Using the Right Materials to Repair Your Older Home
In order to choose the right materials it’s important to understand how your house was built.
Buildings of traditional construction (generally those built before 1914) used soft weak permeable (or 'breathable') materials such as lime mortars. Later modern construction, on the other hand, uses strong impervious materials such as cement and concrete. If you use modern materials with traditional construction you may just be causing more damage by trapping moisture and reducing permeability.
If you want to make repairs to your home you may need permission and should seek advice, especially if your home is listed or in a conservation area (see Who Do I Contact?).
When selecting new materials for like-for-like repairs these should match the original materials as closely as possible. They need to match not only in appearance but also in physical properties so that they react the same way over time.
Identical materials used for repair can initially present a stark new contrast against the existing building fabric. But these will weather in sympathetically over time, so it’s better to do this than try and match the weathering by using salvaged materials. The stripping of disused buildings to supply a demand for salvaged materials should not be encouraged.
If it’s not possible to source identical materials then you should try to use the most similar available. Failing this you could approach the repair in a different way.
The use of modern materials can sometimes be a solution if it means ultimately retaining more original historic material. For instance, the use of some stainless steel in repairing a historic roof might allow you to keep more of the original timber than a traditional repair.
All repairs, however they are carried out, should avoid the need for intensive maintenance as this is likely to be difficult to sustain. Previous repairs should be treated with respect and shouldn't need to be touched unless they're failing.
Sourcing Materials/Specialist Suppliers
There are now a wide variety of suppliers of many different types of material for traditional construction: lime for mortars; hair for plasters; clay roofing tiles; and wattle for infill panels in timber-framed buildings. Details can be found in specialist directories such as The Building Conservation Directory.
Your local conservation officer may be able to help in sourcing a material that is particular to your area, such as a type of brick that was produced locally, or a particular type of stone (see the Strategic Stone Study).