Oh Crap Calsimine!!!

Two weeks ago I traveled to Halletsville Texas to look at a restoration project we are starting. The beautiful Romanesque Revival styled Lavaca County Courthouse was built in 1897 with plans drawn by Eugene T. Heiner.

The restoration program and plans was created by The Williams Company. I’ve worked on quite a few projects with the Williams company and Kim Williams and his associates are well versed in all aspects of restoration and very professional.

The construction manager is Weaver & Jacobs Constructors Inc. of Cureo Texas, While they have not done a lot of restoration projects,  I’m impressed so far with their approach and the project is proceeding very well. In fact it is 5 weeks ahead of schedule which is almost unheard of on these types of projects.

While examining the plaster surfaces on the project I found an issue that has become all too common in restoration. (See Video) the walls at some point were painted with calcimine paint. The English name for this paint is distemper. It is made from finely ground Calcium Carbonate (calk) mixed with a glue binder. Not to be confused with lime paint which was created using calcium oxide or quick lime. The calcimine paints were designed to be mixed with a binder or glue while Lime paints were mixed with water. Calcimine paints mixed with water would not ever get hard but would seem fine at first. According to an old Scottish painter friend of mine Calcimine paints were used in the trades mostly to paint ornate plaster moldings. This allowed them to remove the paint every easily the next time they wanted to paint the moldings and the paint would not build up on the surfaces hiding the intricate detail. However as the practice continued painters would start using the calcimine paint mixed in water to paint the flat walls and ceilings it was much cheaper to use water than glue and cheaper than lime paint which is what traditionally would have been used on the big flat walls and ceilings. Some might have used a little glue in the mix.  Since it was cheap and looked good after the project was complete the practice continued.

Enter oil based paints. Now painters were used to just painting over the surfaces without removing the old paints a practice that was common with painters used to working with calcimine paint. Now you have a film of paint that is somewhat adhered to the calk paint. Layer after layer of paint applied as the building got redecorated. But if any water got back down into the chalky paint it would quickly release. Once it started to release the paint would peel away and because one understood what this chalky surface was sometimes the plaster surface was blamed. Painters said that the old plaster was deteriorating and they could paint the surface. So drywall was installed over the plaster.

That was probably what happened here in Hallettsville. The original plaster surface is fine though not as hard as modern plasters it is in good shape. We just need to remove the calcimine paint repair the holes where the sheetrock was attached to the surface and get this grand old building back to its original beauty.