Renovation – Why is 1919 important?


Hi everyone…welsh hall (2)

To the right is a massive Georgian hall in the wilds of Wales – there is not a skerrick of modern material in the place – it has survived untouched since it was built.  Lime render, lime plaster everywhere.  It was full of holes, water running down the stairs – but amazingly, because it is so breathable, surviving almost intact.  The glass in the bay windows is actually curved! It’s now being sensitively restored.

So because there are many properties similar to the above, I thought I’d start my blogs with a few words about ‘Old Buildings’. We all talk about Renovation, Restoration, Conservation.. they are buzz words at the moment – so what do they really mean?

An old building used to be defined as one built before 1919. Heaven knows who decided that 1920 was Modern, and 1919 was Old. A bit daft if you ask me – there’s no real definition to it, and it’s not practical at all. Recently, I was talking to friends in English Heritage about it, and we floated the idea of a new, and better way of defining an ‘Old Building’. It’s done the rounds a bit – but now we can talk about ‘Old’ or ‘Historic’ in a totally different way.

This is what the definition of an ‘Old Building’ is now:

“An old, or historic building is defined as a structure built using breathable materials and having solid walls.”

What are solid walls?

They can be stone – a rubble stone thatched cottage, a huge Palladian mansion built with stone blocks, a Cornish Engine House. They can be brick – a Victorian terraced cottage, a Georgian townhouse, a Staffordshire brick farmhouse. All of these would use lime mortar to hold them together. The walls of a timber framed cottage are solid: Infill panels, within solid timber framing. Lime plaster and render would cover the walls, limewash paints would finish them.

So what’s the significance of this? Well for a start, it talks about materials. It talks about brick, stone, lime mortar, lime plaster and render, oak framing, wattle and daub. There’s a bit of a pattern developing here – breathability. All these materials are open, porous materials that allow air and moisture to diffuse freely through them. That means that they can get wet, and dry out quickly.

Old buildings have been around for a long time – there are plenty which are 450 years old, and still going well.  So why is it that everyone thinks old houses are cold, damp, draughty – and should be knocked down and replaced with nice shiny dogboxes?  Why is it that row, after row of beautiful old Victorian townhouses – with their lovely high ceilings, fireplaces, and tiny cobbled back yards, being knocked down in city centres?

There is a simple answer:  It’s all in the breathability…

As long as these traditional materials are able to stay dry, they will.  Take a look outside when it’s raining – everything is wet, right?  It stops raining, and the pavement dries out. The roads dry.  The soil dries out again.  A quick summer shower, and an hour later all the water is gone.  If air can get to an old house, the same thing happens – it dries out.  Old houses are inherently dry – the materials they are built with ensure that.

The problem, dear Watson, is modern impermeable building materials.  Enter our friends gypsum plaster and cement,  plastic paints,  modern ‘sealants’ – silicone, acrylic, rubber, mastic.  It’s a bit like taking your house for a cross country run in a plastic mac.  It sweats, it gets sopping wet, and because it’s covered in cement, gypsum plaster, and plastic paint, it cannot dry out.  So it starts to rot – literally.  Timbers get wet, brickwork becomes damp.  Plaster is hollow and flaky, paint peels.  Wet walls are cold walls, so mould and mildew start to appear.  Oh dear – now we’ve got ‘Rising Damp’ and the damp wallies appear with their injection damp proofing and toxic chemicals.

The solution is so simple, so elegant – and if you are renovating a property, cost effective too!

Just get rid of modern materials.  Remove the last 50 years worth of gypsum plaster, cement pointing, damp proofing plasters, modern paints and acrylic wallpaper.

Underneath will be a beautiful old building, just waiting to dry out – to be loved once more.

In my next blog, we’ll start to explore some of the materials, and their effects.  Some of the symptoms of ‘damp’ and what they really are.  We’ll examine the right materials to use for older houses. There is more understanding of building materials these days, more research.  Thankfully you can now buy traditional materials easily and cheaply – lime mortars and plasters, sheepwool insulation – and the skills to use them are becoming commonplace.

Till next time…. happy house hunting!