Many Snellville houses sit on a concrete slab, and many older ones sit over a crawl space of brick or block piers. The two need different termite work, different inspections and different moisture answers. A slab house is mostly a question of its perimeter and openings. A crawl-space house is a question of the wood and the air under the floor.
Key takeaways
- In the Gwinnett County school district geography, roughly 59% of housing structures were built from 1970 to 1999, and about 37% in 2000 or later.
- About 4% of those structures were built before 1970, so the pre-1970 house is a small part of the count even where older blocks cluster.
- A slab house's termite exposure usually concentrates at the perimeter, the expansion joints and the places where plumbing passes through the concrete.
- Native subterranean termites begin swarming in February or March and swarm during the day, so an inspection is worth booking before spring.
- A Georgia termite letter must describe findings in locations an average reader can find, and its attached diagram has to match the written report.
- The price is confirmed on site, in writing, before any work starts.
How can I tell whether my house has a slab or a crawl space?
A technician usually starts from the outside, looking at how the wall meets the ground and whether there is an access door or a row of vents low on the foundation. A house that sits directly on concrete has no open space underneath to inspect.
The clearest sign of a crawl space is an access door or a row of foundation vents in the brick or block skirt. A slab house typically shows a continuous wall line that meets the concrete at grade, with no opening a person could crawl through. Many houses are a mix, with a slab porch or garage attached to a crawl-space body, so the honest answer for some properties is both.
The answer decides which inspection makes sense. A slab house is examined mainly from the perimeter and from the points where pipes and wiring come up through the concrete. A crawl-space house needs someone who can get under the floor, so one of the first questions on the phone is whether that access is open and safe to use.
What does Gwinnett's housing look like by age?
Federal survey data for the Gwinnett County school district geography shows that most housing was built between 1970 and 1999, with a large share built since 2000. Only a small share predates 1970.
The American Community Survey dashboard from the National Center for Education Statistics, using 2018 to 2022 figures, puts roughly 59% of housing structures in the 1970 to 1999 bracket. About 37% were built in 2000 or later, and about 4% before 1970. Those are shares of brackets, not a median year built, so no single construction year describes the county. The geography is a school-district boundary, not the county line, so the figures describe most of Gwinnett County rather than every address in it.
Older stock sits in particular places. The depot cores of Lilburn, Norcross, Duluth, Dacula, Buford and Lawrenceville hold older houses, and so do the courthouse square and historic districts of Monroe and the college blocks of Oxford. Mid-century brick ranches are common in Tucker and Peachtree Corners, and farmhouse-and-barn stock appears in Walnut Grove and Jersey. A house in one of those places is more likely to be older than the county average, which is worth knowing before the inspection.
What pests are typical in a post-1970 house on a slab?
A slab house is usually a termite and perimeter question. Subterranean termites move through the soil to reach the wood, so the ground at the foundation edge and the openings in it get most of the attention.
The University of Georgia reports that native subterranean termites begin swarming in February or March and swarm during the day, without being drawn to lights. The swarm is often the first thing a homeowner notices, with discarded wings on a sill or a windowsill. A slab can limit some of the routes a termite takes into the framing, but it still has a perimeter of soil touching the structure. The joints and openings in that perimeter are where a technician spends most of the visit. More detail on swarm timing is in the termite swarm season guide.
The same post-1970 houses bring their own typical problems. A technician looks at expansion joints where the slab meets the foundation, at plumbing and wiring that pass through the concrete, and at brick-veneer weep holes where soil or mulch may be sitting against the wall. Open, sunny lawns are where fire ants tend to build mounds. The University of Georgia describes the goal for those ants as managing their numbers, not eliminating them, and the slab termite treatment page explains how the perimeter work is scoped.
What pests are typical in an older crawl-space house?
An older crawl-space house often shows problems in the wood that sits on brick or block piers, and in the damp air beneath the floor. Sills, band joists and piers are the parts a technician checks first.
The structure is the main concern. Sills, band joists and piers can carry termite damage or wood-decay fungi, and a dirt floor can hold moisture against the framing. A technician looks for soft wood, for standing water, for soil in contact with the wood, and for a vapor barrier that has torn or is missing. Wet soil gives wood-decay fungi better conditions to grow, which is why the crawl space is often the part of the house that needs the closest look.
The living pests differ too. Smokybrown and American cockroaches, rodents and wood-decay problems tend to go along with an older crawl space, and the palmetto bug guide covers the cockroaches in more detail. According to UGA Extension, the house mouse, the Norway rat and the roof rat all live in Georgia. A small hole with chewed edges is a sure sign of occupancy, and rats and mice usually hide by day and come out at night. University of California Extension guidance says to seal gaps larger than one-half inch to keep rats out and gaps larger than one-quarter inch to keep mice out.
What does a technician look at under the floor?
A technician looks at standing water, soil contact with the wood, the condition of any vapor barrier and whether the wood is soft. The visit starts with whether the inspector can reach the band joist and the piers at all.
Access comes first. Crawl-space height, whether the floor is dirt or covered by a vapor barrier, and whether there is standing water all decide how much of the space can be seen. If the crawl is too low to enter safely, a careful report says which parts were not reached. A report that leaves out the band joists or the piers, because they could not be reached, describes less of the house than it may appear to describe.
The findings are physical. A torn or missing vapor barrier, soil piled against a sill, wet ground under the joists and wood that is soft are the kinds of things a technician describes in plain words. This guide does not give moisture percentages or advice on whether vents should be open or closed, because those depend on the house and on what the inspection finds. The crawl-space moisture service is where a technician's description of the space turns into a recommendation.
How does termite treatment differ between the two house types?
Georgia's rules list several subterranean termite control methods, including soil treatment, wood treatment, baiting and an alternate application technique. The method depends on the house, its foundation and what the inspection finds.
Georgia's Structural Pest Control Commission rule 620-6-.04 lists the control measures for subterranean termites as comprehensive soil treatment, defined soil treatment, wood treatment or fumigation, baiting, and an alternate application technique. The state's contract guidance also names pre-construction soil treatment and pre-construction wood treatment. A slab and a crawl space are treated differently because the soil and the wood sit in different places relative to the house, and the method follows from that layout.
Retreatment rules add another layer. Under state guidance, a partial retreatment covers at least ten feet in each direction from the point of reinfestation. Rule 620-6-.07 requires a complete retreatment where a structure under contract is found to have three or more separate areas of active subterranean termite infestation within five years. Rule 620-6-.02 requires a written contract for each job, and a termite warranty-only contract carries an initial inspection with a diagram, an annual inspection and a conspicuous statement about treatment and repair limits.
Why do moisture problems differ between the two?
A slab house usually has moisture problems at the perimeter and the joints, while a crawl-space house has moisture under the floor that can reach the wood directly. The fix for either one starts with finding the water source.
On a slab, water tends to come in along the edge where soil meets the foundation, and at the openings that pipes and wiring make through the concrete. Brick-veneer weep holes blocked by soil or mulch are a common point to check. Grading and gutters that send water toward the foundation are worth a look during the same visit,.
In a crawl space, the question is what the ground under the house is doing. Standing water, damp soil in contact with the framing, a torn vapor barrier and soft wood all point to a moisture source that is still active. This guide does not make claims about moisture thresholds or about what encapsulation achieves. A technician describes the conditions in front of them and the options that follow from those conditions, and that description is the part worth asking for in writing.
What should I ask before booking a visit?
Ask whether the visit includes the crawl space or only the outside, whether the report will include a diagram, and how the price is confirmed. A visit the same day is possible when a technician is free, but no arrival time is promised.
Ask whether the visit includes access under the house or only the exterior. For a crawl-space house, an inspection that never enters the space leaves a large part of the structure unseen. If termites are found, the Georgia termite letter needs a diagram that matches the findings, so ask how the report will show the locations of what was found. Describing those locations in plain words is part of the rule, not an extra.
The license check is a public one. The Georgia Department of Agriculture runs a license search, and structural pest control workers are required to carry an identification card issued by the department while performing services. A caller can ask for the company's license details on the phone. The price is confirmed on site, in writing, before any work starts. Phones are answered 24/7 at (855) 974-4733, and the same guidance applies to any house, slab or crawl space.
Frequently asked questions
Can I tell a slab house from a crawl-space house from the street?
Often, yes. A crawl-space house usually shows an access door or a row of foundation vents in its brick or block skirt, while a slab house generally shows one continuous wall line that meets the concrete at grade. Many houses combine the two, with a slab garage or porch attached to a crawl-space body. A technician can confirm which parts of a house sit on which foundation during a visit.
Are slab houses safe from termites?
No house is free of termite risk. A slab limits some routes into the framing, but subterranean termites move through soil, so the perimeter, the joints and the plumbing penetrations still need attention. Native subterranean termites swarm in February or March, which is why inspections are often booked before spring. A slab does not remove the need for an inspection.
Why does a crawl-space house get more attention for moisture?
The ground under the floor is closer to the framing, so standing water and damp soil can reach the wood directly. A dirt floor without a vapor barrier, or with a torn one, leaves the soil exposed. Soft wood and wood-decay fungi tend to appear where that moisture stays. This guide does not give moisture percentages or vent settings, so a technician describes what is visible instead.
How old are most houses in Gwinnett?
In the Gwinnett County school district geography, roughly 59% of housing structures were built from 1970 to 1999, and about 37% in 2000 or later. About 4% date from before 1970. The figure covers a school-district boundary rather than the county line, so it describes most of the county and not every address. It is a bracket, not a median year built.
Do rodents get into crawl spaces more than slabs?
Rodents can enter either kind of house through gaps, but a crawl space is an open area under the floor that is reached through gaps in the skirt or through vents. Signs of rodents include a small hole with chewed edges, and rats and mice usually hide by day. University of California Extension guidance says to seal gaps larger than one-half inch for rats and one-quarter inch for mice. That guidance comes from California rather than Georgia, so treat it as a general reference.
What does the termite letter have to do with my house type?
The Official Georgia Wood Infestation Inspection Report is the document used to report evidence of wood-destroying organisms, and it is the basis for transfer of real property in Georgia. Its findings must describe locations that an average reader can find, and any attached diagram has to match the written report. Only a company licensed in the wood-destroying organisms category can issue it. Ask to see the diagram together with the report.
Sources
- National Center for Education Statistics
- University of Georgia Extension
- University of Georgia IPM
- University of California Extension
- Georgia Secretary of State
This guide is general information for Gwinnett County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.