Monthly Archives: November 2020

Plaster repairs in the ballroom ceiling

The were a lot of holes in the ballroom ceiling and they are slowly being filled with plaster.   The walls have been damaged quite extensively and will probably need a skim, but most of the brown coloured ceiling above is in good condition apart from a few holes.   The ceiling wasn’t brown originally – the colour is from a century of tobacco smoke.

Once the plaster on the ceiling is finished I’m planning the first coat of ceiling paint to brighten up the ballroom.  I’ll do the second coat when I start decorating.

plastering-progress

The walls below can’t be completely finished until the electrician has been, but I can save time later on by making them straight and getting some plaster on them.

For base coat directly on bricks I’m using a lime render similar to the one I used outside.  It goes on much more thickly and smoothly than the white lime repair plaster which is more of a skimming plaster.    I realised while applying this bit that small bit of (modern) plaster above doesn’t line up with the door jam.  Oops – will knock that off and extend the new plaster to the original a little higher.up.

I found some rotten parquet at the bottom of this bit of this wall.   I’m hoping the rest of the concrete floor in the ballroom wasn’t laid over parquet because that would be really annoying.  But it is good to find out the main room was once finished in parquet like the snug.

base-coat

For the lath I’m using St Astier R50 Ultrafine lime plaster because I panic bought a few bags before lockdown.   It’s a skimming plaster intended to go over plaster or paint or whatever is there.   It is strong, sticky, and has a chemical set so it doesn’t crack.  It’s not exactly the right stuff for base coats as it can’t be applied thickly with any neatness.

Most of the repair plaster repair is now close to the surface and just needs finishing.   This one was a fiddle as the picture rail had been cut away.    I spliced in a a bit of picture rail recovered from the chimney and the join isn’t noticeable from the ground.

base-plaster

I’ve decided to clean the ceiling using sugar soap before the final coat of plaster on the repairs.   I had thought the paint was gloss, but it seems the gloss was just the muck on top.

Applying the soap with a sponge on the ceiling overhead and scrubbing was physically exhausting and the next day was a recovery day.  I’ve been adjusting the process  – spraying and soaking the surface, letting the sugar soap soak, then just wiping off to reduce the effort and that has sped things up.

cleaning-ceiling

The entrance vestibule now has a roof.   the ceiling of the vestibule was once part of the false ceiling.   I cut the joists back but the ceiling is weak and the vestibule made the corner of the vaulted ceiling above inaccessible by scaffold tower.

I had imagined throwing a few loft boards on top would have been a minor job but it took a whole day.  The odd shape was one thing but a lot of time was spent routing joints to make the most of what I had after I found my stock of loft board wasn’t all the same size.

The new roof provides a good platform for painting this corner of the ceiling.

entrance-roof

There is not much plaster repair in this post because I find it really boring.  It’s day after day.   I’ve been building up repair plaster to just below surface level then doing the final skim with filler and using a great big drywall sander to get things level for paint.

It’s almost finished.   I’ve tried a bit of paint over the repairs and the repairs are not noticeable.    One day more and surely I’ll be able to at least paint the ceiling.

almost-finished-filling

Some methods to repair big holes in lime plaster

The beautiful vaulted ballroom ceiling has quite a lot of big holes caused by the false ceiling, and then by plumbers and electricians fitting things above the false ceiling.    I’ve been filling the holes to get ready for plastering.

My favourite method is to use bricks.   This is a corner of the chimney which had been cut away to install a beam that supported the false ceiling.  There is no need to be neat as the bricks will be covered.

bricks-replaced

In the middle of the ceiling there was a big square hole which seems to have been made by an electrician for some reason. It lent itself perfectly to a square of woodwool board screwed to some 2 by 2 attached to the joists.

woodwool

I later tried screwing some woodwool board behind some lath on a smaller hole but the screws didn’t hold in the woodwool so that’s a poor approach.

It doesn’t matter much as it’s only a very small hole and the plaster itself will provide enough strength to hold itself up.  For a bigger hole there would be a need to attach some actual wood behind the woodwool to provide something to screw in to.

woodwool-above-lath

The edge of the false ceiling had been cross nailed to the lath supports using very big nails.    Removing the ceiling caused a lot of damage to the lath and plaster.  On this occasion after removing the loose plaster the supports were mostly exposed so I could just replace the broken laths with new ones the same way they were installed originally.

The lath is original to the house (it mostly came off the big I beam) and I soaked it in a bath for a few hours to make it expand before fitting it.   That way it hopefully shouldn’t expand again when it is wet by the new plaster which might otherwise cause the wall to bow.

lath-replaced

I have of course been botching too.    There are some awkward holes which would need to be extended significantly to get back to the joists.

I’ve tried exposing a couple of inches of the ends of broken lath and then attaching new lath to the old lath by cross nailing using lots of stainless brad nails.   The result seems secure.   I considered also using wood glue but the stainless brads should not deteriorate and might allow a little movement over the seasons.   It’s the plaster that is most sensitive to movement so it is better to have a flexible system that allows the application of plaster and then doesn’t interfere too much with how the plaster wants to move around.

laths-connected-to-laths

I’m doing quite well with the ceiling and have been doing the first plaster coat as I go along.   It’s been years and I’m starting to remember how not to apply plaster.  First rule I forgot for lime plaster or anything lime is to put as little water in the mix as possible.   Of course I started on a ceiling and I made a mess.