Additions are common on Kingston’s older single-family stock, a family room, a mudroom, a garage-to-living-space conversion, built onto a house that already had a full basement. That addition usually sits on its own crawl space, a second, smaller foundation with a completely different set of problems than the basement fifteen feet away.
Pricing the job
Square footage, headroom, and existing moisture all affect price. We do not quote without seeing the space. A free inspection gets you a real number.
Why the addition’s crawl space is the weak point
A dirt floor with open vents lets outside humidity in during summer, where it condenses on cooler surfaces under the house, and lets cold air in during winter, which is why the room above often feels colder than the rest of the house no matter what the thermostat says. Moisture from the ground itself adds to both problems if the floor is not sealed.
The fix
A sealed vapor barrier goes across the dirt floor and up the walls, the vents get closed, and we pay close attention to the rim joist, the band of wood at the top of the crawl wall where a surprising amount of air leakage happens. Whether a dehumidifier gets added depends on the specific space. We confirm your town’s requirements before starting.
What we find behind a newer addition specifically
An addition built onto a Kingston house in the 80s or 90s often used whatever crawl space specification was standard at the time, which by today’s understanding is not a great one: open vents, a dirt floor, no vapor control. Newer does not mean better here, it just means the same outdated approach applied more recently. We treat a 1985 crawl space the same way we would treat one from 1955, because the underlying physics did not change even though the construction date did.
Signs to check before you call
Most crawl space problems get noticed from the room above, not the crawl space itself. A musty smell that does not clear with normal cleaning is usually the first sign. After that: condensation on cold water pipes or ductwork, insulation sagging or dark-staining between the joists, or a floor upstairs that has started to feel soft in one spot. Any one of those on its own is worth a look. More than one together usually means the space has been running wet for a while, not just since the last storm.
Frequently asked questions
Only the addition has a crawl space, the rest of the house is a full basement. Is it still worth sealing?
Yes. An unsealed crawl space affects the room directly above it the same way regardless of what the rest of the house’s foundation looks like.
Will this fix a cold room?
Often yes, and noticeably. A vented crawl space is close to having outside air under your floor.
Do I need a dehumidifier?
Depends on the space. We will tell you which one yours actually needs.
How long does the job take?
Most jobs run one to two days depending on size and access.
What a recent customer said
Got 2 quotes to encapsulate a dirt floor under my breezeway between my garage and house. 603 explained exactly what they were going to do and what products they were going to use. Pricing was extremely reasonable compared to the other quote.
Brian Dean, 5 stars, Google review
Get your basement dry for good
Free inspection, free estimate, and a written quote in your hands within 24 hours.
Housing unit mix: Census ACS 2023 5-yr (B25024). Review quoted verbatim, public Google review.
Common questions about crawl spaces
- Is a little water in a crawl space normal?
- Is a vapor barrier necessary under the subfloor?
- Is there a good ROI on crawlspace encapsulation?
- My home is on a crawl space; the problem is the $20k price tag. Is encapsulating a crawlspace worth the money?
- What are the potential disadvantages of having a crawl space under your house?
- What are the reasons for some houses having basements or crawl
- What are the top reasons for immediate house foundation repair and crawl space encapsulation?
- What challenges should I expect fixing squeaky floors in a house with a short crawl space?
- What is the difference between a crawl space and a basement?
- What is the difference between a moisture barrier and a vapor barrier?
- What should the humidity in a crawl space be at different times of year?
- Why, after so many years living without it, is crawl space encapsulation so recommended now, when it lasts 10-15 years and costs half of a foundation repair?
