Lifespan of lathe & plaster ceilings...?

[paulbandler]

In midst of major renovation of modest 1920's cottage including rewiring and installing central heating for the first time in this house. Ceilings are lath and plaster although a couple have been replaced (or covered over) with fibre board some time ago. There are some cracks in the ceiling and some areas where the plaster has pulled away from the lathes.

The builder suggests that they could be made good and last another ~10 years but that the lifespan of such ceilings is about 100 years and that the installation of central heating will tend to accelerate their deterioration. He suggests that over-tacking with 9mm board and skimming would be sensible although to be fair he's not pushing it strongly.

So my question is for the forum is - how long do such ceilings normally last - I really don't want to be doing them again in 10-15 years time...

 

[biffvernon]

There's no reason why a lath and plaster ceiling should fail after any particular time. Find a builder who doesn't want to use boards but will do a repair that lasts a century or more. Or do it yourself.

 

[NT]

Also CH does not kill them afaik. Cracked plaster is fillable, deteriorated plaster is skimmable, and detached plaster is regluable.

I wont say a word about how long a lathe & plaster ceiling would last.

NT

 

[Nigel Watts]

Lath and plaster ceilings can last a good deal longer than 100 years. My house is 160 years old and still has the original ceilings in the principal rooms and many contributors to this site will have much older original ceilings than this.

Lime plaster is much more resilient than its apparently soft and crumbly appearance would suggest. For example it can withstand movement much better than modern gypsum based plasters.

The main problem will old ceilings is that the plaster can come adrift from the lath in places. This can be rectified without either replacing the ceiling or covering it, by the use of large washers screwed into the joists in the affected areas. The screw and washer are recessed into the plaster then the recess is filled in.

If some areas of plaster have to be replaced, most modern builders will recommend taking the lot down and replacing with modern materials. This again is not necessary. Old lath and plaster can (and arguably should) be mended with traditional materials. Laths can be mended or replaced with new laths, and haired lime plaster should be used for the repair. These material are all available, but not from a bog standards builders merchant. Most builders and plasterers will not know how to use these materials. Modern materials are not better; they are used in preference to the old ones because they are more convenient for builders/plasterers to use.

 

[Lime]

The lifespan of a plaster and lath ceiling is primarily dependent on the nails used to install it. Most nails used in the past were ordinary uncoated steel/iron and subject to rust.
If a ceiling has been dry and respected for what it is (vulnerable to careless damage) there is no reason to suppose such a ceiling could not last for centuries.
Plaster board by comparison, given exactly the same poor conditions that many plaster and lath ceilings are exposed to, would fail miserably leaving nothing but nails.

It is a modern misconception that a soft material is not as longlasting as a hard one.
Lime mortar and plaster are often condemned because they can be raked out easily.
However that softness is their true long-term strength allowing for movement and consolidation theoughout the lifetime of their use.

 

[middi]

Lath and plaster ceilings tend not to last more than a century or so if we are lucky , only because we interfere with them .

Left alone and with little maintenance they will last hundreds of years.

" Upgrading" to install services for living comforts is the biggest destroyer, lack of knowledge and expertise about reinstating a lath ceiling or wall to its original condition becomes too tedious for tradesman and the short "modern" cut is applied----PLASTERBOARD------

Eventually the ceiling will look patchy with diffent plaster stratas and the next owner will rush to B&Q over the weekend, rip down the "bad" ceiling, and buy 5 or 6 eight x four, a skim of multi-finish and ends up with a new ceiling.

Job done ------- History in the skip------

The CO will never know, most of the owners don't even know he exists.

It is all down to the individual owner as to what will be conserved or destroyed on a period building feature if there is no listing.

 

[thiambal]

Our last house an 1890s cottage has its original ceilings downstairs. One of them looked in particularly bad condition with some serious sagging bits. Every tradesman we had through took a sharp intake of breath when he saw them but we resisted pressure to replace.

Then we replaced floorboards in the room above and throught, that's it the ceiling will come down with all the banging. Anyway, 3 years later it is still there! Meanwhile a wall we had plastered in gypsum (before I knew the wisdom contained on this site) is cracking terribly!

 

[Penners]

There's no reason why a lath and plaster ceiling should fail after any particular time. Find a builder who doesn't want to use boards but will do a repair that lasts a century or more. Or do it yourself.

Of course, you will need more than one lathe for an entire ceiling. This one was constructed by a gentleman from Poland.

 

[paulbandler]

Thanks for the tips everyone - I have spoken to the builder about making good what is there, and bar the couple of grunts of consternation, think he happy to do his best. Couple of consequential questions then are:

- I've read elsewhere of 'plaster washers' that can be used to re-fix blown plaster ceilings to the lathes, but can't find a source in this country (several US web sites feature them). Can anyone advise whether I can get them here (quickly)?

- I will need to get some cornice formed to match the slightly interesting 'modernism' style in the cottage - does anyone know where I can get this done in the South East (Oxford/Berks/Hants/London) area?

 

[Gervase]

You can use galvanised 'repair washers' from B&Q and almost any other hardware shop. They're about the size of a twopenny piece with a hole in the middle.

 

[NT]

- I will need to get some cornice formed to match the slightly interesting 'modernism' style in the cottage - does anyone know where I can get this done in the South East (Oxford/Berks/Hants/London) area?

in your own house would usually be a good place to do that. If you post a pic of the cornice you might get more feedback as to how it was done and how to do it again.

NT

 

[thiambal]

http://www.butcherplasterworks.com/

Have never used them, cannot vouch for their work - but they fit the bill.

I will need to get some cornice formed to match the slightly interesting 'modernism' style in the cottage - does anyone know where I can get this done in the South East (Oxford/Berks/Hants/London) area?

 

[mark_j_k]

The ceilings in our house (1905 semi) are lath and plaster. They are craked and uneven in quite a few places, I've looked in the loft and found that alot of the ceiling joists had started to come away from the main beams. A few coach screws later and all is sound again.

 

[MDE]

We have a lath and plaster ceiling in our house that is probably 200 years old as it pre-dates a partition wall that was constructed underneath it in the early 1800's.

 

[Penners]

The lath and plaster ceiling on the first floor of our house pre-dates the house by about 120 years. I think the ceiling was left in place when the rest of the earlier house was demolished and rebuilt.

 

[middi]

Now the mistery is solved, thanks Penners.

" having a roof over our head" must have been before we thought of walls, and the time that the slogan originated. :wink:

 

[Nemesis]

This could be of interest to someone:


http://www.butcherplasterworks.com/about/opportunities/index.shtml