked and broken gutters and gutter drains are, by far, the most common cause of crawl space flooding. Cheap materials, tree roots, time, and burrowing rodents all contribute to the failure of drain systems. Poor site grading, sprinkler systems, and landscaping can all contribute to the water problem. It is seldom that we find that a natural high-water table to be the cause of crawl space flooding here in Portland Oregon.
Sump pumps can compensate for some incoming water causes, if they are properly installed and in good repair. However, we find that these pumps are almost never inspected or maintained, and they fail at a high rate. We can replace these old pumps with the newer technologies that are more efficient, and they will warn you when they fail, or are about to fail. Crawl Space Portland advises our customers to address the sources of the standing water first, and only rely on the pump as an emergency backup.
We are aware of the hazards of lead paint dust and asbestos in Portland homes over fifty years old. In some cases, we are required by law to perform certain tests. We are trained, and state certified to perform these tests and to properly submit samples to a laboratory if needed.
We have been inspecting and working in Portland crawl spaces and attics for over 27 years and are happy to share our experience and knowledge with you.