Ceiling - sound and heat insulation

[BlueC]

Hi all, another question...

We have a ground floor 1890's flat, and as we love punishing ourselves we're thinking of ripping down the ceilings throughout which are lath and plaster construction and have been overboarded very badly - not skimmed, papered directly over, nail heads showing through, lost definition of the cornicing, etc - arrgh! While we're doing this it is clearly a good opportunity to introduce some insulation for both sound and heat as well as inspect the timbers above for signs of rot. Our flat is cold even in the summer so I'm dreading the winter and if the upstairs flat ever take their carpets up then the noise transmitted through the floorboards will be pretty bad.

So, whats the thoughts on doing this? Do we just push up some insulation between the joists? If so, what kind of insulation is advisable? I guess I am mainly concerned about any risk associated with reducing the air flow in the spaces between the joists... is this a valid concern? Anything else to be wary of?

We'd like to do the same with the basement ceiling too and is there anything particular about doing that which we should be aware of? Perhaps more concerned there about the airflow as the joists are nearer to ground level and also don't want to reduce the ventilation of the basement as it is pretty damp down there!

Thanks for any help or advice.

Chris

 

[vicky whitworth]

Hi Chris and welcome. Are you a troll?

 

[BlueC]

Hi Chris and welcome. Are you a troll?

Umm, no. What have I posted that could be considered "trolling"? That's kind of insulting. I made two posts asking for the advice of people on here that probably have far greater experience and knowledge of these things than I do.

If I'm not welcome, or the people here are as unwelcoming as you, then I'll find another forum.

 

[JoceAndChris]

I'm sure that Vicky was simply trying to convey her horror at your proposal to pull down the historically interesting, irreplaceable, and authentic ceilings. What is clearly of no interest to you many on here would try very hard to conserve - it's a forum for people who treasure period properties, not pulling them to bits and turning them into modern sealed boxes. I appreciate most mistakes are made in ignorance, and appreciation of hidden things such as ceiling structure is something that grows as you live in the property longer - certainly I had no idea when we moved in that we'd spend £1000 saving our reed and lime plaster ceiling in the dining room.

A few pics would help to clarify the state of your ceilings. It sounds like they need any modern plaster board picking off if at all possible, plastering in lime and then painting with distemper.

Insulation against cold could be created with draught proofing any windows or doors, and hanging thick curtains.

As for noise - we always found that a discreet word, about how noise carries, and how living in such close proximity we always tried to be very considerate about our own noise, helped ease potentially difficult situations.

 

[BlueC]

I'm sure that Vicky was simply trying to convey her horror at your proposal to pull down the historically interesting, irreplaceable, and authentic ceilings. What is clearly of no interest to you many on here would try very hard to conserve - it's a forum for people who treasure period properties, not pulling them to bits and turning them into modern sealed boxes.

Hi JoceAndChris.

I think I am being misunderstood here - we are trying VERY hard to conserve our property, but I am not a purist and I'll happily use modern materials where I think appropriate. We have already had all our original sash windows restored, draft proofed, and reconditioned rather than replacing. We are even replacing, at some cost, a horrible 1960's retrofit window with an authentic replica of the original sash windows, and have also commissioned new lead lights for the top transoms in the front of the house to be faithful replicas of the originals which have sadly been replaced/smashed (only 2 remain). In fact, I have a keen eye for detail and rejected the first lead lights we had made because they'd used the wrong lead! We are also conserving all the interior woodwork and cornicing etc. Unfortunately the house has previously been let for over 50 years and many of the original features have been well, modernised, and done badly (cheaply) in many cases.

The ceiling has been ruined by this cheap modernisation and it is my desire to return it to its former glory that prompted this thread. It looks dreadful with the overboarding because it has ruined the definition of the cornicing and has also been done badly such that the plasterboard nail heads are visible through the nasty paper they have covered it with.

A few pics would help to clarify the state of your ceilings. It sounds like they need any modern plaster board picking off if at all possible, plastering in lime and then painting with distemper.

Thanks, I'm not sure whether the board would come off without pulling down the original ceiling, it is certainly something I will look into but I don't think its a realistic option.

My thoughts are that the original lath and plaster has probably had it, so to return to the original aesthetic I would consider removing it (and the overboarding) so that we can board directly on to the beams then have a skim put over that and restore the cornice edging where required. While this might not be to the purists taste, my question still stands about what we might consider to use for insulation in this case that would not have a detrimental affect on the timbers above.

Insulation against cold could be created with draught proofing any windows or doors, and hanging thick curtains.

Yup, we're of the same opinion - as mentioned above we have had all the windows extensively restored and draft proofed. We'll also be using thick curtains and draft proofing the doors etc. That said, its a cold flat and any further insulation we can provide above the ceiling would be most welcome.

As for noise - we always found that a discreet word, about how noise carries, and how living in such close proximity we always tried to be very considerate about our own noise, helped ease potentially difficult situations.

Indeed.

 

[JoceAndChris]

Thanks very much for your detailed post and all the clarification. It sounds like you really do want to do the best for your property and look after all the lovely history that you're now the guardians of.

I agree with you that having the cornice cut off is unacceptable. My own - albeit limited - experience of getting ceilings repaired by tradesmen is that the majority of them would sooner put in an easy, modern plasterboard one, skimmed with cement. That's a lot quicker than restoring what's there.

I'm not sure if you intend to do the ceiling work yourself but you might find with careful soaking, chipping, prising and scraping you can get the unsympathetic plasterboard off and have a damaged lath and plaster ceiling that can then be repaired properly. That was certainly the case when I began the process of stripping our badly sagging, 200 yr old ceiling - admittedly it wasnt covered with board but with layers of woodchip, paint and older papers. I didn't think it would stand up to days and days of soaking and scraping but it has. Screws were put in at various points to anchor the old plaster to the framework, and a huge amount of new lime was patched in. The work after stripping was done by a company specialising in the repair of old buildings - several plasterers had given the ceiling the death sentence prior to them saying, pretty much, that most old fabric can be saved - it's a question of how much you want to spend on it.

Have a look at the before, during and after pics on Page 4 and Page 8 of this thread.

http://www.periodproperty.co.uk/forum/viewtopic.php?f=1&t=11521&hilit=Onto+ceiling+rewire+before+repair&start=45

It may be that as well as repairing the old lath and plaster some sort of insulating can be done, though I can't see how really - sorry.

 

[vicky whitworth]

Sorry Chris, didn't mean to upset you. I would love to have lathe and paster ceilings here - all ripped down, plaster boarded over, and then fake beams stuck on (I promise the beams have gone now). I hate that flat, cold effect a plaster board ceiling has. It has no sole, and personally I'd rather be cold with a beautiful ceiling, than toasty. I hope you can find a way to save the ceiling.

 

[LadyArowana]

Sorry Chris, didn't mean to upset you. I would love to have lathe and paster ceilings here - all ripped down, plaster boarded over, and then fake beams stuck on (I promise the beams have gone now). I hate that flat, cold effect a plaster board ceiling has. It has no sole, and personally I'd rather be cold with a beautiful ceiling, than toasty. I hope you can find a way to save the ceiling.

Someone wake Mr Penners, there is a fishy situation needing his attention.

 

[Flyfisher]

No need to carp on Milady, he's clearly missed the bait - unless he's just needs more time to mullet over.

 

[Andrew Bodenham]

Hi, Chris,

Sounds like you're taking a pragmatic approach to balancing conservation and improvement, which I applaud. I've replaced several failed lath and plaster ceilings here with plasterboard; others have been repaired. Each case gets judged on its merits.

If you go down the remove-replace route then you can certainly make improvements in insulation and soundproofing. For insulation I'd be tempted to use rigid polyurethane slab (Celotex, Kingspan) as this is easy to fit (wedge fit between joists) and gives more insualtion per mm of thickness than many other materials. With the ceiling down you'll be able to assess the condition of the joists and the void ventilation situation.

Soundproofing can be achieved by adding extra mass to the ceiling, e.g. two layers of plasterboard instead of one, or using a more sophisticated system to provide isolation of the ceiling from the joists. This might involve elastomer battens, or even rebuilding the entire ceiling as a separate structure independent of the floor joists.

You will need to consider the fire performance of any new ceiling, as it needs to meet the regulations to provide protection to flat above in the event of a fire in yours - and vice versa.

Information about all these issues can be found online if you are good at research. Alternatively you could take advice from and architect ot architectural technologist who will advise you on the technical and legislatory matters and produce a specification for the works.

Taking down the ceiling also gives an ideal opportunity to consider your lighting scheme and update any wiring etc.

 

[Lime]

Unless there has been considerable water penetration the only thing likely to be wrong with the laths are the nails.
It's a simple job to renail and a good plasterer can make the ceiling look like it did originally when first put up.
If you have access from above and want to stop noise there is not much better than vermiculite.
I've used it for insulation but the sound deadening and noise reduction was much more noticeable than I expected.
It does everything you'd want: good insulation, good noise reduction and fire proof.
http://www.dupreminerals.com/en/vermiculite/introduction

 

[MatthewC]

No need to carp on Milady, he's clearly missed the bait - unless he's just needs more time to mullet over.

Now he's trying to think of an even better reply to that! :lol:

 

[Johnboy]

Amen to the Vermiculite suggestion. If it came in a tin it would do exactly what it said... and more!

 

[MdB]

Amen to the Vermiculite suggestion. If it came in a tin it would do exactly what it said... and more!

Just don't get it wet...

 

[Lime]

Amen to the Vermiculite suggestion. If it came in a tin it would do exactly what it said... and more!

Just don't get it wet...

Perhaps you could explain that because I don't know what you mean.
It doesn't wet easily and it floats with the trapped air.

 

[MdB]

Amen to the Vermiculite suggestion. If it came in a tin it would do exactly what it said... and more!

Just don't get it wet...

Perhaps you could explain that because I don't know what you mean.
It doesn't wet easily and it floats with the trapped air.

My understanding is that if you have a chimney full of it and the chimney is damp, the vermiculite slowly compresses and ends up as a mushy mess which doesn't insulate very well. I could be totally wrong on this, it is just what I have heard.

 

[Lime]

If you have a faulty flue insulated with vermiculite it can absorb water.
Perhaps if the wet mass is high enough and the flue large enough in cross-section it may settle down further than when installed and it could compress.
It won't dissolve.
However the problem is the leaking water and not the insulation.
What other type of insulation would you suggest would be ok for pouring down a chimney/flue?

Not what we are talking about here though.

 

[MdB]

However the problem is the leaking water and not the insulation.
What other type of insulation would you suggest would be ok for pouring down a chimney/flue?

The inside of our chimney is never going to stay dry. It is made from poor quality sandstone which just loves to absorb moisture.

The building regs recommended alternative is Leca mixed 20:1 with cement. I'm sure lime would do equally as well. We had a discussion here before on it and I believe the price came out roughly the same as vermiculite. I'm not convinced Leca used loosely bound like this has as good thermal qualities as vermiculite though. It will allow too much air movement.

What I definitely don't recommend as a chimney filler is sand / broken asbestos tiles and other rubbish which is what we have currently in one of our chimneys. It is slowly shifting downwards pushing the wall apart in the process. Not good.

 

[Lime]

Vermiculite and its other trade names makes an excellent insulating cement that can be poured too.
The big advantage with vermiculite cement is that it is very light in weight.
I use it around items (like pipes and cables) going through walls that will need to be replaced/repaired at some time in the future.
for instance I used vermiculite cement to seal around the electricity supply cable entering the house.
vermiculite cement is solid enough to shape like ordinary cement but may be picked out easily when hard with a small chisel without damage to any other part of the house fabric or the pipe/cable.