Friday, 15 February 2013

Cleaning and Restoring of Cornice’s and Ceiling Roses

Unfortunately the cleaning and restoring of Victorian Cornices and Roses should not be attempted by the unqualified. I have seen amateur restoration that has been done very well, but I see more disasters and, as is always the way, it costs more to correct the problems than it would have cost to employ a professional originally. Even amateurs best results have fallen at the last hurdle: with the end result painted using a modern paint – a very big no no, or it’s later disintegration due to the over application of chemicals – or even just water, that has left them in a weak and stained condition. DON’T DO IT!
The cleaning of decorative plasterwork is both slow and careful work. There is no quick method, it must be done by an experienced hand. For this reason the job can be costly!

Employing a plasterer
The chap who skimmed your bathroom beautifully may be just the man for the job, but don’t bank on it. Plasterers who are qualified through the City and Guilds training schemes to a level 2 are unlikely to have learnt anything but the most basic of techniques. They could probably mount new cornices etc but are unlikely to have any knowledge about restoration of old plaster work. The City and Guilds Level 2 Advanced does cover the making and mounting of decorative plaster and  indicates a basic ability. Someone with the City and Guilds Level 3 in Decorative Plasterwork would be well qualified for the job. Don’t dismiss a foreigner plasterer either: the training in many European countries is as good as our own and they use the same techniques and materials. Of any plasterer, merely try to ensure that they are qualified and experienced. Employing a specialist – either a firm or a sole trader, whos work comes recommended would hopefully guarantee an excellent finish.
This being said the ‘restoration’ of Victorian plaster work is relatively straight forward. The loss of detail that often prompts the desire to have it cleaned is the build up of paint. It is the chemistry of paint, the method of manufacture and the materials used, that needs to be understood.

The Background
The 19th C. development of fibrous plasterwork* and the introduction of gelatine and later rubber/silicon moulds, allowed the “mass” production of cornices and roses, cast or run in a workshop and then mounted in a home. It is for this reason that so many middle and upper middles class homes of this date have decorative mouldings.
Previously only the very rich with bespoke houses could afford a decorated ceiling. (The middle classes made do with a simple run cornice) This decorative plaster work had been done by hand, either shaping details on a bench or moulding directly onto a ceiling or wall. The materials used prior to the 19C had been lime based mixes with a great number of additional ingredients, from beer to blood! as well as plaster. [For this reason any restoration of a building dated earlier than the 19th C.MUST be done by a properly trained Restoration plasterer].
Victorian cornices and roses were chosen from pattern books. There were a great number to choose from and many of the pattern books can still be found. This ‘mass production’ was seen as a debasement of the plasterers art and much resisted by the Arts & Crafts movement of the day. Ceiling roses were a new development to replace earlier more extensive ceiling decoration, they were considered an abomination!
*Fibrous Plasterwork: The fibrous cornices and roses of the 19th C. were made with Gypsum plaster (often known as Plaster of Paris). They are normally quite thin in cross section and are backed with an open weaved hessian sacking – called scrim. Deep and detailed work may also contain wooden battens to further strengthen it. Linier cornices were often run on a bench in the workshop. These were produced in lengths of approx. 2m, dried and transported to a site and screwed and/or glued to the ceiling/wall. Enriched Cornices had additional decoration involved: Acanthus leaves, corbels, bosses, flowers, fruit and swags, the variations were endless, but the patterns actually ‘repeated’ regularly. Even the most complex form, when studied carefully shows a repeat. Thus it was cast in moulds as a single ‘repeat’ normally about 1/2m (approx.) in length. A third possibility is a combination of linier cornice with additional enrichments attached over the top. These are normally the most complex, largest and ‘deepest’.
The same goes for roses: A simple linier ring, a complete rose cast as one item or a linier ring with additional enrichment, often with ¼ section repeats. There were also additional outer enriched rings and pendants that could hide the chain used to hold up the light (candles, gas or electric)

A Note on Corners
Early cornices were run in situ and then enriched by hand, so turning a corner was an opportunity not a problem!
Georgian cornices – again run in situ but enriched with small details such as the egg and dart or running dog details [these designs were taken from the Roman and Greek ruins that had inspired the Classical style (the name given through Europe to, what we refer to as Georgian)]. These Georgian enrichments were cast (in plaster or wax moulds that preceded the gelatine mould) in very short lengths (10cm). They would then be compressed and stretched by cutting and filling or shaving before sticking in place to give a uniform looking line of detail that would then end correctly at a corner.
Fibrous Cornices: With the arrival of workshop run cornices each corner was cut and joined at the job site. This ensured the correct length and shape to provide the cornice with a uniform line along its length. This is not a problem for a linier cornice (unless the plasterer is totally inept!), but causes a problem with enriched cornice being mismatched at the corners.
There may have been no logical point where it could turn a corner in amongst to figs and the ferns. But with the sections being so short (1/2m) the plasterer to cut and fudge a design to allow it to turn at least prettily of not absolutely correctly.
[This is still a good way of checking the talents of a plasterer – weither ancient or modern: if a corner looks muddy and confused it’s been botched and the person concerned has either sacrificed good plastering for cash or is poorly trained].

Cleaning
With all types of cornice the techniques required in cleaning them is, firstly a stripping away of the old paints to reveal the original plaster. If the cornice has no sign of detachment from either the wall or ceiling, is not cracked along its length, has no signs of mould and is not soft and crumbly to the touch: it is in good condition and needs no more restorative work. Secondly, the very likely unsightly yellow and blotchy appearance of the plaster once the cornice has been cleaned is nicotine! There are methods of cleaning this, but it is difficult and the over application of cleaning fluids required to get rid of the staining can damage the plaster thus leaving you with a collapsing – but clean cornice or rose. Nicotine staining will not affect the plaster itself, so it’s best left or given a basic cleaning.
The only method of cornice construction that is likely to cause problems would be a simple linier cornice with a precast enrichment placed into it. This type of cornice can be really difficult to clean – the enrichments having been placed with no access to clean the backing cornice. Here a plasterer may advise for the enrichments to be removed and cleaned separately – if you want a perfect job and you seriously trust your plasterer then this is the best, but the most costly method. Otherwise the enrichment must be cleaned in situ and any area of the back that can be reached is also cleaned. If the plasterer doesn’t seem confident then have it cleaned this way – the cornice will look fine when finished.
Once the old paint has been removed and the plaster cleaned the whole thing must be given a couple of coats of lime wash (whitewash). It is best to leave them at this stage. A yearly repainting with lime wash will then be all that is required for the next century or so. Modern paints can be used later, when the thickness of lime wash has built up a little, although I see no real reason to bother. The problem with modern paints is that they often are too hard, once dry. The plaster is unaffected by this, but you’re setting up a real problem for the next round of cleaning (in a 100 years or so). This is also the problem found by amateur cleaners: To break through the hard surface paints force is often applied, and too much force results in passing through the soft layers of old lime wash and into the original plaster. Once the plaster has been damaged – scoured or details broken off there is a real need for a professional to come and repair all the damage. (An event I’m all too often involved in!)

Cracks and Lost Sections
Where cracking is present or the cornice/rose is coming away from the wall firstly check that the ceiling and walls are structurally sound! Cracking that carries through a cornice/rose and into the surrounding area is indicative of a problem with the structure. A cornice or rose that is coming away from the wall or ceiling may also result from a structural fault, but may also just be a loosening of the plasterwork itself. This is easily remedied by a plasterer and the materials and methods used now are almost identical to those used at the time, so no restoration dilemmas!
A cracked or damaged length can either be repaired in situ – once the cause of the fault has been rectified, or a new length of cornice can be made and put in. [This also holds for missing stretches of cornice – where a room has been subdivided or it’s layout altered in some way] A linier cornice will have its cross section copied and, were the old lengths have been cleared, a new length can be run in situ or on a bench – which ever reproduces the original production method. For enriched cornices the simplest method is to locate the points of ‘repeat’ – often this is a single length, as explained earlier, one of the lengths is removed and this is then used as a model for a new mould from which any further lengths can be produced. Again, like the run mouldings, the techniques and materials are still in current use and there is no conflict, although a plasterer may add a colour to the new pieces (it would be very light and not show through the lime wash) this is used to distinguish the new from the old work: there is no other way of telling – just showing how close modern cornice and rose’s are to their originals!

A Plaster Bank
There is a great deal of Victorian Cornice and Roses still in our Victorian housing stock. Through the years it has been ignored, removed and admired, depending on the current fashions. Currently ‘original’ featured are again in vogue and there is nothing to stop you choosing to replace missing cornices and roses- where they have been lost. Many plasterers have a range in stock and can make up new copies using the same methods and materials as the original Victorian work. Try to reproduce the same style where possible – check to see if your neighbours ceilings still have their original work. There is also a number of new designs available and bespoke designs based on your tastes are, though costly, easily manufactured. The extruded plastic cornices are also available, cheap and easy if you so prefer. Do note however that the proportions of a Cornice and Rose are extremely important, too small and they look lost, too large and they dominate the room. There is no listing issues here, although perhaps there should be!
            As previously mentioned this ‘mass production’ much despaired of by the great and the good in the Arts and Crafts movement allowed for huge numbers of cornice and rose to be produced, possibly the same ones reoccurring from John O'Groats to Lands End. But have we really taken any serious notice of them? How many variations are there? How many are actually still in existence? Are we losing them at a rate of Knots or are they still a dime a dozen? Perhaps we should take stock at some point soon and just check that we’re not taking their numbers and identities for granted! Perhaps we need a Plaster Bank? – somewhere each type could be stored and recorded, just to make sure that what we now take for granted is not lost through complacency!.

            If you wish to send a photo of your cornices and roses to me I would be interested in seeing the range still in our homes. A photo of the outside of the house and a note the town it is in would also be helpful – to give a background on the age and regional variations. I will not be using the information for any other purpose I assure you. Also if you have any questions arising from this blog, again please feel free to contact me.
           

9 comments:

  1. Hello,
    Thanks for your advice in the blog. We have recently moved in to a granite built house in Aberdeenshire which has victorian cornice in most rooms. As with most houses of this type insulation is an issue so we are planning to strip back the lath and plaster walls to the lathe and fit insulated plasterboard to the walls. The main issue with this is the orginal cornice will have to be removed and moved on to the new wall surface approx 50mm further in to room.
    Do you know if it is even possible to remove and reuse plaster cornice like this or if we would need to look at new mouldings?
    Any further advice would be much appreciated as we are really trying to make a comfortable (and more energy efficient) home while keeping the appeal of the house that we fell for in the first place.
    Thanks
    Allan Petrie

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    1. Mr Petrie
      My apologies for not getting back to you, you may have found someone else to advise you but here's a quick reply - I am now back in the land of the living and can reply quicker next time.
      Replacing cornicing:
      If the cornicing has be run on a table and then placed in position (you can tell only by cutting into the cornice - if there is a void behind it and probably a hessian or wood back to it it can be removed and replaced) the work would have to be done carefully to minimise the damage with special attention to the location of any nails or screws but it is possible. Further to this I would recommend the point of entry be at an original length end and in the centre of the wall - the corners are the hardest to get the return correct on and if you are reducing the lengths overall - due to the added insulation, you can waste a central length more easily. If the cornice was run on the wall - there is no void space then it would be unlikely you could remove it without damage. You would have to have the cornice matched and remade. Note though that many cornices have simple stepping along the bottom and top and you may be able to 'absorb' some of the stepping and keep the original cornicing.
      Replacing Roses:
      You've not mentioned the ceiling roses but just a quick note- if they were cast and place (as is most likely) then cleaning back to the plaster will also show the fixing places - nails or screw, if you undo those and then dig out the original backing plaster it is possible to remove and reattach them.
      Hope this has been helpful.

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  2. I have recently had great success removing (millions of) layers of paint from mouldings in our Victorian house using porridge. The issue I seem to have now is that the distemper has been used as a sort of filling for the detail, almost in an effort to create a flat surface to paint. I'm worried that too much scrubbing with a soft toothbrush or sponge will damage the plaster. Most of it I have managed to softly pry out with wooden tools but am having difficulty with the last stubborn bits. How would you recommend I clean this last bit? It would be a shame to damage it now. Happy to include photos if you're interested.

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  3. Yes Porridge works quite well, there are a number of pastes that work - the problem seems to be with breaking through modern paints especially oil based or waterproof ones.
    The old lime paint does tend to fill in the detail over time, it isn't deliberate, these old lime based paints tended to powder and fall away on highlights and clump in recess'. As for cleaning off the last few layers, it is difficult without looking, although I know what you mean. Try spraying slowly and copiously with water first, this can make the distemper clump together. If the distemper doesn't clump then you would have to try the opposite approach and dry out the surface as much as possible and then use a toothbrush. The main thing that you must remember is: the ceilings are high and the detail small, you will be repainting using a water soluble lime based paint and small imperfections and areas of old paint will not be visible so, whilst I'm not encouraging a slap dash attitude it is always better to leave it rather than damage it.

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  4. i have 13.5ft of original coving that needs removed and restored any idea how much this could cost per inch, foot or meter any info would be very helpful. the coving is fairly plain with a few steps. thank you

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  5. I've never lived in a place that had decorative cornices like this before. I like taking good care of things, though. I'll have to make sure I get a good plasterer for the repairs.

    Anita Mas | http://www.classicceilings.com.au/services1

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  6. We've just finished stripping and fixing the cornice in our Victorian house. Now it comes to painting it. What do we use a first layer to seal the plaster to stop stains coming through. I assume we can follow it up with a layer or two of emulsion. We will be using a spray machine.

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  7. I put up some decorative gyprock coving some years ago, a piece has now come loose and needs reattaching, can you tell me the best way to remove the plaster adhesive from the back so that it can be reattached with some fresh adhesive?

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  8. I am not sure that this is still a live blog? i am restoring the coving and cornicing in a Victorian house in Hove. I is beautiful. The paint is off (Peel Away) and I am picking out bits with wooden cocktail sticks. I am then unsure whether the plaster needs some sort of mist/primer coat, before I attempt to re-paint.

    I was also looking for any ideas of the colours that they would have been painted.

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