An older roof was built to a different logic. It was designed to breathe, to move a little, and to be maintained rather than sealed. Applying modern assumptions to it, impermeable membranes, cement where lime belongs, heavier coverings, sealants instead of dressed lead, is how a great many period roofs have been quietly damaged over the last fifty years.
Breathability matters more than you would think
Solid-wall, lime-built properties handle moisture by letting it move through and evaporate. Wrap a roof of that construction in impermeable materials and the moisture has nowhere to go, so it collects in the timbers instead. On re-roofs of older buildings we specify breathable membranes and keep ventilation paths clear rather than sealing everything up.
Details that belong on an old roof
The right details on a period building are usually the traditional ones, and they perform well when they are done properly rather than quickly.
- Dressed lead flashings and soakers instead of cement fillets
- Bedded or cloaked verges rather than plastic dry verge units
- Reclaimed pantiles or matched slate rather than modern substitutes
- Appropriate mortar mixes rather than a hard, brittle cement
- Salvage and re-lay of the existing covering wherever it is sound
What we usually find when the covering comes off
Timbers of irregular size, sometimes reused from an earlier building. Battens riven rather than sawn. Historic repairs, occasionally very good ones. Rafter feet that have suffered from an overflowing gutter for a century. None of that is alarming in itself, but it does mean a period re-roof cannot be quoted as if it were a modern estate house, we allow for the unknown and agree it with you as it is uncovered.
Sympathetic does not mean fragile
A properly re-laid period roof with the original covering, new battens, a breather membrane, correct lead and clear ventilation performs to a modern standard while looking exactly as it should from the street. That is the aim: modern durability, traditional appearance, no plastic where it will be seen.
Common questions
Will you match my existing tiles?
We salvage and re-lay wherever the covering allows, and top up with matched reclaimed stock. On visible elevations that is usually the difference between a roof that looks right and one that does not.
Do I need permission to re-roof an older house?
Not usually for like-for-like on an unlisted property outside a conservation area. In a conservation area, or if the property is listed, there are constraints and we will talk you through them before quoting.
Is it worth insulating an old roof at the same time?
Often, but it needs doing in a way that does not trap moisture in a breathing structure. That is a design question, not an off-the-shelf answer, and we will not simply stuff insulation into the eaves.
Can old undersized timbers take a new covering?
They frequently can if the covering is the same weight or lighter. Going heavier is the change that needs checking properly first.