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STRUCTURAL INSPECTIONS & DEFECTS
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CHIMNEY INSPECTION DIAGNOSIS REPAIR
COLUMNS & POSTS, DEFECTS
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DECK & PORCH CONSTRUCTION
DEFINITIONS of Mobile Home, Doublewide, Modular, Panelized
DEFINITIONS of ENGINEERED WOOD OSB LVL etc
DISASTER BUILDING INSPECTION & REPAIR
EARTHQUAKE DAMAGED FOUNDATIONS
FIRE DAMAGE vs MOLD DAMAGE
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FOOTING & FOUNDATION DRAINS
FOUNDATION CRACKS & DAMAGE GUIDE
FRAMING DAMAGE, INSPECTION, REPAIR
GRADING, DRAINAGE & SITE WORK
HOUSE PARTS, DEFINITIONS
INSECT INFESTATION / DAMAGE
KIT HOMES, Aladdin, Sears, Wards, Others
LOG HOME GUIDE
MOBILE HOMES, DOUBLEWIDES, TRAILERS
MODULAR HOME CONSTRUCTION
MOISTURE CONTROL in BUILDINGS
PORCH CONSTRUCTION & SCREENING
PRE-CUT & KIT HOMES
RETAINING WALL DESIGNS, TYPES, DAMAGE
ROT, FUNGUS, INSECT DAMAGE
SINKHOLES, WARNING SIGNS
STAIRS, RAILINGS, LANDINGS, RAMPS
STRAW BALE CONSTRUCTION
STRESS SKIN INSULATED PANELS
STRUCTURAL WOOD ASSESSMENT
TIMBER FRAMING, ROT
TRUSSES, Floor & Roof
WATER ENTRY in BUILDINGS
Rot, mold, or insects: how do we distinguish among these types of infestation & damage on or in buildings? How do we distinguish between carpenter ants and termites, how do we identify carpenter ant damage, carpenter bee damage, powder post beetle or old house borer damage and termite damage. What building construction details increase the risk of insect damage, and how do we evaluate the extent of structural impact of existing insect damage on a building. Preventing damage by wood destroying insects (termites, carpenter ants, powder post beetles) by good design and by building maintenance is preferred to simple chemical applications around a property. When use of pesticides is required, there are some important choices.
Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.
Here we outline major topics of concern regarding insect infestation or insect damage and we link to more in-depth diagnosis and repair information.
For our complete list of building insect problem detection, diagnosis, repair & prevention articles please see the detailed article links listed at Related Topics beginning beneath INSECT INFESTATION / DAMAGE.
If we do see insects in or on the building, it's pretty easy to tell CARPENTER ANTS (stomping around boldly in view, often near water or a sink or tub drain indoors) from a TERMITES (rarely in view unless swarming, but may fall out of a disturbed mud tube).
If you want a single rule, ants have a segmented body with a very very narrow waist (below left) while termites look more wormlike in their body (below right). CARPENTER BEES look like a big slow-moving non-aggressive bumble bee. A female carpenter bee is shown in our third photograph. You won't see POWDER POST BEETLES just their dust and damage.
The first course in recognition of types of insect activity in or on a building is often the observation of the actual damage to wood materials in the structures. That's because depending on the type of insect, season, temperature, and other conditions we won't always see the wood destroying insects themselves.
Insect Damage Photos
At below left you can see typical powder post beetle or old house borer damage to a wood joist or beam. At below right you may notice the characteristic mud tubes we associate with termite damage.
Below our photos illustrate typical carpenter ant damage (below left) and termite damage (below right).
Wood Rot Photos
Below our photos illustrate typical wood rot. All wood rot is caused by wood decaying fungi, typically basidiomycetes, some assisted by certain bacteria.
Wood rot (below left) tends to show breaks in the wood grain across the grain and in more or less rectangular forms.
Insect damage involves holes penetrating the wood and removal of the softer summer wood, tending to leave latewood or winter-wood behind to form walls and galleys (below right where my pen points to remaining hardwood).
Watch out: because moisture is involved in most wood destroying insect infestations (excepting drywood termites), you may find multiple sources of wood damage all together: wood rot along with termite or carpenter ant damage. (Carpenter bees prefer more dry wood and burrow right through both winter and summer wood in a board).
How do We Determine the Difference Between Carpenter Ant Damage, Carpenter Bee Damage, Powder Post Beetle Damage & Termite Damage in Buildings? Comparison photos:
For this discussion please also review the example photographs we provide above showing all of these insect types and what their damaged wood looks like. Also see the individual articles for each insect or topic. Carpenter ants, carpenter bees, termites, even powder post beetles or old house borers all provide visible indications of insect activity such as entry or exit holes, mud tubes, or the presence of the insects themselves.
How do We Evaluate the Extent of Insect or Rot Damage on or in Wood Structures? Structural Damage Assessment Procedure
The general approach to repairing damage from wood destroying insects involves these steps:
The Point of View of the Termite Inspector May Affect the Strategy as Well as The Cost to Cure an Active Insect Problem
Watch out: Many of the large number of expert sources available on the detection and prevention of building damage from wood destroying insects (see References, related articles) have been written from the viewpoint of academics or by pest control and related industry associations.
These experts offer valuable information about insect pests, often from the pest control operator's viewpoint.
Our own point of view is that of very experienced building inspectors, diagnosticians, and repair contractors.
Taking this more broad view of the topic adds two benefits: an improved ability to detect insect infestation by knowing where to look (as do experienced pest inspectors) and additional options that may reduce the ultimate cost of building insect damage repair or insect damage prevention.
Example of WDI Inspection Report Concluding Treatment of Active Infestation was Not Feasible
During a building inspection for a home buyer in Hyde Park, NY the pest control inspector (from a local pest control operator or PCO) observed termite infestation in the first floor structure of a home. He also observed that a private water well was located just a few feet from the foundation wall. This pest control operator issued a "WDI Termite Report" report that concluded:
Needless to say, the home seller, buyer, realtor, were all quite upset with this result. What was less obvious was the thinking of the PCO which went as follows:
In other words, as the adage [with some rewording] goes:
But wait! Let's go back to the original adage:
I [DF] was asked for a "second opinion" about the un-solvable termite problem at this Hyde Park home. I am no smarter than the PCO inspector, and I saw the same things he did.
But I also noticed and confirmed by some probing and poking into the area of damage that the actual termite infestation had entered up one narrow area of the foundation wall and entered the wood floor structure beneath a leaky toilet in a first floor bathroom. The entire area of infestation was less than ten square feet of material. That suggested an alternative five-step solution to the active termite problem, a "carpentry approach" and perhaps for that reason, one that the PCO had not considered.
5-Step Termite Damage Repairs Without Requirement for Chemical Treatment
The building owner hired a contractor who cured the termite infestation by the following steps:
Following these repairs the building owner hired the same PCO to perform a follow-up inspection. All of the investigation, repair, and PCO report documentation was provided to the home buyer and buyer's lender. The result was a "clear" or no infestation found report, permitting the home sale to proceed.
Frequently Asked Questions (FAQs) about Wood Destroying Insects or Insect Pests on & Around Buildings
Question: can you identify the type of insect that appears to have infested this wood seen in our attic?
What kind of pest do you think makes this? - MJS 10/24/2012
I can't say, MJS, but what is quite apparent from your photograph is that what appears to be insect activity, perhaps from a type of borer beetle, occurred before the tree was harvested and cut into lumber.
You can see that the flat sawn and planed surface of the wood has left cross-sectional slices of exposed, sawdust-filled voids in the wood. To me the damage looks like a type of wood boring beetle, powder post beetle or old house borer, but that's uncertain.
We publish your photo here to invite other readers to comment, and I'll also review our text library for some comparison images of similar wood damage.
Questions & answers or comments about the recognition, cause, & prevention of rot, fungus, mold or insect damage in buildings.
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Technical Reviewers & References
Related Topics, found near the top of this page suggest articles closely related to this one.