For some unknown reason, our Methuselah electrician's Dad plastered in all the lintels around the windows, we suspect he also took the lintels and mullions in the front room to put in a picture window. J'accuse fashion. When we had new windows fitted in the bathroom we knew the plaster that still clung to the windows wasn't going to survive, the window fitters tried, the brought in beading and left happy, a few months later the beading remained but the plaster had fallen off. We knew it would, we just hoped it wouldn't. Hope is folly in an old house. Hope is folly with an old horse. They become horse hair plaster that falls off.
This is were Andrew coughs, shuffles his feet and looks at the bookcase. Falls off, in this case, is code for Andrew 'testing' the plaster with his 'fingers'. For 'fingers' see hammer. Suffice to say that those dull thuds in the middle of the night became loud crashes in the afternoon followed by muffled yells of, 'I'm alright'. You'd run upstairs to find Andrew stood in the bath, holding a hammer, and denying that he had anything to do with the plaster dust that was everywhere.
So, Andrew cleared the lintels, it literally peeled off, he sneezed once and a four foot section fell on the windowsill. The stone is an improvement. We noticed some mould under the plaster, locked in moisture led to black mould. For those of you who have black mould in your house it can and does cause respiratory problems, so get rid of it. The best way to get rid of it? White vinegar, 50:50 with water on walls, or 100% white vinegar on stone and the mould will die, just wipe off and then seal with 50:50 PVA glue and water.
We chased out all the joints, finding slivers of wood holding the lintels together which we had to gingerly cut back in case that was their job, but more than likely they were ties for the horse hair plaster. We filled from one window four rubble bags of plaster, dust and horse hair.
Then we mixed some mortar and started to point around the windows. For those of you who have never made mortar, it's three sand to one cement and one lime, and mix it to the consistency of play dough. We need to silicone around the new windows were there is building foam to finish the windows.
We have scraped all the paint off the stone windowsills and pointed the gaps between the stone and the window, the beading has gone and the results seem to bring in more light than before.