External wall insulation is it any good?

[Mark 5]

"A point being made was as it was a council owned property, I think it highly unlikely the council would jeopardise their own property by employing slap shod methods when it comes to exterior wall insulation"

Really? It depends if the pen pusher has friends in the right places, the list of failed council "upgrades" is endless. You can lump housing associations in with this lot too.

Oh yes, I have come across this, both council and HA but corruption/backhanders rear their ugly heads everywhere.

But now a day it is a tighter ship but it still goes on.

London has a burnt out tower block, yet to be demolished to emphasize your point.

As I wrote. it does depend on the Council and their confidence in their contractors.

@dextadriver reading these posts but be getting the jeebies, however I don't think they should be concerned or caused it.

 

[gaz1]

roof already overhangs the walls about about a foot in most places... we were going to get rid of that when we re-roof

right now we have essentially 4 rooves

imagine 2 rooves next to each other with a valley between... then another 2 the same at 90' to those

our thinking is if we need to re-roof anyway might as well swap to 2 rooves and get rid of the valleys

would mean we could open up the loft too.. we don;t need to open it up... but might as well

still waiting on the price tho... it could be crazy

(we're getting rid of most of the chimneys too)

EDIT: google earth roof photo

i would reduce chimneys but wouldnt get rid of them all, chimneys do come in handy if you have to return back to old methods

if a power cut does happen you have no heating yet a stove or even a rayburn can keep going in that method

warmth food being cooked and hot water can be gotten from that type of stove

as goes for your roof your on about a flat roof over the valleys becareful they have there own issues

though a flat roof means you can then go up into a loft room if you beam it right you would get way more room up there though i would wall it at the left side as goes for the right valley you will have fun with that one

some victorian houses have both a flat roof style to a pitch roof but they was leaded on top of the roofs

 

[gaz1]

You are mis-understanding the purpose of exterior wall insulation.

No matter how good insulation is, no property, modern or old is heat leak proof.

Exterior wall insulation does help retain heat in the property but it has other benefits to as I explained in reply to @dextadriver.

Poorly installed insulation causes nightmares.

you dont get what im saying

if the wall is concrete built like many council flats and high rise buildings where it a solid wall then external insulation is a good point however it comes with a but it needs maintanence as it does crack lets say 10 years and needs replacing on the cement render side of it

but not where there is an air brick and a gap between the internal and external walls ( cavity ) as that area breaths

if anyone is advised to install with a cavity its a con from the very start of it

( cavity filled ) causes damp cavity fillled with an air gap cavity is different that means front wall removed and cavity wall installed and then rebuilt again

internal insulation is next that has its own issues but is the better side of it however fastening stuff to it is fun

mine is a solid wall with soil filled wall and needs to breath that also means i need to use a frame and insulate that type instead but it causes a draft between the soiled filed wall and the insulation frame

whilst i dont like the con of pink grip filled composite board stuck on it unable to breath

 

[Gareth J]

External insulation in my opinion is often a better general idea as it retains thermal mass, assuming internal radiant heat sources and adequate ventilation.

Also raises the temperature of walls, pushing their dewpoint outward, beyond the masonry. Basically eliminating condensation risk.

if we fitted ewi we'd fit one of those whole house heat recovery ventilation thingies.... we're tempted anyway but there's a lot of things going on all at once we'd like to get out of the way first

I think we’d just use standard extractor fans in the bathrooms, don't like the idea of trying to push all that steam/moisture through vents/ducting etc.

Could use a hybrid approach. In ours, we have a, probably undersized, mvhr unit that ticks over extracting stale air and replacing with fresh, preheated, low moisture content air. In the ensuite, above the shower, there's a high flow extractor that uses the same vent but bypasses the mvhr (achieved with a couple of non return valve flappers) when running. You could do it more simply with a second vent. Don't think the house is well sealed enough for it to cause issues.

 

[knighty]

i would reduce chimneys but wouldnt get rid of them all, chimneys do come in handy if you have to return back to old methods

if a power cut does happen you have no heating yet a stove or even a rayburn can keep going in that method

warmth food being cooked and hot water can be gotten from that type of stove

as goes for your roof your on about a flat roof over the valleys becareful they have there own issues

though a flat roof means you can then go up into a loft room if you beam it right you would get way more room up there though i would wall it at the left side as goes for the right valley you will have fun with that one

some victorian houses have both a flat roof style to a pitch roof but they was leaded on top of the roofs

we're keeping 1 chimney, rest can go, solar+batteries+heat pumps we'll be ok in winter with a power cut

we'll put a wood stove in the one we keep, more to relax in front of than actual need for heat

not flat over the valleys, I mean take the full roof off, new trusses/gable ends etc.

 

[knighty]

Also raises the temperature of walls, pushing their dewpoint outward, beyond the masonry. Basically eliminating condensation risk.

Could use a hybrid approach. In ours, we have a, probably undersized, mvhr unit that ticks over extracting stale air and replacing with fresh, preheated, low moisture content air. In the ensuite, above the shower, there's a high flow extractor that uses the same vent but bypasses the mvhr (achieved with a couple of non return valve flappers) when running. You could do it more simply with a second vent. Don't think the house is well sealed enough for it to cause issues.

how many vents do you have for the mvhr? proper build to spec houses with them do every room... (I think?)

upstairs will be easy, downstairs would be murder

 

[Gareth J]

how many vents do you have for the mvhr? proper build to spec houses with them do every room... (I think?)

upstairs will be easy, downstairs would be murder

Have one supply in every bedroom, one extract in every "dirty" room (bathrooms and kitchen). Managed to get a kitchen extract via the bathroom cupboard above.

One more bodged supply in the kitchen, via same bathroom cupboard and a stud wall, which I think probably adds more draughts from outside than anything else. And one more supply planned for the living room, which should be reasonably simple via a built in wardrobe. If that works, I may ditch the kitchen supply.

Yeah, downstairs is a pig unless you're doing significant renovations.

Upstairs is notably fresher and measurably better air quality in the morning when comparing on Vs off.