Ian Anderson - 12 Ways to Fix Lath and Plaster Ceilings: Complete Do-it-Yourself Guide for Homeowners

A s a general contractor working predominantly in the UK for more than 30 years, Ive worked on more than my fair share of lath and plaster ceilings. From restoring them in period properties, to ripping them out in turn of the century terraced houses and starting afresh with drywall. Ive seen many variants, from wonderfully crafted works of art, to awful ones quickly thrown up by cheap industrialists, and even some with reeds instead of laths.

Although Ive removed countless lath and plaster ceilings myself, Im always a little sad when an original ceiling hits the floor in a cloud of dust. I just cant shake the feeling that the house has lost a little of its character and is all the poorer for it. As you can probably tell, I adore lath and plaster for its charming authenticity and skilled construction. Although I might say something slightly different after Ive just removed one and Im totally covered in very old black dust, incorporating the odd mouse skeleton, thrown in for good measure

However, I hope you love your lath and plaster, even if it does give you sleepless nights! Lets go and take a quick look at your ceilings, then we can run through some of the options you have to repair and keep them. Alternatively (and sadly); if needs must, Ill show you how to remove them safely and install new ceilings, either with like for like laths and traditional lime-based plasters, or more commonly, with modern drywall boards and gypsum based plasters. But first, some housekeeping notes

What is Lath and Plaster?

Up to the 1950s before drywall became common, thin wooden laths were nailed to ceiling joists (leaving small gaps in between) and plastered. In the UK, split or riven hardwood* lath was the norm, but sawn timber was common in the USA. The plaster consisted of two coats of a lime/sand haired mortar, followed by a two thin finish coats, trowelled to a smooth, flat surface. The thickness of finished ceilings varied from 19mm (3/4) up to around 28.5mm (1, 1/8 th ). You might find thinner or even thicker sections, especially in older houses built with hand cut joists or those built using recycled materials (spars from old ships etc.). *oak or chestnut usually.

What is Drywall?

You might be wondering why Im calling it drywall. Well, Ill use the word drywall in this book as a handy catch all term because these boards have many different names in other countries. In the UK, we say plasterboard but in New Zealand its gib and in the USA the brand name s heetrock is common. Other generic names include baseboard, gyproc, gyprock, gypsum board and wallboard. Moreover, on a building site its often just boards.

Im living in Norway these days and here we call it gips, derived from gypsum I guess, since all drywall boards consist of a gypsum-based plaster slurry encased in-between two sheets of very thick paper. This creates strong, cheap, and easily worked building boards.

Is it Lath or Lathe?

Lath. End of lesson. In case youre interested a lathe is a machine for turning round bits of metal (or wood) and the plural of lath is laths (although we could probably argue a little about that last one)

Is This Book Relevant for Lath and Plaster Walls?

Oh yes indeedy. Youd use the same principles and methods to repair or remove it from walls also. Only its a little easier to remove because youre not standing directly underneath all the muck!

Plastering on lathed walls is a bit tricky though, as the mortar can easily just drop off the back of the lath as you push it though. Whereas on a ceiling the mortar squeezes through the lath and forms beautiful mushroom shaped keys.

Inspecting and Evaluating Ceilings

P eriod charm probably led you to buy an older house in the first place; after all, why would you go through the trials and tribulations of owning a gently decaying pile of bricks if not? Along with the soft honey coloured lime mortar and moss-covered roof tiles, your lath and plasterwork undoubtedly add to the period feel of your home. And if your home is a highly listed property, your local authority might insist you repair and keep them.

However, for the average home, the big question facing most owners is how to find a practical solution that doesnt spoil the very charm and feel that tempted you to buy the house in the first place.

In a period house, improvements are often a compromise between originality and practicality, oh and cost

To find a suitable solution though, we have to be pragmatic; accepting that times change and that our needs and expectations change with them. For example, modern recessed light fittings are difficult to fit into a lath and plaster ceiling, at least not without a lot of work, (often youd need to cut out squares of the lath and plaster and patch them up with small squares of drywall, which is fiddly and time consuming).

Cost is also a major factor for many people when deciding what to do with a damaged ceiling. During initial renovations of a newly acquired house for example, replacing a ceiling with drywall is not that big a hit on the budget. However, repairing and restoring a damaged original ceiling in a finished home is time consuming, more technically difficult to do well and of course more expensive. This prompts many people to remove ceilings (arguably prematurely) as a safeguard against bigger bills in the future.

The case for keeping original ceilings isnt helped by the fact that any competent DIY enthusiast or local tradesman is capable of removing an old ceiling and installing drywall to a good standard relatively cheaply. Whereas unless youre very confident with the wet stuff, you might need to hire in expensive and often difficult to find skilled plasterers to replace a ceiling in a more traditional manner using age appropriate materials.