conflicting advice re. insulating solid walls

Dear group,
My home improvement programme is in danger of being held up due to conflicting advice I have received regarding how to attach insulated plaster boards to 9 inch solid brick walls built with lime mortar.
Brent borough council insist on battening and hence a generous air gap over brickwork with no waterproofing treatment applied directly to the wall :-
http://www.brent.gov.uk/bccs.nsf/24878f4b00d4f0f68025663c006c7944/bda0a799ca60698c80256c1d0047621d/$FILE/BCCS%20Dry%20lining%20Solid%20Blockwork%20info%20sheet%20No.7.doc
A video made 10 years ago by a local university shows waterproof sand/cement render being applied then the insulating boards attached with adhesive dabs, the boards then being skimmed.
The outside of the wall is rendered and I don't appear to have problems with penetrating damp
yours,
"confused" of Bristol
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The Council are simply requiring you to follow current building control standards. These change over time and what was considered appropriate ten years ago is often different from that now required. These rules apply across the country not just to Brent. Under certain circumstances they can allow a particular job to be done in a different way if it is considered appropriate.
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"brugnospamsia" snipped-for-privacy@blueyonder.co.uk says...

http://www.brent.gov.uk/bccs.nsf/24878f4b00d4f0f68025663c006c7944/bda0a799ca60698c80256c1d0047621d/$FILE/BCCS%20Dry%20lining%20Solid%20Blockwork%20info%20sheet%20No.7.doc
I'd go with the council - applying modern materials to old buildings can lead to problems when it disrupts the movement or breathing of the structure, which a waterproof render is likely to do.
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plaster
over
http://www.brent.gov.uk/bccs.nsf/24878f4b00d4f0f68025663c006c7944/bda0a799ca 60698c80256c1d0047621d/$FILE/BCCS%20Dry%20lining%20Solid%20Blockwork%20info% 20sheet%20No.7.doc
sand/cement
dabs,
with
Knowledge on old houses has come on a lot in the last ten years. Look at www.periodproperty.co.uk for a variety of articles on the subject.
We had to remove some of this waterproof render applied some twenty years ago as the wall had gone green. Removing it of course took some of the lime mortar with it so this had to be redone as well.
Once dried out, we used an average two inch gap (varies a bit as property is random stone), and again no waterproofing applied. Make sure the air gap is well ventilated. Upstairs is easy into the eaves but downstairs can be a real pig. You need to put in airbricks and monitor whether damp is collecting behind the insulation which of course is somewhat difficult to do as you have to leave temporary access panels and plaster these up later. If damp does collect you need to add more airbricks or a fan until things stabilise.
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Gawd, it gets worse and worse !
One thing I'm trying to avoid is having to pay for too much skimming so I was hoping to avoid mechanical fixings. I wonder if I could attach the boards to the battens with adhesive ?
The main problem I see is the difficulty in sealing on the warm, moist side where the boards meet the floor.
Where adhesive is recommended it is laid in a grid to form sealed cells.
Perhaps a hybrid system would work with boards attached to the battens with adhesive and with battens along the floor well sealed to the wall with mastic ?
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my idea :-
http://uk.geocities.com/gentlegreengiant/walldetail.JPG
========================

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SNIP
Why do you have this maina for fixing the boards with adhesive - whats wrong with plasterboard nails through the boards into the battens?
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wrong
I'm trying to avoid paying a plasterer to skim the boards afterwards - hoping to use taper-edge boards and special filler.
If I could have used "dabs" it would have been a 10 minute job :-) yours,
"Skinflint" of Bristol
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I see you haven't discovered Gyproc Easyfill then ? :-) My wife can produce a plaster finish so smooth even the paint falls off :-) (well not quite but you get the point)

side
Yep - Do you have a solid or vented underfloor. If the later it is easy. For the former, the best solution is to actually build a false floor and vent this as well. Kingspan on the underside of the floor (i.e. similar to what you are doing on the wall) increases insulation considerably.
Also if the floor is solid, does it allow damp through from under (stone or tiles on soil, lime concrete, etc) or is it impervious to water (real concrete) ?
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Both are suspended floors. Looks like I'll be insulating the downstairs floor and improving the ventilation under it. Since the upstairs floor will be a warm / moist environment, I will either have to continue the air channel / insulation through the floor between the joists or have seperate vents through the wall upstairs.(may have to be the latter - especially as the joists run front to back and I'm quite likely to be replacing one of the upstairs floors and using wallplates and hangers )
No doubt there will be horrendous temperature differential cracking if I don't insulate the wall under the upstairs floor ....)
It's a pity the kitchen is not being done for a bit as I have broken all the rules there. It is the most exposed part of the house with every kind of wall construction (but plastered) - all battenened with 1 inch of expanded polystyrene slab crammed in, then leaky ply wallboards so I will see if all this palarver is really neccessary :-)

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wrote>> Dear group,>> My home improvement programme is in danger of being held up due to

insulated plaster

gap over

wall :-

sand/cement
adhesive dabs,

problems with

If your wall had been unrendered life would be much easier. You could simply use a vapour barrier, PB and rockwool.
Unfortunately unDPCed solid walls should not be rendered on both sides, nor vapour barriered on both sides, since damp will slowly accumulate in the wall, and have nowhere to go. Injection DPCs do not solve the problem.
Since youre already cement rendered on one side, you dont want to be attaching any form of vapour barrier to he inside.
Yet if you use PB and glass wool, a vapour barrier you would need.
The possible solutions?
A. Remove external render, with real care to avoid damage, then proceed with vapour barrier internally. Dont cement render these old buildings, it can damage them.
B. Apply expanded clay in lime plaster to the interior. This gives insulation with no vapour barrier, retaining wall breathability, and without the damage cement sometimes causes.
C. Do nothing.
Your idea of venting to the loft might work, I dont know. It would make damp worse in winter, but then dry it in summer. But if you do that you will lose out on insulation value, and I didnt see where in your sketch the rockwool is going.
In principle I imagine you could install PB with vapour barrier and pipe the trapped air to a micropower drying unit, never heard it tried.

hear hear
NT
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from snipped-for-privacy@meeow.co.uk (N. Thornton) contains these words:

Not a solution I have previously heard of. How effective is that plaster mix as insulation?
I am in a similar position to the op other than I have 2' thick rubble filled stone walls and no external render.
--
Roger

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(N. Thornton) contains these words:

I use it for floors as it needs to be a lot thicker than Kingspan/Celotex or even Rockwool. LECA (Optiroc) in a lime/sand mix to a foot or so depth definitely does lower heat loss through the floor though. A friend did put a thin layer of it as an outside render but this was on a 'best attempt' basis rather than trying to meet part L.

Same here.
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I had a google but couldn't find any reference to its use as wall insulation. One of my round tuits near the top of the pile is to dig up and re lay my solid ground floor but I think I will avoid the expanded clay route as I would probably have to dig out to below my shallow foundations. I can't afford to raise the floor level at all as headroom is aleady minimal.

I note you have gone the batten out route but I have small rooms and particularly in the kitchen, smallest bedroom and bathroom no space for more than the thinest of insulation. One of my earlier jobs (still not plastered out because of the insulation dilemma) was to increase the size of the bedroom at the expense of the bathroom so space is really tight in there now.
--
Roger

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contains these words:

plaster
Kingspan/Celotex or

put
www.periodproperty.co.uk appear to have cleared their back files but google has some cached. Start with
http://www.google.co.uk/search?q che:Wc6-9uwqKbcJ:www.periodproperty.co.uk /cgi-bin/discuss/forum.pl%3Fread%3D3966+LECA+render+site:www.periodproperty. co.uk&hl=en%20target=nw
and work from there. But you will have to search the google cache, not the web site itself.

Same here. Remember there is still a lot of sand and lime in the mix so use very little clay in the mix near the wall (or none even - just leave it as is) but a lot in the centre of the room. A couple of feet of this stuff is definitely noticeable.

Fully understand. Ours is a very long 16'8" wide farmhouse internally with 2' walls each side so we decided to sacrifice the 8" for insulation, 4" on each side - 35mm typical ventilated space, 50mm insulation and 12mm plasterboard+skim. The alternative was heating bills of over 5k per annum so it wasn't too hard to sacrifice the space. In your case I would superinsulate the loft and the floor, plus work on draughts and suchlike. Are you allowed to double glaze ? (but not with PVC please :-)
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{ Apply expanded clay in lime plaster }

Thanks. I will try that tomorrow. I wasn't previously aware google had a cache.

2 feet would definitely get below what little foundations I have. ISTR that most heat through the floor leaves close to the walls so insulation is more important there. Someone in the past replaced most of my (presumably stone flagged) floor with poor quality concrete with a dubious dpm. I am inclined to just go the modern route for the replacement.

Double glazing is one of the few jobs I have got a builder in for so far. Double glazed with hardwood frames to replace the rotting single glazed softwood. Some of the window openings showed evidence of long departed stone mullions but I decided not to attempt to reinstate those, the windows are very small by modern standards already. I didn't enquire about the type of glass. :-)
As to loft, only in one small section do I have a loft, the remainder of the upstairs is open to the pitch of the roof. Luckily this place is not listed. Nothing worth listing in the first place I suspect, it is only a humble cottage attached to a larger field barn. My heating bills aren't too bad but I could do with something on the walls that makes a significant difference without eating space. I can't afford more than 2" on most of the external walls and in some places more than an inch would be an embarrassment.
--
Roger

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headroom
use
as
is
Foundations are probably six inches so don't do anything near them. But all the ground is fairly cold. Anything helps.

Always a difficult choice. A concrete floor pushes the damp into the walls as these have no DPC. But if that is what you have now and the walls can cope then I'd pull the soil back two or three inches and lay plastic, Kingpan then wood as a new floor.

How good is the roof underside ? Kingspan pressed between the roof timbers and plastered over is effective and looks fairly original except the timbers appear not so deep.

Thick lined curtains the size of the wall. Expensive but can look superb. Also consider improving the outside. Adding a porch, lean-to or even a cloche can keep cold away from the outsides of the wall. Also make sure the exterior pointing is up to scratch and no wind is entering the rubble cavity in the middle. Some stone appears second only to metal in conducting heat but at least if it has to escape through the whole 2 feet you're making it more difficult for it to do so.
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The spars ar lathe and plastered over. Only the purlins (debarked tree trunks) and the ridge pole are visible. I could tear down the l&p but it would be a long and messy job and in the centre tricky. My scaffording tower will reach but that sways alarmingly when working on it at anything that requires an effort.

Tapestries? My pension doesn't really run to things like that and I have some complications to take into account. Namely one side of the doorways into the kitchen and 2nd bedrooms are flush with the outside wall and the stairs exit straight from the living room (headroom a modest 5 feet) and again flush with the outside wall at the intermediate landing.
The South side of the house (where both doors are) is reasonably sheltered from the worst of the weather but the North side and West (gable end) aren't and with a restricted vehicle entry past the NW corner much of that area can't be extended although I do have a pipe dream about a stair turret further along to get the stairs out of the living room but the planners may have something to say about that as they are more than a little snooty about any development within their extended green belt. (It wasn't green belt when I moved here).
The outer skin of the house is reasonably intact unlike the barn where the wind blows right through in places.
--
Roger

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Plenty of classes on such things :-)

Don't want to alarm you then but do keep an eye out for movement in this area. Large loads transferred into the outer random stone wall like this can cause the wall to move, albeit very slowly. Un

Then point this out in the application and say you intended to do it all along, discretely mentioning that you think your human rights have been violated by this. Usually works. AFAIK no council has yet won a full blown human rights planning judgement.

If the roof does the same then get it fixed or in these gales you soon won't have a roof.
Good luck.
Mike
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I am all thumbs when it comes to anything like that. :-)

I am not so alarmed now as I used to be. The end section of my house was once a separate one up/one down with its own staircase and before than just a single storey byre. Whoever broke through to form the downstairs doorway caused a partial collapse in the wall above leaving a huge bulge tenuously held together by a cement corset in one of the 2 leaves of the wall. The bulge was such that the through stones had pulled out by an alarming amount. One of the scariest things I have every done was to rebuild that area in sections. Never did get all the throughs completely back in place but the worst one is only a couple of inches out.
The upstairs breakthrough was much later and done by my predecessor. The plans he left me called for a horizontal lintel but he was inordinately proud of the rough roman arch he had constructed instead. Removing the arch is the only other job I have called a builder in on in recent years. The crack between the side of the stairs has now closed up slightly but the doorway into the second bedroom has cracks in the plaster above and sooner or later I will have to investigate that. The alterations flowing from the projected stair turret would need that particular lintel being raised almost to the purlin above but on the plus side would provide a buttress for that wall. Meanwhile I need to complete various other lesser jobs before I can even contemplate taking on what could easily take me a whole year to build given the speed I work.

The thought had occurred to me. No modern house would get away with even 6 feet over the stairs.

The roof has roofing felt under it but Yorkshire stone slates take some lifting, particularly the rougher ones that are well over an inch thick.
--
Roger

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