Still waiting to exchange contracts, so here's a bit about my knowledge and experience of old buildings:
I once went on a one day course with the Society for the Preservation of Ancient Buildings (SPAB) called "Faith in Maintenance". This excellent course was aimed at people who were elected as churchwardens and suddenly found themselves responsible for possibly a massive 800-year old Grade I listed church, without an idea of how to look after it.
The major lesson from the course was "control the water" which goes on/in/down roof, gutters, downpipes, drains etc. If you do this successfully, we were told, you will do four-fifths of the job. Essentially, prolonged exposure to water means serious damage to an old building, and a high repair cost. The old proverb about a "stitch in time saves nine" is very relevant but understates the saving as spending £500 on roof maintenance every year may well save a capital expenditure of a thousand times that in a few years time.
The second lesson was to never use inappropriate materials; I shall
probably go on about this at length in this blog, but principally do not mix modern materials (cement/gypsum plaster) with old materials (lime mortar/plaster/render) because it doesn't work! You have to understand how the building was intended to work with dampness and go with it, not fight against it. A modern house sits on a waterproof membrane and works on keeping all moisture out by using impermeable materials, whereas a building made with lime mortar/plaster does not expect to be bone dry all the time (but see lesson one above!). Instead, it expects there to be draughts, and manages moisture by allowing it to evaporate through the mortar in the walls. Replacing the lime mortar with cement means that the moisture goes though the stone or brick instead, causing damage such as delamination of the face of the stone or brick. Covering a wall with (impervious) gypsum plaster instead of lime plaster means that moisture will be retained inside the house; it has to go somewhere so it will form on the inside of the wall or run down windows excessively, etc.
So don't mix vinyl paint, ribbon pointing or injected chemical damp-proof courses with lime walls. Basically, if you want a modern house then buy one, don't try to convert an old one.
My experience with a 320 year old church
In a sense I was lucky as the Grade II* listed church I looked after for five years only dated from c.1685, apart from the late mediaeval tower base. In the church I found many examples of poor repairs and maintenance:
- cast iron downpipes replaced with black plastic
- earth/leaves/twigs allowed to pile up outside a wall, causing dampness and cold inside (see right)
- gypsum plaster repairs on lime plaster walls (it really does fall off)
- modern vinyl paints used on walls and stonework
- lime plaster falling off because of prolonged flow of rainwater due to a blocked gulley on the roof
- extensive use of a cement skim (about one-eighth of an inch) over walls, window cills and stonework, presumably done in some cases to tidy up the appearance of these items
- water pouring down inside the walls of the tower due to the internal roof not draining. This was caused by excessive pigeon guano (see right, lower),
which itself was there partly because a previous rector had placed nesting boxes up there!
- damaged window panes not replaced - when these were done, I discovered that one pane, which had a sheet of clear plastic over the hole, had been missing for over 20 years; the annual maintenance had been to replace the sellotape holding the plastic!
- poor workmanship by roofing contractors, who had fitted new slates and copper valleys, but had bodged the woodwork around the clerestory windows (using untreated one-inch plywood in one place)
- the many church doors had been repainted without permission or skill - the old royal blue was now covered by grey paint which looked like the stuff used to paint battleships, and it was peeling as they had not even sanded down the blue to provide a key
The same roof window, before and after.
The same roof dormer door, before and after.
Most of these matters were rectified in my time, together with many more, but we were very busy and some remain... You could sum it up by saying that the church building was not loved, and old buildings need to be loved if they are to survive.
