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Powder post beetle old house borere damage photographs (C) D Friedman D Grudzinski Insect Identification, Infestation & Damage in Buildings
Recognition, inspection for infestation, structural damage prevention & cure

Rot, mold, or insect damage in buildings:

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.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Guide to Spotting, Evaluating, Repairing & Preventing Structural Damage from Insects

Carpenter Ant damaged wood © Daniel Friedman at InspectApedia.comThis page is the top level of our complete guide to insect problems found on or in buildings.

Here we outline major topics of concern regarding insect infestation or insect damage and we link to more in-depth diagnosis and repair information.

Article Contents

How do I Tell a Carpenter Ant from a Termite from a Carpenter Bee from a Powder Post Beetle?

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 normally be able to see POWDER POST BEETLES (but they're not bad looking) you'll just see their dust and damage.

Below from the left we illustrate carpenter ants, including swarming winged carpenter ants, a termite (sketch) and a carpenter bee.

Carpenter ants closeup photo © Daniel Friedman at InspectApedia.com ... Termite identification sketch © Daniel Friedman at InspectApedia.com ... Carpenter Bee closeup photo © Daniel Friedman at InspectApedia.com

Common flies such as cluster flies are illustrated separately

at FLIES, MOSQUITOES REMOVE or REPEL.

How To Distinguish Among Damage from Wood Destroying Insects, Mold, or Rot on or in Buildings?

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.

Powder post beetle old house borere damage photographs (C) D Friedman D Grudzinski ... Termite damage photographs (C) D Friedman D Grudzinski

Below our photos illustrate typical carpenter ant damage (below left) and termite damage (below right).

Carpenter Ant damaged wood © Daniel Friedman at InspectApedia.com ... Termite damaged wood © Daniel Friedman at InspectApedia.com

Also see COMPARE TERMITE DAMAGE to POWDER POST BEETLE

Wood Rot Identification Photos - "Brown Rot"

Below our photos illustrate typical wood rot.

All wood rot is caused by wood decaying fungi, typically basidiomycetes, some assisted by certain bacteria.

Watch out: you may find wood rot and insect damage together in a structure. But they are visually distinct.

Wood rot damage © Daniel Friedman at InspectApedia.com ... Wood rot damage © Daniel Friedman at InspectApedia.com

See details at ROT TYPES, BROWN SOFT WHITE

Photos Assist in Telling the Difference Between Insect Damage & Wood Rot

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).

Wood rot damage © Daniel Friedman at InspectApedia.com ... Carpenter Ant damaged wood © Daniel Friedman at InspectApedia.com

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).

Question: can you tell from these photographs if this is mold or "dry rot"? Our surveyor says the beam needs to be replaced.

Wood rot from leakage in a London home (C) InspectApedia JG

I have found your website most useful, and am emailing to ask your opinion (just from photos as am in the UK) with regards to suspect material on a timber beam. I appreciate you charge for consultations and I am happy to make a donation to your website if helpful.

I like in a top floor apartment in an 1850s terrace brick property in London. We had a leak in the Spring in the roof which damaged the front wall.

There are some exposed beams (although covered in plaster), part of the plaster was damaged exposing the beams and I partially painted the gap 3 months ago, a few days ago I noticed odd black stains with black looking hairs sticking out of it (see photos).

For photos on your website it looks like brown mold (but more black in colour), our surveyor is assuming it is dry rot and the beam needs to be replaced.

While it is hard for you to judge from photos, in your personal opinion what do think it is? Thanks so much for your help - J.G. 1/4/2014, London

Wood rot from leakage in a London home (C) InspectApedia JG ... Wood rot from leakage in a London home (C) InspectApedia JG

Reply:

A competent onsite inspection by an expert usually finds additional clues that would permit a more accurate, complete, and authoritative answer than we can give by email alone.

For example, to assess the scope of damage in the building you are describing one would want to trace the location(s) and extent of leaks and to perform appropriate probing tests

(STRUCTURAL DAMAGE PROBING)

to assess the depth & extent of actual structural damage to the beams involved. 

While manual probing is usually sufficient, there are also more sophisticated tools available

(WOOD STRUCTURE ASSESSMENT).

That said I offer these comments:

From your photograph there is no doubt that there has been protracted leakage as the fungal growth that I see involve mycelia or "root-hair" -like structures characteristic of wood destroying fungi on wet wood.

While mold growth can appear quite rapidly, when I see extended mycelial growth along with cracked wood characteristic of brown rot fungi it is reasonable to infer that the leakage in that area has been going on for some time.

At above left we see fungal mycelia on what looks like the back-side of a fragment of drywall.

At above right we see the same mycelia on the side of what is probably a wood beam - indicated in your first photo above.

We also see "cracking" in the wood characteristic of wood rot, typically caused by a wood-rotting fungus in the Basidiomycete family but possibly involving other fungal genera/species such as Stemonitis sp. that I often find in buildings.

I'd need to see the fungus under the microscope to identify it - a step that is not necessary to decide on the need for structural repair except where

MERULIPORIA FUNGUS DAMAGE is involved. As that fungus is a characteristic yellow-gold, I don't see evidence of it in your photographs.

"Dry rot" does not really mean that rot occurred with no moisture present, so use of the term can be misleading.

What we cannot assess from your photographs is the depth and extent of rot and thus the actual need for replacement of the structural members. Especially in older buildings where the depth of rot into large structural members is shallow, for example an inch or less in a 8x12 beam, generally experts will fix the leak and leave the beam in service.

Depending on the structure type, and with the caveat that I am not a structural engineer nor do I have the benefit of onsite view and exploration of your particular building, I caution that there can be special cases where structural repair could be more urgent.

For example, if the ends of wood beams set into a masonry structural wall are deteriorated, and particularly where angular fire cuts were made in the wood beam ends, should the beam end become rot deteriorated there could be a risk of structural collapse.

In sum, from the very limited visual access seen just in your photos, but noting the apparent age of leakage and evidence of wood rot, a more thorough investigation is needed to determine if structural repair is needed at all (other than leak repairs), and attention needs to be given to the collapse risk points and structural connections in the building.

Beware of the "OPM" problem - a consultant who spends other people's money to reduce his or her own risk beyond that justified by the actual site conditions.

Beware of the opposite concern - a consultant whose work is superficial and inadequate and who fails to adequately identify and assess actual risk of serious structural damage or hazards.

Reader follow-up:

Many thanks for your detailed and quick reply, it is immensely helpful and really appreciated. We have our original structural surveyor (from when we bought the property) returning next week but I note your comments re OPM...

as his instinctive reaction from just looking at the photo was that it needs replacing with a steel beam. We will get some more expert assessments on site so we can have a full view of what to do. I will keep you informed of our progress, - J.G. 1/4/2014

Reply:

The case you have described, of water intrusion detected at one end of a large wood timber in an older London home, is perhaps a perfect test case for Probett's approach to wood timber strength assessment described in the citation I include below

Before tearing out an existing structural wood beam for replacement with a steel I-beam as your surveyor (in my opinion a bit too glibly) recommended, it would make sense to explore further the condition of the beam and its connections.

As my earlier email explained, in a large wood timber, a modest depth of surface rot damage may not be at all enough to merit timber replacement.

As Mr. Probett's equipment and a knowledgeable user are probably not available in London, you may be reduced to a more traditional but still reasonable timber assessment approach that includes

- removal of enough finish materials to form a confident opinion of the location(s) and extent(s) of and history of leakage that affected the beam in question .

- a visual inspection to find water or rot damaged wood

- mechanical probing to explore the depth of that damage

- a thoughtful assessment of extent of timber damage and thus compromise of its strength compared with the design loads involved

- careful attention in particular to points of connection, as for example in the case you have provided, the detected leak is at one end of a large beam; even if the overall beam is un-damaged, a failure at the connection point could be catastrophic.

- an interior inspection of the building finished-surfaces for evidence of leakage or movement (stains, cracked, dislocated drywall or plaster, wall-floor separation, etc)

- an exterior inspection of the building to identify its leak points and leak history, with an eye to identifying other areas where there may be un-discovered leakage, rot, and structural damage that need to be investigated.

My concern in writing this follow-up note is to be sure to point out that on a building built in the 1850's there will certainly have been leaks through its lifetime; depending on leak location, duration, severity, building materials, interior finishing, building occupancy, building maintenance level and similar variables, such leaks can go un-recognized for a long time, possibly allowing damage to be significant. On the other hand, and where my comments began, superficial damage is likely not to justify costly repairs.

Because this case is a fit application for methods he is developing, I have referred Paul Probett to our public discussion at https://InspectAPedia.com/structure/Structural_Damage_Probing.php

If you agree I'd like to also send him a copy of our correspondence. See

Reader follow-up:

Daniel this is incredibly helpful, it is really good to get an understanding of all the various things to consider and from an unbiased source, it seems clear that each situation is different to the last and there is no 'boiler plate' solution that should be instantly applied.

While I have no expert knowledge of any of this, my instinct was that every scenario should be considered before the most invasive option of a steel beam, particularly from the structural reason that we are in an old property which has a tendency to move or expand a bit (unfortunately a curse of Islington in London all being built on clay) and hence the sheer weight of a steel beam might present its own problems on a house designed for timber and bricks, however as you rightly mentioned - surveyors, in the uk at least, want to present the best option to cover their personal liability regardless of cost

I certainly come with the view that whatever is necessary should be done (as the consequences of not doing so could be fatal) but the right solution should be found Please feel free to pass on our correspondence to Mr Probett - J.G. 1/5/2014

Difference Between Carpenter Ant Damage, Carpenter Bee Damage, Powder Post Beetle Damage & Termite Damage in Buildings?

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.

Carpenter Ant damaged wood © Daniel Friedman at InspectApedia.com

Carpenter ant damaged wood 

will show cleanly excavated wood passages - the frass is brought outside of the area of excavation.

And seasonally you'll find carpenter ants or carpenter ant bodies.

Details are at CARPENTER ANTS

Carpenter bee damaged wood 

will be on the exterior of the building, typically well above ground, in wood trim, siding, decks, etc.

Carpenter bee activity indicator © Daniel Friedman at InspectApedia.com

You will observe 5/16" to 1/2" diameter round holes, usually penetrating the edges of boards and when the bees are active you'll find coarse fresh sawdust below the working opening.

Details are at CARPENTER BEES

Powder post beetle damaged wood 

will show multiple tiny holes, about 1/8" in diameter, leaving the outermost surface of the wood otherwise intact.

Powder post beetle old house borere damage photographs (C) D Friedman D Grudzinski

Probing you will find powdery sawdust and damaged wood just below this skin.

The older the powder post beetle (or old house borer beetle) damage is, the deeper into the wood the damage will extend.

For this reason, strategic probing is important to assess the depth of damage to the wood and thus to the wood structure.

When powder post beetles are active you may see light dusting of fine wood powder around some of these holes as well as on surfaces below.

Details are at POWDER POST BEETLES

Also see COMPARE TERMITE DAMAGE to POWDER POST BEETLE

Termite damaged wood 

typically will include the presence of visible mud tubes and mud-like substance inside the excavated wood galleys.

Termite damaged wood © Daniel Friedman at InspectApedia.com

Because termites need to protect themselves from drying out and light they are not found on the exterior of wood under termite attack.

It's rare to see an active termite unless you disturb (break apart) a mud tube while it's in use - in that case you'll see pale termites fall out. You will see termites if they are swarming however. (Watch out for "winged ants" that are not).

Details are at TERMITES

Wood rot damage © Daniel Friedman at InspectApedia.comWood rot itself 

does not produce insect entry/exit holes nor mud tubes, but of course both wood rot and insect damage are often found together and may even be found within the same wood member or board.

Mold is a very broad kingdom of fungi, among which some molds, particularly the basidiomycetes are wood rotters.

So not all mold causes wood rot, but basically all wood rot in homes is thanks to one or more mold genera/species. (With some help from bacteria).

Details are at

Watch out: conditions that encourage mold growth in buildings, particularly chronic leaks or water entry, are an invitation to wood destroying insects as well.

How to Distinguish Dog Chewing or Biting Damage from Insect Damage to Wood

Dog chew damage to wood trim indoros (C) InspectApedia.com  Richard ig

Question: what caused this damage to wood in my home? Insects?

I am trying to figure out what caused the damage in the attached photographs.

Location is Columbia County, NY. There is no visible sawdust or debris, and I have not seen any insects. Any help would be appreciated. - Anonymous by private email 2018/10/17

Reply: bad dog! chewed wood trim

Dog chew damage to wood trim indoros (C) InspectApedia.com  Richard igx

Having seen damage done by nervous or irritated dogs who attack building components, trim, even drywall indoors and, of course, furniture, my bet is that a dog is or was at your property.

Reasons that this is animal damage not insect damage.

Bad dog!

The gouges into the wood are shaped as if penetrated by a roughly V-shaped or spike-shaped (sharp) tooth rather than coming from tunneling or wood-destroying insects. You will see other photos of typical insect damage of all sorts in this article series.

Other examples of animal biting, chewing, or digging that causes damage at properties as well as animal allergens, urine removal, and odors are discussed at

How to Recognize Carpenter Ants or Termites or Both in a Window Frame

Insect damage at window frame (C) InspectApedia John Huie

Question: Can you tell me what this damage to my house was caused by?

Can you tell me what this damage to my house was caused by? No insects visible and I have not found any similar damage elsewhere on the exterior of the house.

The moisture is from spraying dilute fipronil, there is no direct exposure to rain. Thanks for any help. - J.H., Athens GA, USA 12 Sept 2015

[Click to enlarge any image]

Reply:

That looks like termite mud tubes to me; It's unusual to find termite damage in a movable window sash.

I would be very careful to have a very thorough pest inspection: I suspect that if there is wood destroying insect damage in a window sash it is also more extensive in other structural features such as wall framing.

Dig out some of the "sawdust" shown in the lower part of your photo. If it's muddy and granular that suggests a termite mud tube. If the "sawdust" is carpenter ant frass it will be light, loose, fluffy material.

Reader follow-up:

Insect damage at window frame (C) InspectApedia John Huie Thank you for your help Daniel! I will probably get a professional inspection. Actually it is a fixed window not a movable sash.

Reply:

Keep me posted on what you're told, JH

If there is access to the house from below look in that area for more mud tubes and thus termites.

See TERMITE DAMAGE INSPECTION
and also

see CARPENTER ANTS

For examples of both of these insects and their damage, sawdust or frass, detection, damage inspection, treatment or control.

Reader follow-up:

It looks like these may be carpenter ants rather than termites... I dug into the wood a bit and pulled out some dead 'animals'... this photo

Insect damage at window frame (C) InspectApedia John Huie This photo may show a couple of different individuals, but you can see identifying characteristics of carpenter ants, ... They also appear to be have been active near my roof skylight which has (or had) a slight leak and from which I have sometimes seen sawdust drifting down.

Apparently they are not as destructive as termites.

I have some Fipronil which I bought to treat dog for fleas, but is sold for termite control. I will probably spray some cautiously to discourage these beasts. Feel free to use my photos or info on your website.

Reply:

Yes, your photo shows carpenter ants, but I thought I saw what might be mud tubes in the bottom of your window frame damage photo. If so there were termites.

Both of these insects can do tremendous damage to wood structures if left unattended. A layperson's description of a difference between carpenter ants and termites (among many) is that

In old wood damage we sometimes find both insects have attacked the wood.

DIY Treatment for Carpenter Ants or Termites using Fipronil and Pet Fea Powder

About using Fipronil to treat your carpenter ants or termites or both,

Fipronil is a broad use insecticide that belongs to the phenylpyrazole chemical family. Fipronil is used to control ants, beetles, cockroaches, fleas, ticks, termites, mole crickets, thrips, rootworms, weevils, and other insects. ...

Fipronil is used in a wide variety of pesticide products, including granular products for grass, gel baits, spot-on pet care products, liquid termite control products, and products for agriculture.

There are more than 50 registered products that contain fipronil. - NPIC, retrieved 26 Sept 2015 original source: http://npic.orst.edu/factsheets/fipronil.pdf

Watch out: sprinkling a pet flea powder, even though it contains fipronil, may not be effective for treating termites as in a pet use formulation it's in a vehicle and at a concentration intended for safe use on animals.

More, you may fail to find the total extent of insect damage and/or may miss the proper locations of application. Also you're skipping treating the cause: leaks or moisture, that invited insects into the structure in the first place.

If you are confident that the total area of infestation is trivial you can try an insecticide combined with steps to stop the water problem; but watch out for the possibility of more extensive hidden damage. When I find termites or carpenter ants in a window sash I figure that there's a good chance their activity was much more widespread in the structure.

See AMATEUR TERMITE TREATMENT WARNINGS

How do We Evaluate the Extent of Insect or Rot Damage on or in Wood Structures? Structural Damage Assessment Procedure

Meruliporia house eating fungus © Daniel Friedman at InspectApedia.comFor a thorough evaluation of the extent of structural damage to a building we should take the following steps:

5 Basic Steps in Repair of Damage by Wood Destroying Insects

The general approach to repairing damage from wood destroying insects involves these steps:

  1. Find and fix the cause 

    of insect infestation, typically an building leak of some kind
  2. Identify the areas of insect infestation 

    and the extent of damage, using a combination of visual inspection, probing, and where appropriate, demolition.
  3. Repair or replaced damaged structural and finish components as needed.

    During repairs, where feasible, amend the structure or design to reduce the risk of insect attack by reducing the risk of leaks, moisture traps, or wood materials close to the ground surface.
  4. If appropriate (see below), choose and implement an insect damage prevention strategy 

    such as termite shield, chemical barrier, use of insect resistant materials, etc.
  5. Reinspect periodically 

    to assure that there is no renewed wood-destroying insect activity

The Point of View of the Termite Inspector May Affect the Strategy as Well as The Cost to Cure an Active Insect Problem

Signs of risk of termite attack © Daniel Friedman at InspectApedia.com 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:

Active termite infestation, house cannot be treated.

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:

I see active termites and a well close to the foundation and also some dirt crawl spaces in the home. That means we cannot treat the home by conventional means (which for this PCO meant applying termiticide in the soils around the home).

I think they'd have to move the well - something that is very expensive, probably cost prohibitive.

And even then, I'd have to trench around the house and remove treat and return soil, as I can't just pump into the ground where there is a dirt crawl space.

The whole job, moving the well and soil trench treatment would be tens of thousands of dollars and I think it would just be too expensive for the value of the home.

In other words, as the adage [with some rewording] goes:

To a pest control company every termite problem needs to be solved by using pest control methods.

But wait! Let's go back to the original adage:

To a carpenter every problem looks like a nail.

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:

  1. Fix the plumbing leak 

    that had invited termites into the floor structure
  2. Demolish and remove all of the termite-infested wood, 

    e.g. flooring, consisting of a few feet of sill, subflooring, finish flooring, and one floor joist.
  3. Re-build the damaged area 

    using pressure-treated lumber for sill and joist repairs and conventional materials for the remaining repair
  4. Completely clean 

    all debris, sawdust, mud-tubes, etc.
  5. Provide a document 

    of all repairs made

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.

Nine Approaches to Prevention of Wood Destroying Insect Damage

  1. Architectural design to resist wood destroying insect attack: the best wood destroying insect resistant-building design is to keep wood and other insect-friendly materials at least 8" above ground (some areas permit 6"), provide no protected path for insect entry into the structure (such as behind solid insulation boards)

    See SIDING CLEARANCE TO GROUND
  2. Building maintenance: keep surface water and roof spillage away from the building perimeter. Do not pile up leaves, organic debris, wood piles, or mulch against building walls. Hire a professional to inspect the building, especially at high-risk points.
  3. BAIT TRAPS for TERMITE CONTROL - explains how termite bait traps are used to detect termites near a building; this method avoids use of chemical barriers but requires very reliable, regular inspection as the theory is based on detection (and changing the bait to a poison at that time) rather than prevention of insect attack.
  4. Chemical barrier that resists insect attack: is applied around and under the building. Chemical barriers for termites and other wood destroying insects used to work very well, but modern chemicals may be less effective/less durable over time due to changes in pesticides to make these chemicals less of an an environmental hazard.

    See PESTICIDE EXPOSURE HAZARDS
    and
    see TERMITE SHIELDS vs TERMITICIDE.
  5. INSECTS & FOAM INSULATION - discusses the problem of insects attacking a building through foam foundation insulation
  6. PRESERVATIVE TREATED LUMBER - describes using lumber treated to increase its insect resistance.

    Also
    see ROT-RESISTANT Deck Lumber & Flooring

    and for exterior decks and porches

    see SYNTHETIC DECK BOARDS, COMPOSITE PLASTIC VINYL.

  7. TERMITE SHIELD Installation describes how and where metallic shields are installed to make it more difficult for insects to enter wood framing from the ground or through the building foundation.

    While a termite shield does not absolutely prevent attack by termites nor other wood-destroying insects from the ground, the shield can force termites to build mud tubes around a visible flange making the attack easier to detect.

    A termite shield is simply a metal shield is set atop all wood sills, extending an inch or more past the building interior and exterior wall surfaces, bent on an angle downwards to shed water, with exact details specified by a pest control officer and installed during construction.

    A termite shield may be effective but remains a risky approach to bug-proofing if the shield is not inspected and if not kept visually accessible on both inside and outside of the buildings for periodic check - a termite mud tube might bypass a metal shield.
  8. TERMITE SHIELDS vs TERMITICIDE describes the use of chemical barriers or treatments to resist attack by termites or carpenter ants (different chemicals, different application methods must be used).

    Also see PESTICIDE EXPOSURE HAZARDS.
  9. Water & moisture control:

    It is no surprise that quite often we find that the primary point of attack by carpenter ants or termites on a wood structure is where there is or was a leak that wet wood members.

    Even in the case of powder post beetles, where leaks may not be immediately present, a history of high indoor or basement or crawl space moisture levels increase the risk of that attack.

    By keeping water away from the building foundation, fixing leaks that send water through the structure, and by keeping indoor humidity at appropriate levels we can reduce the attractiveness of wood and structural members to wood destroying insects, particularly carpenter ants and termites.

    Start by a complete and competent inspection of the building to identify existing leaks or moisture problems as well as construction details that invite a leak or moisture issue.

    See WATER BARRIERS, EXTERIOR BUILDING

    and
    see WATER ENTRY in BUILDINGS for our complete list of building moisture & water entry diagnosis & control articles.

 

Harmless Insect Activity: Bagworms, Insect Egg Cases & more

The following reader Q&A along with these photos describe other signs of insect activity at buildings, in these cases, generally producing cosmetic damage rather than damage to the structure. (General Reader Q&A on a variety of insect damage questions is listed after this section.)

On 2022-10-14 by InspectApedia-911 (mod)

@Igor,

In your photo I can see some normal drying splits or checking cracks in what looks like a floor joist.

I also see some extremely small black flecks, but I can't make out what they are.

And finally I think I see a cobweb with an ant trapped in it.

Take a closer look. If that ant is the insect that you are seeing, or if you are seeing sawdust or frass appearing under or on or near the wood framing, you may have a carpenter ant infestation.

On 2022-10-13 by Igor

I have been noticing odd holes in the truces of my home in northern NY but I am having trouble identifying the insect because I haven't seen anything crawling around.

holes in trusses (C) InspectApedia.com Igor

On 2021-12-16 by Inspectapedia Com Moderator - soffit damage may be due to leaks and inadequate ventilation

@Austin,

I can't diagnose the rot and mold damage on the soffits of your house reliably from a single photo, but I suspect but you have a combination of leaks and no ventilation.

Do you see that damage on both sides of your home or is a more damage on the side that is shaded?

You want to inspect your roof for leaks especially at the eaves, and it's evident that you have no roof ventilation installed.

So it's also worth inspecting in your attic for signs of leaks into the attic and for the extent of moisture and mold that might be in that area.

If you use the on Page search box to search this website for

Roof ventilation specifications

you will see good design details to improve the ventilation system.

On 2021-12-15 by Austin

I have this rot in the sophets of my home, how can I tell what caused this and should I be worried about the structure of my home.

soffit damage (C) InspectApedia.com Austin

On 2021-03-29 by danjoefriedman (mod)

@Claudia, I don't have a size scale in your photo so I can't be sure but It looks to me like spider poop and very small insect holes that could be characteristic of old powder post beetles damage.

On 2021-03-28 by Claudia

Hi. Got a bad problem at my house. We had been figuring it was something in the paint maybe ftom 5 years ago but now I’ve found the same thing occurring in the eucalyptus wood glider on our screened porch.

These minuscule holes with a minuscule white drip beneath them are in the millions all over our cedar shakes house and now in a totally different wood on the glider. Terminix treats for wolf spiders and they can’t figure it out.

insect holes and droppings (C) InspectApedia.com Claudia

On 2021-03-13 - by (mod) - bagworm moth larvae cases

Examples of bagworm moth larvae (Davis 1964) at InspectApedia.comMichael

The illustration shows some examples of some of the larval cases of this genera, (Davis 1964)

@Michael, Thank you; these bagworm moth casing photos will be helpful to other readers, as these insects are ubiquitous, particularly where evergreens are nearby.

Some useful bagworm moth research:

On 2021-03-13 by Michael: encasements of bagworm moths - Psyche caste

@Michael,

Bagworm moth casing found on building exteriors (as well as other locations in the outdoors (C) InspectApedia.com Michael

(2) additional photos of Bagworm Moth casings attached to exterior cedar siding

Bagworm moth casing found on building exteriors (as well as other locations in the outdoors (C) InspectApedia.com Michael

On 2021-03-12 - by (mod) - encasements of bagworm moths - Psyche caste

thank you Michael, that feedback will be helpful to other readers. If you have additional photos including a quite sharp close up that would be most helpful.

On 2021-03-12 by Michael

Long delay on responding back but after putting the question out on the town list serv - several people chimed in - the attachments are the encasements of bagworm moths - Psyche caste. The larvae make cocoons out of collected debris - twigs, plants, rubbish spun with silk - hence the twig or stick-like appearance.

They embed themselves only so far as the exterior stain on the cedar siding w/ no burrowing beyond the stain - although it may be my pulling the cocoon off pulls a spot of stain away however they adhere to the surface. The initial confusion was that at passing glance they look like wood being burrowed from within.

On 2021-03-08 - by (mod) - mud and mold on interior wood structure: previous exposure to weather?

@Patty, I see what looks like mud, thick on the sides of joists and on subflooring, with some straight edges marked in the mud suggesting that an assembly was left outdoors and exposed to weather - water damage, and a bit of fungal growth - fine black growth patterns on the edges of the doubled blocking and joists. .

On 2021-03-08 by Patty

We live in Southeastern Wisconsin - - Does anyone know what might be causing this damage to the rafter in my basement?

On 2021-01-05 - by (mod) - insect larvae or plant seeds adhered to building exterior?

Michael

I'll bet a 6-pack of Castle Danger beer that if you take a couple of those plant-fibre like structures to your local county farm and home center or environmental center they can identify that;

I've seen those same things but from just your photo am not sure if it's insect or plant.

I'll do some further research too but let me know what you're told.

In either case these "insects" appear to do no more than cosmetic damage to wood or other exterior surfaces.

On 2021-01-05 by Michael

Based in Lincoln, MA outside of Boston, we live in a 1969 designed/built cedar sided house.In removing the original 1969 AC unit which was butted up against the exterior siding, the removal exposed a small rectangular section of original unfinished cedar that has never been finished or stained.

Wood damage was seen a short while after removing the AC but was thought to be mice damage from mice exiting the house above an entry point we screened and foamed up. However - I just noticed small bundles of thread-like material - wood? - hanging off other areas of the house.

These are few in number, widely spaced, never in any pattern or density - each seems to be a 'one-off'. They also appear on different exposures of the house - N and E and on a separate detached garage structure- also w/ cedar vertical siding.

There is no evidence of sawdust or piles of shavings beneath any hole, no lateral damage evident and although we do have woodpeckers in the woods around us, we have not had or seen them attacking the house. I have not found any similar images on-line so am stumped.

Any insight or suggestions as to the cause - and treatment - and who I might contact for help in the area would be appreciated. Many thanks - Michael



Above & below: unidentified gray fibrous insect or plant material found on the exterior of buildings.

On 2020-08-22 by Al Bennett

I am seeing patches of surface damage to old cedar fence boards that were used to line the interior of a rustic cabin. There is a layer formed on the surface that is easily removed and the wood below looks fresh. The layer contains some grit. I would like to know what causes this and how to control it.

On 2020-04-16 - by (mod) -

Pam

Please try the

Add image

Button and I can comment further.

On 2020-04-16 by Pam

I just noticed some damage to a wood beam running along the ceiling of my apartment. Is this bug damage? Does anyone know if it is and what kind of bug? Thanks!

On 2020-02-17 - by (mod) - insect damaged siding or fencing? Sap?


Steve
That's certainly interesting.

It looks like old insect damage; I can't say if the white material is sap or insect frass. The pattern and location is not characteristic of termites, but it'd be useful to poke at or pick out a bit of the white material to examine its consistency.

What I want to know is if the material is comprised of

- sawdust
- sap
- larvae
- old paint
- something else

it would also help to know

- country and city location
- type of wood (species)
- how long that wood (fencing) has been in place
- whether the wood was salvaged from some prior use

On 2020-02-17 by Steve

What caused this? [Photo above3]

 




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On 2023-04-12 by InspectApedia Publisher - size of holes indicate carpenter ants

@Chuck,

Please see our complete reply now moved to

CARPENTER ANTS

On 2023-04-12 by Chuck

Hello, I inspected a detached garage today that had visible wood damage from the outside. The owner let me open the damaged area by pushing it in (and it easily crumbled) to see if any insects were visible inside.

When I opened the area I saw the damaged wood (see attached picture) with a number of these little round oval dark brown to blackish things inside (see circled area on picture). I saw no visible pests but a number of these oval things. You can tell some sort of wood destroying insect has been damaging the wood.

The owner said he started noticing the damaged wood for approx 6 months but just now decided to have it looked at. He said the damage has grown significantly in that time and is continuing to grow. I ruled out subterranean termites due to the holes being too large. Any help identifying appreciated.

carpenter ant damage in garage (C) InspectApedia.com Chuck

On 2023-04-05 by InspectApedia Publisher

@Beth,

Please see our complete reply now moved to

CARPENTER ANTS

On 2023-04-05 by Beth

Can you tell me what kind of ant this is ? We mostly see the ants in our living room but sometimes they come in bathroom, kitchen, or bedroom.


On 2022-10-15 by InspectApedia (Editor)

@oboy,

Looks like carpenter ant damage (or another insect) probably from before the wood was milled.

Please see our complete reply now moved to

CARPENTER ANTS

On 2022-10-15 by oboy

What Does this looks like? Bug ID

carpenter ant holes (C) InspectApedia.com Oboy



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