# Bell Tower Woodworm Treatment, St John's Parish Church, Moira

Case study: insecticidal woodworm treatment to the bell tower timbers at St John's Parish Church, Moira — a Georgian church dating from 1722.

St John's Parish Church stands on the Main Street in Moira, opposite the old Demesne, and has done since the parish was founded in 1721. The Rawdon family funded much of the original build, the Hill family gave the land, and the tower has carried a bell and a copper-clad spire since the original slate steeple was blown down in a storm in 1884. Three hundred years of continuous use is exactly the kind of history that makes a bell tower worth protecting properly.

![Radication Ltd vans outside St John's Parish Church, Moira, during woodworm treatment to the bell tower timbers](/blog-images/radication-ltd-vans-outside-st-johns-parish-church-moira-during-woodworm-treatment-to-the-bell-tower-timbers-d9ff6271.webp)

## Why a bell tower is the hardest case for woodworm

A church tower is a different problem to a roof void, and three things set it apart.

**It is a working structure, not a static one.** A bell frame carries load and movement every time the bell swings or the clock strikes. Beetle attack that would just be cosmetic in a static rafter becomes a structural question in timber that is designed to flex and take repeated stress.

**Access is difficult and infrequent.** Ladders, trapdoors and awkward floors mean a bell chamber does not get looked at the way a loft does. Infestation can run unchecked for a long time between visits, and by the time anyone is up there for another reason, the damage has often had years to establish itself.

**The timber is original and, in places, irreplaceable.** Bell frames, louvre boards and floor joists in a tower of this age are frequently the same members installed when the tower was built or last repaired. Removing and replacing them is a bigger undertaking than treating them, and on a listed or historic building it is not always a straightforward option either.

## What we did

We carried out **insecticidal treatment to the bell tower timbers**, using our low-odour, water-based microemulsion insecticide, applied by spray to the bell frame, floor joists and access ladders within the tower. For the detail on why we favour a microemulsion, and where boron is the better answer instead, see [boron or microemulsion](https://radication.co.uk/blog/boron-or-microemulsion-woodworm-treatment).

The choice of product mattered here for the same reason it mattered at [Dobbins Inn](https://radication.co.uk/blog/roof-timber-treatment-carrickfergus): the building stays in use. Services, weddings, funerals and the ringing of the bell all continue on the normal parish schedule. A non-flammable, low-odour treatment meant we did not need to close the tower or the church to carry out the work, and there was no lingering solvent smell to manage in an occupied building. The treatment kills any beetle already active in the timber and leaves a protective residue to guard against reinfestation.

## Minimum intervention, deliberately

As with any historic building, the aim was to treat and retain, not to strip out and replace. A few principles guided the job:

- **Old flight holes are not automatically a problem.** Dormant damage from years or decades ago does not need timber removed on sight. The question that matters is whether the infestation is still active — see [is my woodworm still active](https://radication.co.uk/blog/is-my-woodworm-still-active).
- **The bell frame gets engineering judgement, not a glance.** A timber that looks superficially sound can be compromised at a bearing point; a timber that looks heavily bored can still be structurally adequate. Where there was any doubt about load-bearing sections of the frame, that was a survey question, not a treatment one.
- **Ventilation in the louvres was checked, not just the timber.** A bell chamber is meant to be an open, airy space by design — that is what the louvres are for. Keeping that airflow intact matters as much as the insecticidal treatment itself in keeping the timber dry and unattractive to beetle in future.

## If you look after a church or historic tower

- **Get someone up into the bell chamber periodically**, not just when the bell needs attention. Fresh, pale-edged holes and fine powdery frass on the floor are the signs to look for.
- **Don't let the louvres get blocked or sealed.** Bird proofing and repairs sometimes reduce airflow as a side effect — check it hasn't after any works.
- **Treat access difficulty as a reason to inspect more often, not less.** A hard-to-reach space is exactly where attack goes unnoticed longest.
- **Favour retention over replacement** for original bell frame and floor timbers, and ask any contractor to justify removal rather than assume it.
- **Check accreditation.** We are Property Care Association members and [TrustMark registered](https://www.trustmark.org.uk/firms/Radication-Ltd-476116/), so the work is carried out to a specification and guaranteed — see our [accreditations](https://radication.co.uk/about-us).

## Project details

|  |  |
| --- | --- |
| **Building** | St John's Parish Church, Georgian church built 1722–1723 |
| **Location** | Moira, County Down |
| **Work completed** | 2025 |
| **Services** | [Woodworm treatment](https://radication.co.uk/services/woodworm-treatment) |

We have treated timber in historic churches and parish buildings across Northern Ireland since 1967. See our work at [First Ballymena Presbyterian Church](https://radication.co.uk/blog/first-ballymena-presbyterian-church-est-1627) and [Bushmills Distillery](https://radication.co.uk/blog/bushmills-distillery-bushmills), what we cover around [Lisburn](https://radication.co.uk/areas/lisburn), or ring **028 9061 8343** to arrange a survey.