Advice: Wall insulation, heating, &etc

[Cocoa]

Hello all,

I have put in a few hard days' work over the Christmas break, and my upstairs has gone from in need of an update, to absolutely frightful! Anyway, I have been left with a few questions and I was hoping you would be able to offer some thoughts and advice (be warned this is a bit of an essay!)

Here's my top floor, before and after my labour. Sometime (I think possibly in the 50's) the walls were covered with this delightful mdf/chipboard type panneling. Not nice, and less nice after water damage, but I can understand why they would have done it, as the plaster behind needs some work.



As I have done my lime course at Mike Wye's, I am keen to have a go at the replastering myself, I ws thinking of using ecocork to provide some extra insulation. Has anyone tried this?
http://www.mikewye.co.uk/mikeprices.htm#ecoCORK

The house was built in 1820. The external walls are two layers of stone with rubble infill. Bafflingly, below all the windows the walls are only single skin. The nasty Georgian repro windows have been replaced with wooden double-glazed sashes and the stone mullions replaced as well, but the draught below the windows is still palpable. (and I know that the sealant used by the windows guys is not age-appropriate, breathable &etc - I just hope that as it is limited to just around the windows it's going to be ok!)



So, questions are:
(1) I phoned Mike Wye's and asked about using pavadentro thermal wall insulation board just underneath the window. However, the response was that if I only insulate one section of the wall I would create a thermal bridge, one part of the wall being better insulated than the rest. But I don't understand why this should create an issue, as by being single rather than double skin, this section of the wall is less insulated than the rest - would;t I just be evening things out?
http://www.mikewye.co.uk/naturalproducts.htm#Pavadentro
(2) Another option is to build a small stud wall and put thermafleece behind it. Would I need to use anything between the external wall and the insulation, to stop it getting damp and mouldy?
(3) Some deep architraving had been added around the windows at some points in the building's life, which came down with the rest of the panneling and the installation of new windows. If I am insulating under the windows and creating a deeper sill, then I don't see any need to ut it back. How would I plaster around the corners? Would I need to use metal beading, or could I just plaster straight onto the stone and create a more rounded corner? http://www.diy.com/nav/build/building-materials/plastering-plasterboard-coving/plasterers_metal_work/Expamet-Plasterboard-Edging-Bead-13mm-x-3m-9273240?skuId=9282940
(4) Not sure if you can see it, but above the window there are some wooden beams. I believe that they would have been plastered originally, but that plaster is really blows and is about to come down. (breathing lightly on it should about do it!) Any need to replaster over, or could I just leave the beam exposed? Are there any building regs that would prohibit me from doing that?

 

[Cocoa]

Further to the spot under the windows: I thought I could site my radiators there. There is no central heating in the house, so I am starting with a blank canvas. The idea would be to insulate, then install radiatiors and a radiator cover, which would be flush with the rest of the wall.

 

[Cocoa]

And now for my final question!

As I mentoned, the ceiling had also been boarded over. Underneath, there are toungue and groove floor boards nailed to the underside of the joists. Above that, there is just the attic.




I am planning to remove the paper with a wallpaper stripper and then paint over. My concern is the amount of debris that might drift down from the attic. My plan upstairs is to insulate using warmcell (loose insulation, due to non-standard widths betweeen attic joists!) and thermefleece to top it up. I then planned to board over the top of the insulation with lofts boards
http://www.diy.com/nav/build/timber/sheet-materials/chipboard/length_1220mm/Loft-Panels-Pack-of-3-L-1220-x-W-325-x-T-18mm-9276266?skuId=9285966

When I was removing the ceiling panels I did get quite a bit of dust, dirt and grit, but maybe not as much as you'd think if they have been up the for 40 odd years. I would hope that loft boards would prevent any dirt filtering down from the roof itself, but would I get insulation particles filtering down through the gaps in the boards?

 

[Cocoa]

With slightly larger photos!

 

[plasticpigeon]

The photos aren't very clear. Are the windows recessed from the rest of the wall as seen from the inside? If that is the case once the walls are plastered/finished the reveals will be even deeper. Perhaps you could put in a window seat, and wooden paneling in the reveals. There are people on this forum who know loads and are really enthusiastic about Georgian properties so I'm sure good ideas will come. Looks like a big project. It would be great to see more photos.

 

[Cocoa]

Yes, the windows the area underneath are recessed from the rest of the wall by approximately 20cm. Hopefully this photo shows that a little more clearly:



Most of the walls are already plastered, although it does require some holes to be filled in and, I suppose, to be reskimmed (although I am sure you will all have a better idea than I do of what will be required. Under the window there is currently no plaster at all.. This is where I thought I could use pavedentro / plaster with ecocork / build a small stud wall and add insulation.
In that case, I felt that I would be adding to the thickness of the recess, rather than the rest of the walls.

Perhaps you could put in a window seat, and wooden paneling in the reveals.

I had thought about this, and I may do this with one window (perhaps in the living room), I have the same situation with the bedrooms and the bathrooms, and I am not sure I can install window seats throughout! 15cm-20cm probably a bit narrow for a seat...

I can feel the cold underneath the windows!

 

[Roger H]

Hi. Looks an interesting project. Sorting out how to insulate without creating further problems is a nightmare in my view.

Insulating under the windows will not create a cold bridge – it will just mean that comparatively the remaining uninsulated walls will then be the ‘worse area’ – prone to condensation or cold to the touch for example. If the wall under the window is dry I would perhaps frame it out as PP suggests and install a window seat with plenty of rockwool or something behind. A potential issue with all of this - and I am wrestling with the same problem – is that once moist air gets behind your surface finish (T&G, pboard, whatever), it is likely to condense on the cold internal wall surface. This could make the insulation damp and therefore not very effective.

I’m not aware of a sensible solution to this issue – using a vapour barrier as conventionally prescribed is extremely difficult as sealing its edges and avoiding penetrations of it e.g. from fixings, is near impossible.

 

[Cocoa]

once moist air gets behind your surface finish (T&G, pboard, whatever), it is likely to condense on the cold internal wall surface. This could make the insulation damp and therefore not very effective.

That is exactly what I was concerned about! Only, I didn't realise that this would make the insulation less effective. I did think that it might cause the insulation itself to get mildewy and maloderous - could that be a problem as well, or are most insulation materials treated to prevent this?

 

[Roger H]

Hi Cocoa.

That thinning of the wall under Georgian windows seems to be a common detail - which I assume may have been to allow access to viewers peering out of the windows without stubbing their toes? And also to throw additional light onto the floor that a full depth cill would otherwise intercept?

I would suggest boxing it out in treated timber, set a fraction off the wall, and inserting kingspan (rigid foam insulation) or similar between the studs. Ok, not remotely 'period' but rigid insulation won’t suffer if any damp is ever present, (as rockwool might do). I would also seal the perimeter of the studs, and the joints between stud and infill, with expanding foam filler (cut infill panels so they are 5mm adrift all round and wedge in place so as to be able to get a good fill of filler around the insulation and achieve a total fit). Also, ensure no moist air can access the void from the room below viua the floorboards. This should preclude moist air from the interior getting into the void. Then box in with tongue and groove, plasterboard or panelling as you prefer...

 

[Cocoa]

Time for an update! The builders have been here for so long I almost feel like chargeing them rent. The place looks quite different though! I took your advice and built a frame out under the windows, installed kingspan, and plasterboarded over. I've gone for the easy option on any new stud walls and opted for gysum plaster board, everything else I have been having a go with lime...and it feels like I am getting the hang of it!

The best bit for me was moving upstairs to the one bedroom - what a change from last summer. No rain through the windows, no whining breeze from around the windows / through the large gap* behind the wooden lintel (now insulated and plastered over) or from the loft (now insulated under the regulation 270mm insulation) It felt snug, cosy, and draught-free...

* large enough to qualify as a small bedroom in any newbuild, I said to myself, at one particularly dark moment!

 

[Cocoa]

Of course, now that the windows bit is 'sorted' (pending a final skim finish and a LOT of painting) I have another question! As I mentioned earlier up this thread, once I had taken down the delightful chipboard paneling from the ceiling, I found that the entire thing was covered in floorboard, nailed to the underside of the joists. Not being keen to change the whole thing for pasterboard, I left in situ...but was a bit worried about the dirt of the ages filtering through from the loft space above.

So, after clearing about 30 sackfuls of rubble from down there, I got the Dyson out and hoovered up all the crud from between the boards from above. Then laid builders paper down, insulated, and boarded over. I'm now busy vacuuming up from UNDER the boards in the room below...but there is still an awful lot of very coarse, dirty grit when the ceiling is disturbed (i.e. when I try to hammer in the nails which are sticking out all over the shop). It should be old stuff, rather than any new dirt gathering, but there is still an awful lot of it.

What to do? I'd like someting that would bind any dirt, but could also be painted over, as I am planning to limewash the ceiling. I thought of linseed oil putty, but the various posts on here suggest it is quite difficult to apply successfully. Is just bog-standard wood filler a better option? earthborn do a casein filler and there are a few others on the market too... could this be a more eco option?
http://earthbornpaints.co.uk/product/casein-filler/
http://www.oldhousestore.co.uk/casein-filler-volvox-485-p.asp

Or am I barking up the wrong tree entirely?

 

[Greg.Hobson]

May I please I add an interest on this last posting?

EVERY ceiling in our house is the same as the photo in the last post - floorboards under joists above. In some rooms the ceiling is painted (with gloss), some with a modern (Yacht) varnish and a few just bare, but with the remains of a previous plaster in the knot holes. We are also in West Yorks but I have seen very few (less than 1 in 10) other houses of the same era with this ceiling construction and have long been interested in what is the "correct" finish to apply.

We also suffer from bits falling through the gaps from the room above. most notably round the edges where the walls become streaked with accumulations of dust. I try telling SWMBO that it is a "feature" (Yes, I used to work in IT).

 

[davidbrac]

never done this before, but l would think about a diluted PVA to stabilise the dust as you are going to lime wash the boards, this would hopefully stabilise the dust/grit. l would also look at hiring a ceiling/drywall sander as that will get a lot of the dust down whilst preparing for a limewash coating.

However this would not fill the gaps just stabilise what is already there.

 

[Cocoa]

We also suffer from bits falling through the gaps from the room above. most notably round the edges where the walls become streaked with accumulations of dust.

:shock: Oh dear. Maybe that explains why the previous owners had it all boarded over! I had hoped that there was a way of escaping the grit!

My house is about 200 years old, and I think that this ceiling dates from some gentrification about 100 years ago, rather than being part of the original fabric of the building. From what I understand, the top floor of the building would have been one big room open to the rafter, as a weaving workroom. There is a lot of thick string (or thin rope) hanging from the rafters, which my builder informs me was part of the loom. Maybe that's why you haven't seen this too often, as it is not actually 'original'?

l would think about a diluted PVA to stabilise the dust as you are going to lime wash the boards, this would hopefully stabilise the dust/grit. l would also look at hiring a ceiling/drywall sander as that will get a lot of the dust down whilst preparing for a limewash coating

I spoke to Wormersley (Greg, if you're in West Yorks you may find these guys really useful, they're based in Heckondwicke) who doubted thatn there was any natural product that would do the job... I had been hopeful to avoid any product containing PVA! Anyway, I have succumbed and I am going to have a go with ordinary decorators caulk. As it's white, I figure it won't stand out when I get to the limewashing. I will definitely take your advice with the sander however... I invested in one, and am a bit aghast at how expensive those litle velvet backed sanding sheets are, given how quickly I whip through them (and there seems to be acres and acres of ceiling & beams to sand!) :roll:

I'll let you know how I get on....

 

[worms]

You don't quite say it, but it sounds like you have confirmed that your limewash will adhere to the caulk? I wouldn't have expected that it would but have never tried - I would want to do a test patch just to confirm.

Depending on the size if the gaps, could you try a papier-mâché made from newspaper and limewash? I have never found linseed putty difficult to work with and it can be diluted down with linseed oil to make a very sloppy mix that you can paint into fine cracks, but I have only ever used it where I was then painting with a linseed oil paint, not sure if limewash will work over putty (although my home-made limewash does seem to stick to my home-made linseed and sand mastic, so I suppose it might).

 

[Cocoa]

Thank you for the advice, Worms... I have just logged on and seen it!

No, I believe that the limewash won't stick to the caulk... the thought was that, if I were using white caulk and then whitewashing the ceiling, it simply wouldn't be that noticable!

The gaps between the boards are about 1/2 cm wide and the same deep - I have tried the caulk and used up a tube quite quickly, but I struggled to find a tool which was the right size to smooth the stuff down between the cracks. I like the idea of a paper mache, but don't I need to use something with some kind of a bond (i.e. flour and water?) The builders have also left a good deal of sawdust... I wonder if that might be usable rather than paper, but using limewash or a flour-water glue? Is this something that you have tried?

I might reinvestigate linseed putty if it IS easy to work with. I imagine I won't want it too sloppy as I am pointing a ceiling, and don't want to end up covered in the stuff myself, which is highly probably as I have yet to find a way of dong DIY tifily...

 

[worms]

Might a rope-type caulk be the answer? Or even sisal twine pushed in with a chisel?