# Forum Home Renovation Structural Renovation  Cold double-brick house problems

## Technetium

Hi Forum, 
We have a 1940's double brick house in Melbourne and although it has ceiling insulation, ducted heating in the roof and a gas heater in the lounge its a struggle to keep warm in winter. 
Is it just the nature of double brick houses to be cold ?- its perfect in summer but cold in winter.. 
Some things we're considering, but need advice on:
We think the ceiling insulation is pretty crap, how can we tell what rating it is, and can we just add extra insulation over the existing to increase the R rating or would it be better to rip out the old and install new? Don't care about rebates or anything, the cold is the issue! 
Is it worth having the cavity between the internal and external brick walls filled? Is there much heat flow from the internal wall into the cavity and is this over-kill in Melbourne? 
The thermal mass of the bricks works for us in summer as it takes days of high temps to heat up but how do we make it work in winter as well? Can we actually pump enough heat into the house to heat the walls up and keep it there for some time without 24x7 heating? 
Any advice appreciated, especially from people dealing with or who have dealt with the same problem.

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## Uncle Bob

Hi, sorry I don't have an old cold double brick house, just a newer cold single brick veneer type. Anyhow, putting a layer of insulation over the existing is the way to go as it adds to the "R" value. 
What floor coverings do you have? Carpet will make a place a lot more snug. If it's just wooden floors maybe insulation underneath may help. 
Hopefully our resident expert on all things construction wise (Bloss) will make an appearance in this thread  :Wink:

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## seriph1

welcome to the forum  -  please take some pics of the home so folks can get a clear idea of its construction  -  I have a contact who is an insulation fanatic (and expert) who may be able to help  -  let me know if you want his number .... just appreciate that he is totally flat out with the govt. rebated ceiling thing right now so may not have time to just give out great deals of info with no sale likely at the other end ...  
Your idea to insulate between the bricks might work well, but I am uncertain how you'd get anything down inside it .... maybe a foam insulation, but Tony will be able to advise what you need I reckon  -  he is in Altona but his guys go all over. 
CONTACT DETAILS: TONY  -  03-93156 975   -  So he knows who to blame, feel free to tell him Steve Ansell from Kilmore referred you  :Biggrin:  :Biggrin:  :Biggrin:  :Biggrin:

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## TermiMonster

This may be a complete red herring, but I would check the sub floor for moisture, can lead to cold.
You can safely add insulation over the existing, in the ceiling space, to increase the R factor.
I would be hesitant to bridge the gap in a double brick wall, myself.
Also, while you down there (sub floor), insulate your floor, or at least check for gaps, etc where draughts can get in, and consider some type of insulation down there.  (Especially if you have no floor coverings).
TM

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## Bloss

sounds like ceiling needs more batts and it checked to make sure it is installed with no gaps - and straight over the top is fine. Check for air gaps in house. Filling double brick cavity can help, but options are limited and expensive. 
Have a look here and do your own audit - then fix what is easiest and cheapest with biggest result for the effort:  http://www.yourhome.gov.au/technical/fs47.html 
and  http://www.yourhome.gov.au/technical/fs48.html

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## GraemeCook

Hi 
A very rough rule of thumb for older insulation is R=0.8 per inch of insulation.   With the current subsidies it might be worth removing the old insulation, replacing with maximum subsidised insulation, and then putting the old stuff back.   Bit of work but you can never have too much insulation. 
Retrofitting wall insulation often works well bur it can be quite expensive - most houses have much more m2 of exterior walls than ceiling area.   Loose fill rock wool is probably the best option, provided you ensure your walls are dry first.   If there is any moisture in the brickwork you should fix this problem first - moisture will really suck heat out of a building, and lead to mold. 
Also, think about double glazing in the main living areas.   The increase in "cosiness" is much greater than the R-value would indicate.  The inside surface of double glazed windows is warm and this eliminates draughts within the room. 
Finally, is your ducted heater throwing the heat down far enough and is it large enough for the job? 
Cheers 
Graeme

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## autogenous

how close are you to other houses?
Sounds like you have a high shadow time on the house?(nothings drying out)

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## Gravy258

I can also recommend tony the Insulation guy in Altona. Go down there and tell him your problem and he'll sort you out. As I've stated before I went to see Tony when it was 42 outside, in his house 21, no A/C. He really is a fanatic. 
-What kind of floor does your house have, exposed timber, tiles or slab?
-How big are the single glazed windows? Are there pelmets fitted to the thick curtains?
-Is the brick exposed or plastered over exposed
-The roof insulation wants to be a mix of bulk and reflective insulation. Top up your bulk with Poly batts from Tony then cover it with some reflective concertina foil batts or two layers of double sided reflective sarking
-Do you have ceiling fans to re circulate the heat ? 
regards 
Paul

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## Technetium

Thanks for the replies guys, 
I'll investigate the moisture problem but we have gone to some lengths to ensure everythings dry down there. The neighbours two-storey blocks most of the winter sun so we have a nice environment for ferns but not much scope for passive heating. 
I'm looking at retrofitting double glazing inserts from Moens glass in Melbourne http://current.moenglass.com.au/products/doubleglazed into the existing cedar frames. 
The tiles roof is very airy and it blows a gale when you're up there. I'm considering using reflective foil or concertina foils batts just keep some of the wind out. They'd also protect the insulation from crud falling from tiles and compressing it. Otherwise there's no reflective insulation. 
Finally Seriph1 and Gravy258, does Tony have a shop in Altona that I could drop in to? I'd like his opinion on which option offers the biggest "Bang-for-Buck"

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## pawnhead

> I'm looking at retrofitting double glazing inserts from Moens glass in Melbourne http://current.moenglass.com.au/products/doubleglazed into the existing cedar frames.

  I just came across this product, and it's obviously not as good as double glazing in many respects, however I'm sure it would give you a lot more 'bang for buck' if you're on a budget; http://www.clearcomfort.com.au/

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## dazzler

Anyone know what the going rate is for supply and install per m2 for r4 ceiling batts?  Is there a standardish price or is it a supply demand thing.

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## ekiec

The air void between the brickwork is in itself the best insulation  available. You say you use gas for heating, gas internally is re-knowned for giving off huge moisture content. This n turn is absorbed into the walls and woodwork. The house cools down overnight and the next day you are trying to heat up a damp house again, this just spirals. Have you found that there is a lot of colds and flu's in the family, also chesty infections- its the damp air. It does not help that your neighbours house shadows you. Agreed - completely remove existing insulation and replace with new high rated (cellulose blown). Look at drying the house out. A great product for this is Solarventi, a solar dehumidifier which not only dries the air but also heats your house at the same time, bringing in clean dry fresh air for free. Further information can be had from www.solarventi.com.au       . There is a shop at 28 Essex Road, Surrey Hills
AU - Victoria 3127  Just ask for Arne or Russell, if you do say Eamon told you...  

> Hi Forum, 
> We have a 1940's double brick house in Melbourne and although it has ceiling insulation, ducted heating in the roof and a gas heater in the lounge its a struggle to keep warm in winter. 
> Is it just the nature of double brick houses to be cold ?- its perfect in summer but cold in winter.. 
> Some things we're considering, but need advice on:
> We think the ceiling insulation is pretty crap, how can we tell what rating it is, and can we just add extra insulation over the existing to increase the R rating or would it be better to rip out the old and install new? Don't care about rebates or anything, the cold is the issue! 
> Is it worth having the cavity between the internal and external brick walls filled? Is there much heat flow from the internal wall into the cavity and is this over-kill in Melbourne? 
> The thermal mass of the bricks works for us in summer as it takes days of high temps to heat up but how do we make it work in winter as well? Can we actually pump enough heat into the house to heat the walls up and keep it there for some time without 24x7 heating? 
> Any advice appreciated, especially from people dealing with or who have dealt with the same problem.

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## GraemeCook

> The air void between the brickwork is in itself the best insulation  available.

  This is true only if you change some basic rules of physics.   A cavity brick wall has an insulation rating around R=0.5 - add 50mm of pumped in rockwool and the insulation will increase to around R=1.7 to 2.0.   

> You say you use gas for heating, gas internally is re-knowned for giving off huge moisture content. This n turn is absorbed into the walls and woodwork. The house cools down overnight and the next day you are trying to heat up a damp house again, this just spirals.

  Good point.   If your gas heater is unflued it will dump an incredible amount of water into the air in the house.   Only solution is to replace that heater.  This does not apply if the heater is flued, unless its installation is seriously wrong. 
Cheers 
Graeme

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## GraemeCook

> Anyone know what the going rate is for supply and install per m2 for r4 ceiling batts?  Is there a standardish price or is it a supply demand thing.

  Around $50-55 per pack which contains 4.5 m2.   Prices vary constantly so you have to sit, observe and wait.   You do not buy in Hobart in early winter, 'cause everyone else does! 
Cheers
.
Graeme

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## barned01

what is the best way to remove the old insulation?
the insulation in our 60's home (yes double brick as well) has blow in insulation in the roof, it is brown and very dusty (like it has broken down)
is there a possibility that disturbing it could be more hazardous to my health than leaving it? I would be happy to go to the effort of removing it and utilising the gov rebate if it was worth my effort and time. But how the heck do you get the old stuff out efficiently, safely and as easily as possible? 
I don't know if Technetium has them but we have pinhole vents in every room of the house. Assuming they are there for a reason (to allow airflow through the cavity wall and stop moisture buildup i would have thought), what are the ramifications of covering those pinhole vents up?

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## rrobor

A lot of old houses had vents high up on the wall to stop condensation, doesnt work but that was the thought then. If you have them block them up as they act as chimneys for heat. Also gaps around windows and doors, the recon the average house has  a foot square gap when all these cracks are added up. So have a good look round, one bad door can cost you half your heat.

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## GraemeCook

> what is the best way to remove the old insulation?
> the insulation in our 60's home (yes double brick as well) has blow in insulation in the roof, it is brown and very dusty (like it has broken down)
> is there a possibility that disturbing it could be more hazardous to my health than leaving it? I would be happy to go to the effort of removing it and utilising the gov rebate if it was worth my effort and time. But how the heck do you get the old stuff out efficiently, safely and as easily as possible?

  Some installers can suck out the old loose fill with an industrial vacuum cleaner - think $600 - 800 for their services.   Hard to do yourself because of the specialised machine needed. 
Do not know about safety of the old insulation - what is it, and has it become contaminated?   But if no inherent problems then it is probably easiest, safest and cheapest to leave it where it is and to cover it with new batts.    
However, government subsidies are not available if the existing insulation exceeds R=0.5, or about 15mm thickness.   Possibly you could argue that the existing stuff has degraded so much that it can no longer be classified as insulation..... but you would really have to find the right bureaucrat in a really good mood. 
Cheers 
Graeme

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## rrobor

There are no advantages to having wall vents. With a double brick house you should have vents outside just above the damp course that will vent the cavity. what your internal wall vents will do is vent hot air from your house. Sure it will help vent moisture from the room as well but the price is at the cost of heating. So if the issue is saving heat in winter they are bad and cost you in heating. For getting rid of heat in summer they work well. So if you have no way to heat or cool your house these will help but so will opening the window or door in summer.

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## Gravy258

Tony operates from his home in Altona Meadows. Its 46 Fitzroy Street South. He's there all day everyday but phone first to tell him your coming. 
He has most products in stock.  
Remember you can never put in too much insulation R4 is the current minimum standard for Melbourne.  
Solar Venti's aren't going to help you if your house is in the shade. I'm sure solar venti's only help the manufacturer.. 
Sounds like your house would be nice and cool in summer. 
cheers 
Gravy

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## MixPhotos

I hear ya Technetium. 
Our house is bloody cold and has zero insulation so far. Built in the 50's doesnt help.  
We have vents in every room on the external walls that we plan to cover up.   *What is the best way to cover the air vents? We were thinking of some ply wood with liquid nails.*  
Cheers 
Mick

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## GraemeCook

> *What is the best way to cover the air vents? We were thinking of some ply wood with liquid nails.*

  
We have vents high up on the internal walls in every room and low down on the external walls of a cavity brick construction. 
On the internal vents. I got up in the ceiling and fixed a sheet of plastic over the inside of each vent with gaffer tape.   Its totally invisible from the rooms and stops all drafts. 
We haven't plugged the external vents yet, but a friend plugged his external vents with builders bag - just squirted it into the holes in the vent - and then painted it when it dried.  We'll probably do the same. 
Cheers 
Graeme

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## MixPhotos

> On the internal vents. I got up in the ceiling and fixed a sheet of plastic over the inside of each vent with gaffer tape.   Its totally invisible from the rooms and stops all drafts. 
> Cheers 
> Graeme

  Hmmmm, might have to give it a go.  :Biggrin:  
I have yet to get into our roof as im not a slender guy (105kg+/5ft 9in) and the man hole looks like a very tight squeeze. Hahahaha.... 
Cheers 
Mick

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## ausdesign

A large proportion of heat loss (with a brick cavity home) is through the walls.
Heating is directly absorbed by the inner skin, transferred to the cavity & then lost to the outside.
The only solution for this (in a new home) is insulation such as a 'foilboard' type product. 
Which ever way you go the cavity still has to retain a break from the outer skin to prevent moisture penetration. Retrofitting insulation is threrefore really not an option to the cavity space.
The lag in heating up the home from outside during summer is due to the warmed air rising through the void in the brickwork. At some point the inner skin is 'overwhelmed' & heat transfer inwards occurs.
Ceiling insulation in southern Vic will optimise out at around R4.1
If there is no floor insulation R2.0 to the subfloor area will help to prevent about 10% heat loss. Usually this is difficult to install due to access.
Large glazing areas can have a big heat loss & are easier to update, altough can be expensive.

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## GraemeCook

> A large proportion of heat loss (with a brick cavity home) is through the walls.
> Heating is directly absorbed by the inner skin, transferred to the cavity & then lost to the outside.
> The only solution for this (in a new home) is insulation such as a 'foilboard' type product. 
> Which ever way you go the cavity still has to retain a break from the outer skin to prevent moisture penetration. Retrofitting insulation is threrefore really not an option to the cavity space.

  
Hi Peter 
You do not like water repellant rockwool loose fill insulation?   Both Vic and ACT governments recommend it, although some councils ban it, and it has become almost the norm in UK which is much damper than most of Australia. 
Cheers 
Graeme

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## ausdesign

No I don't Graeme, but that's a personal choice not based upon any first hand knowledge.
My bigger concern is not so much with capillary action across the fill bit more so with not having a 'vented' cavity to remove air dampness.

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## GrahamC

I'm not too sure what your situation is, but there is currently a huge back order of batts in Sydney. Complements to the Krud's rebate.  :Eek:  
The other thing  is Perth can be really really cold in Winter. It is not like Sydney. I never liked Perth's weather. Give me Sydney's humidity anyday! Get a jumper!  :Wink 1:

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## Gravy258

for blocking off interior vents, just use clear silicon discreetly from insine. You then won't see it from a normal position. Worked for me. 
gravy

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## ekiec

I think you should really look at your gas heater first, I am guessing it's unvented. Thereby a huge amount of moisture is coming from it every hour you use it. This moisture is being absorbed by your brick wall. In turn the next time you want to heat the house the heat is going into the damp walls first before the internal environment gets warm.  It takes a lot more heat to warm damp air than it does dry air. Do not get rid of your vents in the house as you will make the conditions inside the house a lot worse and also find yourself becoming very unwell. These are designed to keep the brickwork and your house dry through ventilation. Block these up and you will get condensation on the internal cavity causing damp, mould and possible rot.We do not know what your budget is, but as you say you are shaded, get your old insulation out and put in new,I would go for 5.0, it does make a difference. Get rid of your non-flued gas heater and get either a flued gas heater, electric low consumption or an ethanol green fire. All these units will help to slowly dry out the house in their process of heating. When the insulation is done I suggest hiring a dehumidifier and use it at both ends of the house for about a fortnight to force dry the structure. Also go around the house and look for water penetration, dripping, leaks, bad gutters etc. get rid of all your fern around the house as they hold huge amounts of moisture which is then transported air bourn to your vents. Trust me if you dry out your house and use 'dry' heaters, you will feel a massive change- in summer and winter.

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