Should We Remove Water Damaged Lath & Plaster Ceiling Or Just Plasterboard Over It When It Has Dried Out?

[karsten2@btinternet.]

Should We Remove Water Damaged Lath & Plaster Ceiling Or Just Plasterboard Over It When It Has Dried Out?

Hi All
Had a major water escape in loft over Christmas which has seriously damaged two rooms. Insurance are going to pay. I'm all for the existing lath & plaster ceiling to be taken down and replaced with plastered over plasterboard - seems the cleaner and more logical thing to do. My brother (who I co-own the property with) is of the view that once the ceiling has dried out it is better to just plasterboard over it. His points are: 1. the old ceiling will provide a layer of heat and noise insulation 2. less general upheaval. I'm uneasy with this. Is there a mould issue here? Makes more sense to me to pull down what's damaged and replace with plasterboard. What's the view?
Thanks

 

[RandomGrinch]

Part of my decision making process, would include looking at your existing joists.
If they are the undersized and bowing 3"x2"s that I have, I would not want to add another weighty layer of plasterboard and plaster below them.

 

[Dereekoo]

If insurance are paying do a proper job and replace

 

[conny]

A couple of things.
Yes, you may think it's dried out but there could still be damp in the core of the old plaster and laths which, as you say, may lead to mould issues at a later date.
If you are getting a builder/mate in to do it, he will submit a quote for a full rip down and replace. If he/you/your brother decide to cut corners and leave the old laths up you could be in trouble for fraud.
As @RandomGrinch says, check your joist sizes. If they are undersized, or bowed in any way, then you could be storing up trouble for the future with potential movement due to expansion/contraction during the different seasons.

My advice would be a full rip down and complete replacement. You may even be able to claim a re-decorating allowance depending on your policy terms.

 

[karsten2@btinternet.]

Thanks for the above comments, especially the caveat about residual damp in the core of the old plaster and laths. Under the policy the builders are appointed by the Insurers and it seems they are recommending a complete "strip out". A full replace is my preference as it seems to be a "white" solution as opposed to a "grey one" (to use IT parlance), especially given that it has suffered water damage (rather than just being old and having some cracks) . However, is there going to be a noise issue (eg people walking around, talking etc) from the room upstairs if the ceiling now becomes just plastered over plasterboard? Will one lose the heat insulation properties that the old lath & plaster ceiling provided? Can this be remedied? Also, if they plasterboard over the existing ceiling and therefore lower it a bit, is that going to make the frieze look odd (ie gap betweeen picture rail and ceiling)?

 

[oldbutnotdead]

Your old lath and plaster ceiling is fairly heavy so will be doing a decent bit of airborne noise reduction. If they do drop the old ceiling, stuffing the void with soft acoustic batts will help a bit (try and get the builders to hide that on their quote, insurers will see it as betterment).
If it's a single home you don't generally worry about thermal insulation between habitable rooms- the heat isn't being wasted.
Up to you to decide whether lowering the ceiling will ruin the relationship between picture rail and ceiling.
If the old ceiling is still fairly sound (when you prod it do bits fall off or not) you could consider a false ceiling- much easier to get flat and level and an added noise barrier

 

[Deleted member 174758]

...but there could still be damp in the core of the old plaster and laths which, as you say, may lead to mould issues at a later date.

Or better yet an ideal nursery for dry rot?

My advice would be a full rip down and complete replacement. You may even be able to claim a re-decorating allowance depending on your policy terms.

Having ripped out more than my share of lath and plaster walls and ceilings over the years I will point out that it is an extremly dirty, thankless task, and that no matter how well you wrap or sheet over stuff in the building, the soot and plaster dust will find its' way into absolutely everything

If the old ceiling is still fairly sound (when you prod it do bits fall off or not) you could consider a false ceiling- much easier to get flat and level and an added noise barrier

Even if they are not sound,v they can be netted (chicken wire held in place using screws into the joist and mudguard washers) and a framework suspended below that to carry boards or ceiling tiles

 

[karsten2@btinternet.]

Thanks. There has been some good feedback to this thread. Yes the dust and mess issue is a consideration but they are going be taking a lot of plaster off the walls anyway. The key thing for me in this is the fact that the ceiling has been water damaged. And given Midlands weather it will take ages for it to completely dry out for sure. Plus given the heating costs these days we are not giving it much help on that front either. I certainly don't like the idea of the gap between the plasterboard and the existing ceiling being a breeding ground for dry rot in the future!
Also what would happen if at later date the existing and supposedly dried out water damaged ceiling started to crumble/collapse etc after it had been covered over and hidden with the "just get them to plasterboard over it and then forget about it" solution? I imagine the Insurers' builders guarantee won't apply if we go that route.

 

[Deleted member 174758]

I certainly don't like the idea of the gap between the plasterboard and the existing ceiling being a breeding ground for dry rot in the future!

The main thing to realise about dry rot is that on order to survive it needs moisture. On commercial refurbs whole building dehumidifiers are often used to dry out buildings quickly, partly to deal with this. Dry rot spores are in the environment all around us - getting and keeping buildings dry ensures that the can't get the chance to become established and spread

 

[conny]

Having ripped out more than my share of lath and plaster walls and ceilings over the years I will point out that it is an extremly dirty, thankless task, and that no matter how well you wrap or sheet over stuff in the building, the soot and plaster dust will find its' way into absolutely everything

My first rip down, (in a domestic property), was my childs bedroom in my first house. Having done a few commercial rip outs I knew what to expect regarding dust issues. So I taped up the bedroom door from the outside, put a ladder up to the sash window to get in and out, taped up the door from the inside, back out the window, (which I left wide open), then into the house, making sure I closed the back door behind me and putting the 'snake' draught excluder into place. Goes up into the loft and started to kick the ceiling down.
A couple of things went wrong. My ex-wife opened the back door to hang some washing out, (despite me telling her a lot of dust is going to come out the window, ), she also left the back door open and then to compound it, I forgot to close the loft hatch whilst kicking the ceiling down!

Oh happy days!