Corwithe & Vane, Timber Pest Conservators · Partridge Hollow, Old Gaunt & the Mincing Lane historic district · Est. 1981
The frame has stood two hundred years. Ours is the third hundred.
Corwithe & Vane treats timber pests in old structures the way a conservator treats a painting — from the evidence, with the least intervention that holds. Powderpost in the sill, drywood termites in the raking, deathwatch in the sash — each wants a different hand, never a spray calendar. Borates into the galleries, dust into the voids, the moisture source named in writing.
940 historic structures served since 1981 · the oldest frame, 1784 · members of the district preservation review board on retainer
We treat the house the way a conservator treats a painting — from the evidence, never the calendar, and with a hand that can be undone.
What we do
The register: three timber pests
The powderpost beetle — flour on the sill
Lyctid frass is fine as baking flour, and it means the beetle’s larvae are digesting the starch out of your hardwood sill from the inside. The conservator’s course: a borate glycol solution drawn into the member itself — the wood drinks it, the larvae cannot — with the surface reading unchanged afterward. We name the moisture source that let the eggs take, because powderpost is a symptom with a humidity problem attached, and the note in your file says which one.
The drywood termite — no mud tubes about it
Drywood colonies live inside the member they eat, needing no ground and no tube — you learn of them by the six-sided pellets in the attic dust or the swarm on a still September afternoon. Where the colony is bounded, we open the gallery, inject it directly and close the wood; where the framing is riddled, we will say the word fumigation out loud and write the referral honestly, because a fake targeted treatment is the one thing a historic frame cannot afford.
The deathwatch & the old sash
The tapping you hear on a quiet spring night in Old Gaunt is a beetle looking for a mate inside your window frame — romantic, and structurally beside the point. The course runs a night survey with a red lens and a moisture meter on every sash: galleries dusted through the existing checks, the putty and the paint made sound again, and the downspout that has been feeding the bay window since the Kennedy administration named in the report.
The conservator’s warranty
Five years on every timber member we treat — borate, dust, gallery and seal — and the file to prove what was done, where, and with what. If activity returns inside the term, the member is re-treated free and the file amended, not reopened. The paper outlasts the practice and is meant to.
The practice
Why the district keeps us on retainer
Preservation boards do not fear insects; they fear interventions. Tenting a 1790s frame for one colony of drywood termites, or sandblasting a sill for a beetle that a borate would have finished — those are the losses a district cannot undo. Corwithe & Vane opened in 1981 to be the other phone call: the survey that proves the extent, the treatment aimed at the member, the chemistry registered for use in historic structures, and a written record that makes the next conservator’s work easier instead of impossible.
The practice, in figures
How a conservation runs
Four movements, in order, every time.
Survey
Sounding every suspect member, moisture readings at the sills, a borescope into the checks, and frass under the glass — the diagnosis before the treatment, always.
Determine
The species named in writing, common and Latin, with the extent mapped on the elevations. The house file opens here, and it never closes.
Place
Borates drawn into the galleries, desiccant dust sealed into the voids, the moisture source quoted for repair. Nothing broadcast, nothing a tour group would ever see.
File
A bound page for the house’s record: what was found, what was placed, the re-entry interval, the warranty term. Boards, insurers and buyers read the same page.
The district review board expected a fight and got a survey. Corwithe mapped the drywood colony to four members of the east elevation, treated them in place with borate, and the painted surface never showed a scar. The house file is now part of our board minutes.
Our 1784 frame had powderpost in two sills and a beetle seller — sorry, a beetle “specialist” — quoting a tent. Corwithe drew the borate into the members instead, named the downspout that had been feeding the corner for decades, and the frass stopped inside a season. The house looks exactly as it did. That was the brief.
I curate a house museum where the deathwatch beetles were, honestly, part of the charm until they weren’t. Night survey, red lens, dust in the checks, sound putty — and a report the insurance carrier accepted without a single follow-up question. The re-entry notice said forty-five minutes and the morning tour ran on time.
Will borates harm old-growth wood?
No — a water-glycol borate is registered for exactly this use and has been the preservation standard for decades. The solution is drawn into the member, fixes in the wood, and leaves paint, patina and profile untouched. What it does not leave is a larva: the wood becomes inedible to the beetle and stays that way for the life of the member.
When is fumigation honestly necessary?
Rarely, and we say so plainly when it is: a frame riddled through with drywood colonies beyond targeted treatment is better tented once than patched forever. In that case we write the referral, review the fumigator’s plan against the district’s requirements, and return for the borate follow-up that keeps the next colony out. Honesty about extent is the whole practice.
Can you work around occupants and tours?
Continuously. Placements are voids and galleries — re-entry is forty-five minutes after the dust sets — and noisy stages like the night survey are scheduled around the docents. A house museum on the files has never lost a tour day to us, and the morning after a placement smells like a house museum, not a spray rig.
What is in the house file, exactly?
The determination with species and Latin name, the elevation map with every treated member, products by name and registration number, moisture readings and their sources, the re-entry intervals, and the warranty terms — bound, paginated, and updated on every visit. Insurers read it, boards read it, and at sale it transfers with the deed. Two of our files have outlived their houses’ restorations and both were cited in the plaques.
Do you handle modern buildings too?
When the insect is a timber insect, the method does not care about the century. We treat post-and-beam shops, barn conversions and the occasional timber-framed restaurant with the same survey-to-file discipline — the modern ones just come with fewer committee meetings attached.
Before you write
Correspondence received
The five questions the desk answers most, kept in the order they arrive. Anything further, write the desk — letters by post still reach us fastest of all.
Surveys booked within the fortnight · written determinations inside three days of the walk · (555) 043-5246 · desk@corwithevane.example
Write the desk
The town, the rough age of the structure, and what has been seen — frass in a baggie or pellets in an envelope answer half the survey before the van rolls. Determinations are bound whether or not a conservation follows. The desk answers (555) 043-5246, or desk@corwithevane.example.