Preserving Ornate Ceilings

We just moved into a home with a beautiful ceiling and we're wondering how best to paint and preserve it. How can we prevent the ceiling from losing its detail during the painting process? One Web site we found suggested stripping off the old paint. Is this really possible? And how can I find someone to do it? I don't trust myself on this one!

Your caution is understandable. Most of us are familiar with gypsum drywall, not ornamental plaster, and this ceiling is an architectural detail well worth preserving.

Before the advent of gypsum drywall, plaster was a standard interior finish. In many parts of the country plastering is now a specialized craft that to most of us seems as mysterious as quantum physics.

For help, I turned to Noelle and Peter Lord, a Maine couple whose company, Old House C.P.R, deals with a variety of old house issues and especially plaster (you can visit them at their web site, oldhousecpr.com).

First, find out what the pattern is made from. According to the Lords, the ornamentation in your ceiling might be one of two things, each of which reacts very differently to paint strippers.

In some cases, patterns were created by embossing the plaster with a compound called "whiting," which is a mix of linseed oil and lime. If the pattern is only slightly raised from the surrounding surface, it could very well be this. Because of its linseed oil content, whiting can pick up a strong yellow hue over time.

The problem is that many paint strippers will dissolve whiting, clearly something you want to avoid. If, on the other hand, the pattern is finish plaster a solvent-based stripper can be used to remove paint safely.

The Lords would start by testing the surface. Choose an area of about 1 square foot in a not-so-obvious place on the ceiling and use a gentle paint stripper such as Citrus Strip. If the surface starts to dissolve, it's most likely whiting, not finish plaster. Cease and desist immediately. But if there's no apparent effect on the integrity of the ceiling, the stripper shouldn't do the surface any harm.

Calcimine, the bane of many old plaster surfaces, is another potential complication. Calcimine is a mixture of powdered chalk, glue and water that was routinely used to whiten ceilings. A single coat can be washed off with water, but a build up of many coats can be tough to get off. The problem is made worse when calcimine is painted over with latex or oil paint.

If paint is peeling, it may be a sign that calcimine is interfering with the bond. Stripping it off with steam is a possibility. But as the Lords advise, this isn't a job for beginners.

This may indeed be time for a pro. If stripping the surface sounds too complicated, and if the surface doesn't show any signs of peeling, you may just want to clean it and repaint. Try a gentle cleaner (the Lords recommend Dirtex).

Spraying on a new coat of paint, rather than using a roller or a brush, will result in a thinner, more even coat that's less likely to obscure the details.

Considering the job complexity, no one could blame you for picking up the phone and calling a plaster pro. You want a specialist, someone whose work regularly includes historic homes and restoration.

Ask around, and check the Yellow Pages and Internet directories such as buildingtradesdir.com. When you find some candidates, the usual cautions should apply: make sure they have experience in plaster restoration and check their references.