Where the floor has been constructed over an earth ‘solum’, moisture will rise towards a warmer interior. If floor boards become damp for this or any other reason, lift any linoleum or plastic covering and allow them to dry out, after checking for signs of rot.
To help prevent this problem, no covering should be stuck down on a basic timber floor and carpets with rubber backing should not be used.
Allow air to circulate by keeping floors unsealed and dry and minimise damp problems by keeping washing to a minimum, avoiding wetting the bases of walls and columns.
Do not use any wax or coatings other than linseed oil on flagstone or clay tiling.
Marble flooring should only be dust-mopped.

Timber platforms below pews may fail in places if previous cutting-out for service pipework, etc. has not been properly supported. Do not allow similar work to be done without inspecting it before the boards are replaced.

Do not use salt or sand to protect external steps from frost and ice. Both can damage vulnerable floors if carried inside.

Much damage is done by inappropriate paint and wall coverings.
Non-porous coatings concentrate moisture, cause decay of plaster and blistering of the paint surface. Any paintwork, especially anything done directly on the plaster, must be breathable. Normal emulsion or gloss paint is not satisfactory.
Limewash, distemper or a clay paint should be used instead.
Treating damp by framing in with plasterboard is not a proper solution and frequently results in needless expense. Look for the source of the damp and ensure that it can escape directly or through improved ventilation.
VENTILATION is indeed the principal key to improving conditions inside your church building and keeping them pleasant.
In a building that is not continually used, permanent ventilation at a reasonable level is especially important. This must include floor vents, working windows and any fleches or other devices designed to bring in and extract air via the ceiling.

A balance has to be struck between keeping insects and weather out and dispersing moisture that builds up inside the church. Opening a few windows before each service and sealing up the building afterwards is not sufficient. An old building should not smell damp but a poorly-ventilated and ill-maintained one will surely do so.

Memorials, Wall Plaques and Stained Glass should be protected from impact during building work and anything not stored away that is fragile or valuable should be recorded.
Organs are vulnerable to dust and must be carefully protected under dust proof sheeting when such conditions are expected. They can also be made unplayable if water gets inside and the organist should be alert to possible drips from water penetration overhead.
Cleaners can be important in spotting early signs of problems. Ask them to report without fail any fallen plaster, stone or wood dust or other unusual deposits on floors or furnishings. Then make sure that the source is quickly traced and assessed for suitable action.