If your property has traditional lath and plaster ceilings that are in need of repairs, a common tradesman’s fix is to overboard (cover) them with plasterboard, rather than deal with the original failing plasterwork. Over boarding is a cheap and relatively fast way of repairing an existing ceiling. In some cases it is perfectly acceptable, but there are several things to consider before you decide to proceed.
If you own a listed building you are required to obtain written consent from your local planning authority before making any kind of alterations. It is likely that if lath and plaster exists already, then it will need to be replaced like-for-like.
If listed status is not a consideration and overboard is seen as a solution, care should be exercised to avoid damaging existing pipework and/or electrical cabling within the ceiling voids. Accidents can often occur when fixing blind through the plaster.
Should the existing lath & plaster ceiling be bowed or uneven, plasterboard will follow the contours of the existing structure, in some cases accentuating any irregularity. Any overboard procedure will reduce the ceiling height by at least the thickness of the plasterboard (12.5mm), more if the boards are suspended, so rooms of low ceiling height should be carefully considered.
It is possible to remove the old plaster before you plasterboard a ceiling, but this creates a lot of dust and mess. You should be aware that in the early twentieth century, horsehair used as a binder was soaked in Ammonia, which can cause lung and respiratory problems for your occupants and workers if not correctly addressed.
Benefits of lime plaster
Plasterite has been restoring lime plaster in buildings for 45 years. Lath and plaster is a traditional building method used to finish interior walls and ceilings. It is more time-consuming to apply than plasterboard but certainly has its benefits.
- Lath and plaster tends to retain less moisture than plasterboard, with breathability a key benefit to preventing damp and mould. It also better tolerates a small degree of movement and irregularity in a building’s construction.
- Compared to plasterboard, lime plaster is a better insulator, both for sound and for heat. You will be amazed that many historic buildings are warmer and quieter than modern ones, despite perceived advances in construction technology.
- Finally, lath and plaster is generally better than drywall at stemming the spread of fire within a building should this unfortunate instance occur.
Taking into consideration all the above, it makes each case a specific decision as to whether you affix plasterboard directly to an existing plaster ceiling, remove the plaster and affix to the joists and beams beneath, or replace your ceiling with new lath and lime plaster in the traditional way.
As heritage plaster experts, we are advocates of conserving and restoring buildings using original methods. Therefore, should you require more information on lath and plaster ceilings and wish to receive a quote for restoration, please call or email us.