Replacing an old lathe and plaster ceiling.
Here are a few tips for removing an old lathe and plaster ceiling- from removal to painting.
As you can see in the photo chipboard and wood batten have been used to cover up an old lathe and plaster ceiling. Although not apparent in this photo parts of the ceiling were sagging and once the board was removed sections of the hidden plaster fell to the ground- potentially quite dangerous. After removing this the next stage was to remove the old lime plaster. This is a messy job and I made sure I had a good mask, goggles, ventilation and plenty of rubble bags to fill as I knocked the plaster from the lathes. As the plaster is removed it creates an incredible amount of dust so if you are not removing the carpets then be sure to completely seal them as normal dust sheets will not suffice and be warned if the doors are not sealed this very fine dust will creep throughout the rest of the house. After bagging the plaster I then removed the lathes- wooden struts that were used to push the plaster into. You'll need a good claw hammer to pull them from the joists and the areas near the walls take a little more time as the lathes are secured between the joists and wall and it can be fiddly getting them out. After removing them I completely cleared the room, letting the dust settle overnight.
Now I had removed the old ceiling, and before replacing it with a new one, I thought it best to check the joists and brickwork to make sure everything looked ok. As you can see in the photo there were sections of bricks that had been removed and I could actually see next doors joists- which is unusual. Possibly they had been replaced and as a result bricks had been removed but according to todays fire regulations this is a no no. If there was a fire then smoke/fire could travel through to the adjacent property though these openings- I therefore filled the gaps with a fire retardant expandible foam to comply with building regulations and prevent this from happening in the event of a fire.
The other problem I noticed is visible in the next photo- a small amount of water ingress has slowly been rotting a roof support. This enabled me to advise that this needed to be investigated further prior to the new ceiling being put in place. A small section of cement was missing from the dividing roof wall and this was slowly letting in rain water- by following the water trial to the roof we could then make sure the repair had been successful with the next downpour of rain- of which there were many in this wonderful summer we've just had- grumble, grumble- just checking youre hanging in there with this enormous post- don't worry- you're almost there...and on.... Its best practice to anticipate anything that could prove to be a issue whilst it is accessable and before its covered up.
When these two problems had been rectified the ceiling was ready to be insulated. In this case we opted for an acoustic grade insuation which provides both thermal and sound insulation as there was a room above. A tip for insulating is to cut across the roll of insulation and measure as you cut lengths. Although more time consuming it will be more accurate, you'll waste less of the expensive material and the area will have better insulation. Often the space between joists is slightly different so instead of trying to keep the insulation in place you cut just over the measurement and it holds itself in place.
Before boarding I PVA'd the area where the walls met the ceiling. As you remove the old ceiling it is difficult to remove the lathes and plaster without losing some of the wall plaster- so prior to boarding I sealed any dusty lime plaster that had been exposed. The ceiling was then double boarded with a silver back plaster board to add extra sound and thermal insulation. Again, as there was a room above it was necessary to double board the ceiling to comply to building regulations.
After the ceiling was skimmed a window was left open to allow sufficient air flow for the plaster to dry out naturally. This usually takes 3/4 days depending on temperature. It was then ready for a thinned down coat of white emulsion to seal the plaster and two further coats to finish the job.
Oh and one final comment...phew...its worth planning your lighting and electrics sockets for any rooms above before you board the ceiling- its much easier than pulling up the floor boards above when done. Thankyou and goodnight. I'll try and make these posts a little shorter in future- i just cant help myself..it is literally fascinating stuff.