Non-motoring > Insulation on the outside	Miscellaneous
Thread Author: Soupytwist	Replies: 33

New Mon 11 Apr 11 13:41   Insulation on the outside - Soupytwist

I'm looking to improve the insulation on one wall of the house which doesn't have a cavity. I saw on a recent edition of that programme with Nick Knowles that isn't the Lottery show that it's possible to add an insulating outer layer of render to walls. Does anyone have any experience of having had this done? Does it work? Thanks Last edited by: Soupytwist on Mon 11 Apr 11 at 13:44 Reply to this message | Report message

New Mon 11 Apr 11 13:48   Insulation on the outside - Clk Sec

I wouldn't think that a layer of render would make a significant difference. Reply to this message | Report message

New Mon 11 Apr 11 13:55   Insulation on the outside - Fenlander

I think the system is to fix some high performance exterior insulation panels to the outside and then render over that. All the local authority houses round here were done a few years back with a similar system but the panels already have a pebble dash render type finish. BTW is it heat insulation or damp you're wanting to resolve? Last edited by: Fenlander on Mon 11 Apr 11 at 13:56 Reply to this message | Report message

New Mon 11 Apr 11 13:59   Insulation on the outside - Dog

I was having a chinwag with a near neighb last week, they live in a similar 1930's dwelling built using single 9" blocks, They reckon that they had the render removed, and an insulating 2" finish added, They say it has drastically reduced their heating bills, And the cost? £6k. Reply to this message | Report message

New Mon 11 Apr 11 17:34   Insulation on the outside - Soupytwist

Dog, was that for the whole house or just one wall? Thanks Reply to this message | Report message

New Mon 11 Apr 11 14:09   Insulation on the outside - lancara

This may be of interest: www.greenfootsteps.com/best-insulation-for-homes.html But beware of this: www.siginsulations.co.uk/condensation.htm As ever, it's sensible to get somebody with experience to advise when altering a building. Reply to this message | Report message

New Mon 11 Apr 11 14:31   Insulation on the outside - devonite

you could go "all posh" and have it Stone-clad" ala Duckworths on Corrie!! Reply to this message | Report message

New Mon 11 Apr 11 14:35   Insulation on the outside - Alanovich

Surely the answer is to insulate from the inside: tinyurl.com/y9dotex Reply to this message | Report message

New Mon 11 Apr 11 14:56   Insulation on the outside - Dog

>>Surely the answer is to insulate from the inside:<< Trouble is, all these energy saving systems cost 000's, and it'll take years before you're quids in, Better orf moving house - like moi, unless you intend staying put for 10 years or so. Reply to this message | Report message

New Mon 11 Apr 11 15:02   Insulation on the outside - Alanovich

1000's? Huh? tinyurl.com/3v3bqv9 Reply to this message | Report message

New Mon 11 Apr 11 15:12   Insulation on the outside - Dog

>>1000's? Huh?<< Well that's like anything Alanović, if you DIY it - a new boiler would cost me £500 ( W.Bosch) but another £1500 to fit + update my system. Reply to this message | Report message

New Mon 11 Apr 11 15:24   Insulation on the outside - CGNorwich

Dry lining an entire house isn't something that most DIYers would be comfortable with and as you say Dog it would cost 1000s for a even a small property and would be hugely disruptive to achieve. The amount of re-decoration would be massive and you would probably save around £150 p a Reply to this message | Report message

New Mon 11 Apr 11 15:34   Insulation on the outside - Dog

That's right CG/N, I was interested in what my neighbs had done to the external walls though, and if we were intending to stay here until "the end", I would consider having the work carried out. Reply to this message | Report message

New Mon 11 Apr 11 15:40   Insulation on the outside - Alanovich

>> Dry lining an entire house The OP says he wants to do it on one wall, not the entire house. Reply to this message | Report message

New Mon 11 Apr 11 15:50   Insulation on the outside - CGNorwich

Still a tricky job especially if there are any windows involved and not sure how you would deal with the gap between floor and ceiling. Potential savings would also be a lot less. Reply to this message | Report message

New Mon 11 Apr 11 15:53   Insulation on the outside - Soupytwist

Funny thing is, two of the four rooms which have that north facing wall in need re-plastering anyway so we could end up dry-lining inside and insulating from the outside. Neither are particularly large so it would be great not to lose any interior space. Reply to this message | Report message

New Mon 11 Apr 11 15:56   Insulation on the outside - Fenlander

As mentioned below I've dry lined the north and east walls upstairs & down as part of a larger house makeover. I found in ours the old plaster was so thick once it was all hacked off we only lost about 20mm per wall once the dry-lining was added. The work to deal with the extra wall thickness around the windows is a bit of a pain but we had all the timber framing out anyway for the new windows. Last edited by: Fenlander on Mon 11 Apr 11 at 15:57 Reply to this message | Report message

New Mon 11 Apr 11 16:18   Insulation on the outside - Soupytwist

Sounds like you've done what we're considering doing. If you don't mind me asking, what was it about your situation that led you down that particular path? Did you work it out yourself or did you get some outside 'expert' input? TBH Fenlander, I imagine you've got the requisite nous yourself. Reply to this message | Report message

New Mon 11 Apr 11 16:43   Insulation on the outside - Fenlander

Our place is very exposed out in open country so every bit of insulation helps. We'd been aware just how cold to the touch the north and east walls were. Also some of the plaster on those walls was in poor condition so we'd decided to take the walls back to brick and start again. Seemed as easy to do a batten and plasterboard (with vapour check on rear) job with a final plaster skim as have it fully plastered with all the drying out time. As we were replacing the windows we already had all the old sash timberwork removed so the extra work for us to make good to the slightly thicker wall wasn't too bad. In addition I was replacing the skirtings anyway so another job that wasn't an extra. The results have been worthwhile but it is no good thinking you can take advantage of all the new double glazing/doors keeping everything shut up tight or the mould will return in a couple of cold spots. One behind a bed in an upstairs north east corner and the other inside an upstairs unheated wardrobe with an external north wall. I planned the work myself and did most of the plaster removal then dry-lining. For speed I got the guy who was doing the plaster skim to dry line a couple of walls but he wasn't quite so careful with the straight lines and levels... not that you notice now it's painted and furnished. HTH Last edited by: Fenlander on Mon 11 Apr 11 at 16:45 Reply to this message | Report message

New Mon 11 Apr 11 15:46   Insulation on the outside - Soupytwist

Thanks for the replies everyone. We're looking to eliminate the growth of black mould on walls and ceiling which we're reasonably certain is due to the condensation and cold - in turn that's likely to be down to knackered double glazing on the rather large bay window and the large north facing solid brick wall and rudimentary loft insulation. We're prepared to spend some money and are looking at properly dry lining the entire north facing wall on the inside or maybe going for one of the exterior insulation options. Comfort is our main objective, saving on fuel bills would be a welcome bonus. My problem is that I am not confident of getting an unbiased opinion from someone who's not pushing a certain product or solution because there's something in it for them. How would I find someone to advise without an axe to grind? Last edited by: Soupytwist on Mon 11 Apr 11 at 15:47 Reply to this message | Report message

New Mon 11 Apr 11 15:54   Insulation on the outside - Fenlander

Black mould is very likely to be the result of poor ventilation and too great a moisture input into the house. In such houses powerful kitchen and bathroom extractor fans and/or leaving windows open is a must. We've just about solved this mould issue in our 1920s solid wall house with a combination of internal dry-lining on the north and east walls but most importantly with the aforementioned jet engine sized extractor fans. Note this mould wasn't really such an issue until we had the whole place double glazed and new doors fitted a couple of years ago. Once a place is so well sealed the condensation has to drop out (ie mould location) somewhere and it will always find somewhere in an old place. Reply to this message | Report message

New Mon 11 Apr 11 16:01   Insulation on the outside - Soupytwist

What I haven't mentioned is that it's got worse in the bedroom since the previous general bathroom was made into an en-suite with a mains pressure shower, a window with no trickle vent and what I always thought was a rather asthmatic extractor. The final two were dismissed as concerns by the people who did the work, I was neither knowledgeable nor assertive enough to get them changed. Presumably without the draughty double glazed large bay it would even worse! The kitchen has a pretty powerful extractor fan, and the new general bathroom is in the well insulated new bit of the house and has a decent extractor. The bedroom can be strikingly cold though. Reply to this message | Report message

New Mon 11 Apr 11 16:03   Insulation on the outside - CGNorwich

I agree - ventilation is the key. Old draughty houses never suffered from black mould. The only way to avoid condensation is to heat the house and ensure a reasonable level of ventilation. A human being give off over 2 pints of water a day in their breath and by sweating. Combine that with steam from cooking, showers and baths and you can easily have a daily gallon of water condensing on the coldest wall or window in the house once the air is saturated with moisture. Reply to this message | Report message

New Mon 11 Apr 11 15:56   Insulation on the outside - Alanovich

The Energy Saving Trust is an impartial organisation. They have local advisors on a freephone number. www.energysavingtrust.org.uk/Contact-us Reply to this message | Report message

New Mon 11 Apr 11 16:05   Insulation on the outside - Soupytwist

Thanks I'll give them a go. Reply to this message | Report message

New Mon 11 Apr 11 16:18   Insulation on the outside - Fenlander

Many extractors sold and fitted are completely useless... folks so often go for the easy choice of a generic 4" extractor. Even worse is if even a short duct or hose is added to these then they hardly work. Also the ratings given for them are into free air... if they face the prevailing wind they'll almost go backwards. An en-suite shower need s a really powerful extractor to avoid problems in adjoining rooms. Reply to this message | Report message

New Mon 11 Apr 11 16:25   Insulation on the outside - Alanovich

>> An en-suite shower need s a really powerful extractor to avoid problems in adjoining rooms. >> Which doesn't mean it has to be noisy. We've just had an extractor installed in an en suite for this precise reason (mouldy walls) and it's very powerful and yet almost silent. It can suck pieces of paper up to its vent (it's installed in the ceiling and vents out through the loft). Haven't had a spot of mould develop since it was installed (November). After a nice hot power showering, there is no mist on mirrors nor windows. Highly recommended. Reply to this message | Report message

New Mon 11 Apr 11 16:30   Insulation on the outside - Soupytwist

Sounds good - do you have the make and model number handy please? Reply to this message | Report message

New Mon 11 Apr 11 16:35   Insulation on the outside - John H

>> Sounds good - do you have the make and model number handy please? >> I think you could benefit from a "Mechanical ventilation and heat recovery system". cocoonair.co.uk, ventaxia, xpelair, and others make such systems. www.kiltox.co.uk/products/hrv.htm www.screwfix.com/p/vent-axia-multi-vent-3-room-installation-kit/29928 Last edited by: John H on Mon 11 Apr 11 at 16:37 Reply to this message | Report message

New Mon 11 Apr 11 17:37   Insulation on the outside - Dog

>>I think you could benefit from a "Mechanical ventilation and heat recovery system".<< That's another good way of going about it John H - there was an old disused system installed in this house when we moved in, I had no idea what it was at the time, not having seen one before. The Surveyor who came here and did a full buildings survey (gulp!) for our buyers, recommended them. Reply to this message | Report message

New Mon 11 Apr 11 16:32   Insulation on the outside - Fenlander

Yep spot on A. This is the sort of thing you usually find... www.screwfix.com/p/manrose-axial-20w-bathroom-fan/15722 Add a bit of duct or prevailing wind and you can drop the 85cu.m/hr rating to nearer 30cu.m/hr which isn't enough. This sort of thing is better... www.screwfix.com/p/100mm-mixed-flow-fan/26867 The 250cu.m/hr rating is a max and they have a slower speed if you need... plus they are designed to work against the resistance of a duct so you'll probably maintain 150cu.m/hr even in difficult circumstances. I've fitted three of those, two roof venting and one wall venting. As they are in the loft voids all you hear is the whoosh of air through the vent. Reply to this message | Report message

New Mon 11 Apr 11 16:42   Insulation on the outside - Soupytwist

That looks pretty substantial - especially compared to what we've got at the moment! I might get a spark in to sort that out now rather than wait til we make a decision on the rest. Reply to this message | Report message

New Mon 11 Apr 11 17:02   Insulation on the outside - FotheringtonTomas

I have been looking into this. It certainly works. It will deepen the window apertures. Window-sills may need extending (overlays). Roof drainage may need re-doing. A variety of fixing systems and finishes available. No grant for such work (yet?)! If the external finish of your house allows it, a very good thing, by the look so far. Reply to this message | Report message

New Mon 11 Apr 11 17:53   Insulation on the outside - Iffy

Spending less time in the shower each time will reduce condensation, energy costs and save water. How virtuous is that? Reply to this message | Report message