# Forum Home Renovation Structural Renovation  Insulating existing brick veneer walls

## Compleat Amateu

G'day 
In these wintr'y days, one's thoughts turn to insulation, lots of it. 
My specific problem is that part of the house is brick veneer, but when it was built terracotta vents were inserted into the wall ABOVE the floor line, i.e. there was no significant ventilation direct under the floor, venting was into the cavity only.  I've now solved that problem, Aleta vents under the subfloor. 
The next task is to insulate the walls.  2 questions arise:
1. What';s the best way to get the insulation in there?  I don't like blown insulation, I've seen it bridge the cavity, I'd rather take the plasterboard off, batt the walls, and re-board.  Messy, but not difficult.  But is there any other way?
2. With either method, do I seal up the old terracotta vents in the process?  Why would I not do that, since the subfloor ventilation no longer relies on them? 
Hope this rant makes sense.  SWMBO doesn't know about the mess next Easter yet, Easter being the favourite time for these projects .......

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## pauljygrant

On first thoughts, what type of roof covering do you have?  Would it be possible to lift off the bottom row of tiles or colourbond to access the top of the wall cavity.  Then slide down the insulation.  Would not be easy and would only get as far down as any horizontal timbers in the wall framing...only a suggestion to get discussions started. Paul

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## Compleat Amateu

Ahhhh .. tile roof and raked ceilings, so no.  Project #3 is to take the bloody tiles off to insulate the ceilings, but as 6m off the ground, that's a job for $$$ professionals, therefore somewhat deferred.

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## woodbe

There are a few options. 
You can blow in rockwool or similar fibres, polystyrene beads etc. 
There are some foam products that might suit. Icynene is pretty popular overseas, but not caught on here yet, although there is a local distributor:  http://www.envirohealth.net.au/ 
I don't know what it's like, but it's not cheap. 
woodbe.

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## sundancewfs

One way is to cut out a horizontal strip of plaster board.... 2.1m wide(?) as wide as the narrowest sheet avail... so that you have access to the wall cavity above and below the noggings. You can cut a thinner strip but it makes it harder to feed in the insulation and you then have to cut and fit the repair piece. with a full sheet there should'nt be any cutting nessecary. This can seem like a daunting job, but when you think about it, your only doing the external walls (don't forget to do inside cupboards and wardrobes too) which for the most part have windows in, which in its self reduces the amount of wall space that needs insulating. Think about double glazing too windows are a great way to loose and gain heat. I had a window above our kictken sink that always felt cold, (inside temp 18c, outside temp 6c, inside glass surface 8.4c measured with a Fluke non-contact infared thermometer. I installed a second pane of glass on the inside on the window lite and the internal glass temperature went up to 15.4c) This was just a home made bodge up on an old window that will be replaced at a later date, but it shows how effective simple fixes can be.

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## Bloss

Not sure what your objection is to the rockwool insulation that has been filling cavities here and around the world for more than 60 years, but it seems to be based on a misunderstanding.  
Your initial post dismissed it as 'I've seen it bridge the cavity'.  :Confused:  Well yes - as it is designed to do. The rockwool is waterproof as well as fire resistant and the installation process involves blocking off the cavity along the bottom (between the frame and the brickwork) then blowing/ pumping the rockwool down from the top (with other means for multiple stories). Under windows and other awkward points are accessed by small holes drilled through mortar joints (which are then filled). 
The result in an average brick veneer house will be an insulation barrier of around 140-175mm and from R3.0 to R5. This is the most cost effective form of wall insulation available in Oz (and no I do not have any connection with any manufacturer or supplier, just plenty of knowledge about retrofitting insulation and direct experience).  :2thumbsup:  
Sure there are an increasing number of competing options such as foams, but they are still more expensive and come with their own issues and so far higher costs (and some tricky issues like the need to protect GPOs and the difficulty of later changes to wiring). If you have plenty of time to DIY then the removal of all or part of internal wall cladding and using batts is certainly an option, but will not be simple (especially if you try it via slots) and unless you used waterproof rockwool batts then there is also a risk of moisture transfer over time from batts touching the bricks (you will not be able to tell). 
The options mentioned so far that involve DIY IMO will be much more expensive (even if you do not count your labour - which should be costed in), will take considerable time (blown in usually is done in a day), will be messy & disruptive, give a poorer result, and will result in a lower R-value - as R2 or R2.5 is the largest size batt you would need to use to ensure no contact with the brickwork. 
It is important to consider your electricity cabling when looking at wall insulation (all insulation if any will be over cables or fittings) - all types, including DYI and when getting quotes. Reputable companies will include an inspection by a qualified electrician as part of the quote or insist that you have one done and give them a report. This is to ensure that the cabling will remain within specs when surrounded by the new insulation. Most houses built since the '80s will be OK, but still might need some upgrading, older houses vary a lot but might need upgrading too - and that will be at your cost (which can be significant). Professional installers will leave the concentration of cables into and out of the meter box well clear of insulation in any case (as required by the standards for wall insulation). 
As to the external wall vents above the floor line - close them off as your new underfloor venting will be fine. 
FYI see genral info at -  http://www.heat.net.au/pdf/cavity-wall-factsheet.pdf and although it is a commercial site this has some accurate info -  http://www.ais-group.com.au/homeinsu...ckwooldata.htm  :2thumbsup:  
and see: http://www.yourhome.gov.au/technical/fs47.html  :2thumbsup:  
That site says inter alia: 'The ideal option, (for brick veneer or timber framed walls) if the scope of the renovation permits, is to remove the internal plasterboard linings or external cladding and fit insulation to the stud frame.' As I say above IMO and experience that is true only if the whole internal wall linings are being fully removed so that batts (concertina foil or fibre) can be placed properly & securely )and preferably sisalation installed too if possible). I have done this on every renovation involving wall lining replacement in the last 20 years. Trying to do this with only partial access is simply impractical and costly - and the way the blown in materials have been done for many, many years now there are no residual issues.

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## Compleat Amateu

G'day Oldbloss, and thanks for this thoughtful reply. 
Just a couple of points - 
1. I have had the experience of living in a brick veneer house where some years earlier insulation had been introduced to the wall cavities, with the result that the internal plasterboard had a nice mottled effect, except where the framing contacted it.  Looked very odd.  Not my house, I don't know what material was used, presumably not rockwool;
2. I was contemplating stripping off all the internal linings to insulate, no point in half doing the job.  I certainly accept that not being able to introduce a lining paper as well creates a risk of bridging, unless carefully done.  You may have given me a much less painful alternative, so thanks. 
Do you know who does this process in Sydney?  A couple of random calls from the Yellow Pages didn't produce much joy, it isn't done by all insulation contractors, apparently. 
And any sense of $ psqm?  "In and out in a day" suggests a grand or so plus materials in a place of the size of mine, but it'd be nice to have some idea in advance! 
Thanks again 
Compleat Amateur

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## Bloss

> G'day Oldbloss, and thanks for this thoughtful reply. 
> Just a couple of points - 
> 1. I have had the experience of living in a brick veneer house where some years earlier insulation had been introduced to the wall cavities, with the result that the internal plasterboard had a nice mottled effect, except where the framing contacted it.  Looked very odd.  Not my house, I don't know what material was used, presumably not rockwool;
> 2. I was contemplating stripping off all the internal linings to insulate, no point in half doing the job.  I certainly accept that not being able to introduce a lining paper as well creates a risk of bridging, unless carefully done.  You may have given me a much less painful alternative, so thanks. 
> Do you know who does this process in Sydney?  A couple of random calls from the Yellow Pages didn't produce much joy, it isn't done by all insulation contractors, apparently. 
> And any sense of $ psqm?  "In and out in a day" suggests a grand or so plus materials in a place of the size of mine, but it'd be nice to have some idea in advance! 
> Thanks again 
> Compleat Amateur

  Retrofitted wall insulation should not cause mold and mottling on walls unless there is some other poor design or build factor that allowed moisture retention over long periods. Even in tropical climates brickwork rarely stays damp or saturated for long periods and wicking or excessive moisture is usually from some specific local source. The mottling might well have been due to high room humidity and failing paint from mold than from moisture penetrating the wall (which would result in soft and easy penetrated plasterboard - which also has a quite noticeable smell). In any case that is no longer an issue if installed to the Oz standard - and you're not living there anymore! 
I am not sure who would do it in Sydney, and you might well have to look around a bit - Sydney's mediterranean climate is not as demanding once you have the roof well insulated so fewer people would be having walls done, so fewer installers. The energy efficiency principles still apply though and will reduce heating and cooling needs all year round. Perhaps try the manufacturers first as they often have a list of suppliers & installers - http://www.bradfordinsulation.com.au/home.aspx 
The latest job I have quotes for works out at about $70 an 12.5kg bag installed to a single story residence of around 19 squares which needed 24 bags ($1700) and the cavity was at the wider part of normal though at 170mm (from back of plasterboard to inside face of brickwork). The insulation cost will vary according to the bricked wall area and average cavity depth and the install cost will vary according to ease of access (under windows etc).

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## GraemeCook

Compleat Amateur;  as usual. OldBoss is talking a lot of sense. 
With regard to moisture in your Rental? wall,  such moisture usually gets in from faulty flashing or plumbing (roof or water) or from breach of the dampcourse.   Solution is to identify and fix the cause. 
With installed inwall insulation treated rockwool has the best water resistance and recovery - it really is the prince of insulation.  The installers just drill out a couple of inches of mortar just below the sill and pump in the rockwool - lots of holes as they much access the space between each stud, and if your place has horizontal noggins, even more holes.  When finished they just repoint the mortar. 
A rough rule of thumb for loose rockwool is R=1 per inch of insulation.   With OldBoss's 170mm (about 6.5 inches) he probably has an insulation value around R=6.5 - right up there in the superinsulation category. 
Unless you really want to replace all the internal wall cladding the contractors price will be cost competitive with DIY. 
Good Luck 
Graeme

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## Compleat Amateu

Gents, you've convinced me, sounds like rockwool is the way to go. 
Spoke to CSR/Bradford this morning, they don't have an approved contractor in Sydney who does it, but put me on to one from ACT who does, and comes to Sydney to do jobs.  Price OK, prob about $4k, thumbnail estimate.   So good so far ..... 
In discussion with them (the contractors), we discover a couple more wrinkles:
1.  Process is carried out from 4 tonne truck ("about the size of a removals van");
2.  Max pumping distance 30m from aforesaid truck. 
I have the driveway from hell between road and house, slope about 1 in 2.5 upwards from road, curved, not much turning circle at the top, even for a car.  I've had minicrete trucks and 1 tonne utes up there, don't fancy the idea of a 4 tonner.  Elgas won't drive up it, manhandle gas bottles instead.  You get the idea. 
So I think I'll have to figure out which walls are in 30m range of the street/driveway, and the others ... back to plan A, unfortunately.  Unless someone has another idea? 
Life wasn't meant to be easy ....

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## Bloss

> one from ACT who does, and comes to Sydney to do jobs. .

  If is not them already try JustRite Insulation http://www.justrite.com.au/contacts.html and see if they have the same issue.

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## RJM

Hi CA 
How did your wall insulation project go 
We live in Central Queensland and am thinking of doing same for walls with summer sun in the Morning 
I have read in other websites that where there is wall wrap/sislation installed over the timber frame that bulk insulation should not be in the cavity...it was recommended to be placed in the timber frame ie remove internal lining.  The reason being that the silasation is a radiant heat barrier and having contact with bulk insulation defeats this. 
Did you also look at window treatment..?? 
Cheers  
James M

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