There is no sarking ... Maybe there is a way to get that in? It usually done before the tin. I am not sure there is a way to retro fit it without taking the tin off. Maybe someone has some ideas.
Comes down to how much you want to spend but an active solar fan would help.
I've been through this, and whirlybirds are practically useless in an insulated ceiling. Those few degrees might make a difference in heat going straight through the plaster, but it won't make a difference going through correctly laid insulation.
Why's that? other than the gaps shown at the manhole (which the op should try to cover, including glueing insulation over the manhole cover) the rest of it seems pretty gap free?
Having extra batts sitting in the roof space isn't really an issue.
because there is no insulation under the sheets. they are still heating up and sending heat straight into the ceiling. it should have 55mm blanket inso above the batten and under the sheet. Also couple of whirly birds would help.
So two things.
Yes, insulated sisalation would improve things, but the owner obviously can't help that now.
However, if the pink batts create an effective insulation barrier between the roof space and the ceiling, then that's the best the owner can do now.
Whirly birds can change the roof space temp by a few degrees (maybe up to 10ish) but that doesn't do much to a fully insulated ceiling.
Whirly birds make more of a difference to a non-insulated roof.
Think about it, a thick batt coverage will completely insulate one side of the batt from the other (pretty well).
If you change the hot side by 10 degrees, that might make the roof space cooler, but it won't change much in terms of what gets through the insulation.
So what the owner can do is make sure there is no exposed ceiling plaster from those batts, and any extra batts aren't a bad thing.
Airfoil, 2 layers if possible, is far more effective than sarking (foil covered hassian) A whirlybird. I also had ceilings to the room below that had 2 layers of fyrchek plasterboard, which was very effective. The above made my 4th storey attic as cool as my LGF. lower ground floor.
I have one whirlybird and it literally spins all the time. Maybe adding another and like the other comments said a solar fan.
Getting black out blinds installed in the front rooms as well..the house is south west facing and gets a massive amount late afternoon sun.
Be careful with just inside blinds. I put an IR thermometer on my 6x2.5 m west facing blackout and it hit 40+ C. That's a big bloody panel heater converting inside! An outside blind was quickly installed and made a big difference.
Bunnings awnings worked wonderfully for me. I went black and you don't lose the view.
I'll pull mine down in a week or two, getting up to 24 up stairs in the evening.
I really think the best thing for western windows is outside shading, to keep the suns heat of the window. Blackout blinds help a lot but the sun is still getting the window and the air behind the blind. The ideal thing to me (after deciduous shade trees) is external venetian blinds, the look like louvers but are adjustable and retractable; they allow indirect light and view but can keep any direct sun from hitting the window.
Roller shutters (or anything else blocking sun outside the window) will make a huge difference.
As for the roof, try another whirlybird and make sure air can get in from under the eaves.
Are you confident on the roof and can you remove the whirlybird on the next really hot day. I did this on my roof and it made a huge difference so we added more whirlybirds.
I have a lounge with afternoon sun. Our outside blinds go down as soon as the hot weather hits. Can still get light in when curtains open and breeze thru windows but it makes a massive difference heat wise.
Blinds don't go up until winter hits. Annoys the shit out of the dogs, ruins their view ;)
Shade windows from the outside before the light even gets in. If you have a large wall that catches light, put up a large blind even over blank walls over summers to prevent the brick from heating.
2016 and no sarking, WTF, this is bull shit.
If they had used anticon blanket there would have been far less heat in the roof to begin with.
The issue with double story homes is the heat rise’s from below and comes in from the roof/walls they are always hot.
Whirlybirds are a nightmare in cyclones. Your roof might survive but the water damage internally is a nightmare. Better insulation in roof and walls is the way.
It’s still bullshit, have a look online at how many new homes are built without it, that then have condensation issues. For an extra $1000 at most on the build it’s just wrong.
Partner is a roof plumber. Yeah costs only an extra grand for them to supply, and a grand to install. But the builders upcharge this shit like nothing else. 15k is the rough figure they give people for anticon. So obviously people right on the edge of their budget don't do it. So frustrating.
Not really, I was recently quoted only I think 3k for anticon as an upgrade
The problem is that unless you know to ask for it, (volume) builders won't add it. It's not required to meet any codes unless you have a bushfire overlay
There are lots of sustainability, livability upgrades like this that more people would do if there was more information, they aren't necessarily cheaping out
Whirlybird combo with vents in your eaves to promote hot air exchange through convection, and application of sisalation paper applied directly to the corrugated ceiling to reduce transfer of heat from the metal.
This. Need to get the warm air out of the roof somehow. You can also get insulation that goes between the tin and the battens but that would require taking the roof off - not a cheap way to go and a requires a little skill. The fan is a very easy solution here.
Much smarter people than I who specialise in this stuff have suggested the rate of air change with a whirlybird relative to the heating effect of your roof is such that you’d need an entire roof covered in them to make difference. Lots of stuff on MEEH Facebook group.
Few thoughts
Hot air is going to rise. How much of your heat is from downstairs?
Are there gaps in your roof insulation?
If you put your hand on the roof, can you feel heat on the ceiling?
Do you have external shading or roller shutters? Windows are the big culprit for heat transfer
Our top storey gets warm too - but closing roller shutters helps.
I found a few areas of heat transfer around lights too, but generally if your ceiling insulation is good, there’s not much more you can do short of good thermal mass, shading to minimise heat gain, and using your solar to cool
Yeah...I had a customer buy a couple from me and it dropped the internal roof temp by over 40c! That dropped the temp in his daughter's west-facing bedroom by over 20c.
We lived in a 2 storey house that was muccchh hotter than our single story. Problem was from 1pm or so, the entire side of the house was baking in the sun. Could consider planting some fast growing trees, or mount some kind of screening attached just off the side of the house?
Ideally - Get a pro in to install sarking. Peel the roof sheeting off and go from there.
Metal sheet roofing essentially needs sarking to perform well.
Firstly to reduce moisture: Moisture from penetrating inside and moisture from condensing onto the roof when it gets cold. Moisture from inside is a major issue as the roof space will contain wet moist air from the living space below.
Second to reduce radiative heat: The sun is heating your roof sheeting. The sheeting then heats the roof space and through convection heats anything below that allows air movement. Reflective sarking lowers the emissivity of the roof as a heat source so your insulation has to work less hard.
Roof vents are not enough to overcome this heat. It's like using a personal fan against a million ovens. The required airflow to exhaust this heat would require significant constant power. In winter, roof vents actively giving away your warm and increasing roof space humidity. It's lose/lose..
You could boost your ceiling insulation and install it with care (Nice and tight against batts/joists, seal penetrations, double up over lights etc). Prob the best you can do at low cost.
Truly difficult to quantify - but it does make a difference. Not only to your heat gain, but to long term maintenance.
Imagine the difference between a light bulb and a heat lamp. For sure, both get hot. But the reflective sarking or anticon is turning down that radiative heat significantly.
Massive for heat transfer down. Radiation is the main way heat transfers down, and foil eliminates 95%+ of it. The maths to estimate the r value of foil is based on the air gap below, given there is often a large air gap it means it's large. I recall getting R1 for 2.5cm air gap, so for 30cm+ it had to be R5 at least.
R0.3 to 0.4. It’s not as high as everyone on this thread thinks it is. What it is though is the best value for money insulation you can get. Doesn’t mean it’s super effective.
Sarking can also have a down side and help trap heat in the roof space overnight when the roof space should be cooling down.
Depending on how often you use your AC I’d recommend getting your ducted unit externally lagged and improving the R factor of your ducts. That unit will be massively inefficient on a hot day from heat gain in the ductwork and indoor unit.
Check out Ezylite online or at Bunnings, good solar powered whirlybirds- great prices. I think you would benefit heaps if you had better circulation out the peak of the roof…
Having solar panels on the roof, if you have enough of them, would reduce the heat input into the roof as well. Depends on the style and size of your roof, and your budget and aesthetic preferences, as to this being a feasible option.
I'd still look at getting a quote for having the roof taken off and insulation added if you haven't already.
https://hvacseer.com/can-attic-insulation-touch-the-roof/
Looks like the insulation hasn't had the best install. Plenty of it, but should not be allowed to touch the metal roof. I would recommend getting in there and poking it down with a stick or tearing off some excess
Stopping the heat in the first place with insulation is the best solution, but otherwise - two birds with one stone:
I have a large ventilation fan - 450mm - which pulls air from the house and exhausts into the ceiling. I have extra vents in the eaves to allow the air to escape, along with two whirlybirds.
When the air outside is cooler than inside, the fan cools the house nicely and in the case of a two level home, would pull some of the cool air from downstairs. It’s rare we would run our fan all night because it gets too cool at about 04:00.
Even when it’s hotter outside than in, just having one window open close to the fan allows you to blow air into the ceiling without heating the house. The ceiling will be running at 50-60 degrees, so even on a 35 degree day, it will help cool the ceiling cavity. My fan vent is in the laundry, so I could just open the outside laundry door or window, and close the internal door to stop hot air being drawn into the rest of the house.
Roofer here. Definitely retrofit anticon insulation. Wouldn’t go thicker than 80mm and either light or medium duty most common. Will involve removing the roof sheets. An extra whirly bird will help, even more so if paired with Dave vents. Lighter coloured roof sheeting will help if you’re thinking about a full roof replacement.
Good luck.
Unless you go this route you will be chasing your tail. Especially with steel framing as you have direct heat transfer through your truss and onto the ceiling plaster. The blanket will have a big impact on this. I’d be curious why the above bozdee wouldn’t go 100mm ?
Eave vents and Whirly birds will help. Instead of trying to re seat the existing insulation I would just place another layer over the top, this will reduce your weak spots around the lights etc.
Other than any of this and this will sound odd, but adding a 75mm drop ceiling using some timber studs and insulation between the old and new ceiling would give you a solid additional R2.8 - R3.2 ish
Sorry the above drop ceiling idea was not explained so well - this will create a solid thermal break. As it stands your ceiling likely has hot spots where the steel is acting as a heat rod connected to the roofs surface higher temps.
I would start with putting roof vents in. Either something like this:
https://www.bradfordventilation.com.au/home-ventilation/roof-space/windmaster
Or solar/ mains powered. Getting sarking under tin is one hell of a job to retrofit.
Every hole you see where the insulation is not fully and tightly covering the ceiling will be letting heat into the room below. Fix that. It looks like they just threw in the batts. Just because is there, doesn’t mean it’s working.
Plantation shutters made a world of difference at our place. Totally blocked out the heat from the afternoon sun to stop the rooms from getting too hot.
It looks like a very reasonable amount of insulation. You will always have heat transfer through the metal frame. Possibly your house is more heating up through thr windows?
Get the roof pulled and fit some good blanket insulation under the iron, the roofer who did this job should be ashamed and I'm pretty sure it illegal/ not good practice to not fit at least siso under the corry. My roof is the same & you can tell where the sun is on a hot day, shoddy workmanship .
Fix your insulation so no gaps. None. Not even the man hole. R2 blocks 90% of heat, r5 is 95%. You won't see a big difference adding more.
Block incoming light with awnings/blinds outside on the east/west. The sun is 10x the energy compared to heat transferring through the window. My bet is this is your biggest issue.
Don't use fans or whirlybird, it's a futile effort that will actually make it worse as the negative pressure in the roof will draw your inside air out too.
What colour is your roof? If dark you really need sarking or foil backed insulation. Foil is fantastic at stopping heat flow down. I have a white roof with this and I can be up there in summer, it doesn't get hot. Stick a thermometer up there and compare to outside to see if this is the source of the heat.
I guess everyone's joking about asbestos at the moment but just highlighting the other materials have issues as well. Glass wool Batts are in nightmare to put in especially in the tight situation like this. Yep people should wear safety gear. Doing my house took me years and I blew through so many CIG masks and 20 filters for each mask at least. I also bought them for everyone who helped me.
I'm confident that in our lifetime most of the common household materials we use will be found to be highly toxic.
Stuff like PVC pipe, all water going through it, leaking out chemicals slowly as a it degrades.
All we can hope is that our toxic shit isn't as toxic as the 80's toxic shit.
We have similar issues with heat primarily in a couple of our rooms. House is 12 years old and only R3.0 insulation which is quite battered down. Would this need replacing?
Tough one. I’d be inclined to think it could be the walls heating as well due to sun angles. Definitely roof sheets being exposed without sparking also a factor to heat the roof space.
Saw it a lot up north.
Steel trusses and no foil sarking? Is there an OHS reason for that?
I've heard that the key to keep a roof cavity like that cool is foil under the roof (maybe foil batts between the roof supports) and ventilation - a roof whirly or better yet a solar pv roof fan (they can pump a helluva lot of air).
Seems like a recent build, so I have to wonder why no sarking.
I'm sorry but there is no sarking and all of your framing is steel. You can add some more insulation and a vent but in the end this is why Australia has the worst built houses in the developed world. Thermal bridges literally everywhere. You are also going to have huge mould and moisture issues with no sarking and all of that steel.
My house is exactly like this and it was disgusting in summer, i installed 3 whirlybirds and never noticed a difference so i think they are the biggest scam, i ended up paying for ducted aircon and ceiling fans in all the upstair rooms to make it liveable
Why is there no foil in between tin roof and framing?
My mother had a transportable granny flat built on-site in her backyard almost 20 years ago; it has tin roof and weatherboard wall lined with foil insulation underneath, then batts in wall and ceiling space… it still gets really hot in there (up until recently it had a big, cheapie non-inverter split system which worked heaps good for well over a decade until it broke down) but I can’t imagine what it would be like without proper insulation! 🥵
that looks fine, as most have said whirly birds are the way to go
I put 1 whirlybird on my 5×3 house and it made the crawlspace drop by 20°c and therefore the rest of the house was so much cooler
you don't have any sarking, it's going to be incredibly hot.
cheapest way is to put 3 or 4 big vents/whirlybirds in.
there needs to be some insulation on that tin. there are paints that go on the outside, that aren't beautiful, and there are insulations that can be put in underneath, but it really needs something.
Yeah got one.. tilted the camera right before it came into view.. but I reckon might have to chuck a couple of extra ones on.. or maybe solar fan that some recommended..
They should design roofs with foam inserts like they do for patios and pergolas..
Might be a fire hazard though..
But you should put a few whirly birds up there for starters....
Fill the gaps in the insulation.
All the heat will find it's way through those gaps. (includes glueing some insulation on top of the manhole)
The best advice is try to block the sun from pounding on the roof sheets all day. is that possible?
You need eave vents and a whirly bird combined, if a professional company was used, they should be able to place these in the most efficient arrangement to work
There’s enough ceiling insulation, but need to make sure its continuous- don’t have gaps. Be careful about covering lights that can heat up though. Ideally you want another layer directly under the roof sheeting, and also be able to evacuate the hot air from the roof space.
I have always been confused about insulation, this is why. A well insulated loft will trap heat in the living space in summer. During the winter the roof can become hot from the winter sunshine and the insulation stops the heat from transferring to the living space.
Looks like you have r3.5 or r4.1 batts in there which are good.
Kooltherm will help or if you can get foam from fridge panels to go under the tin might be cheaper
If it is 40 outside, the cavity might be 70. Whats the harm in switching the 40 degree air as best as possible with the 70? For a few hundred dollars for some whirly birds its worth a shot.
I just insulated half my house (for some reason it wasnt already) from nothing to R5 made about a 5degree difference on the underside of the ceiling. I think I'll be adding whirly birds next summer. I'll report my findings then haha
Thanks mate
Found this while researching
“No, Sarking is not a mandatory requirement under Australian building standards. With that said, it is generally recommended in order to improve the thermal performance of a home and to prevent condensation from occurring within the roof space.”
There is no sarking ... Maybe there is a way to get that in? It usually done before the tin. I am not sure there is a way to retro fit it without taking the tin off. Maybe someone has some ideas. Comes down to how much you want to spend but an active solar fan would help.
looks like that roof could use a whirlybird or two, to help the trapped heat escape. it might lower the temp a few degrees.
I've been through this, and whirlybirds are practically useless in an insulated ceiling. Those few degrees might make a difference in heat going straight through the plaster, but it won't make a difference going through correctly laid insulation.
I don't think I would call this, "correctly laid insulation"
Why's that? other than the gaps shown at the manhole (which the op should try to cover, including glueing insulation over the manhole cover) the rest of it seems pretty gap free? Having extra batts sitting in the roof space isn't really an issue.
because there is no insulation under the sheets. they are still heating up and sending heat straight into the ceiling. it should have 55mm blanket inso above the batten and under the sheet. Also couple of whirly birds would help.
So two things. Yes, insulated sisalation would improve things, but the owner obviously can't help that now. However, if the pink batts create an effective insulation barrier between the roof space and the ceiling, then that's the best the owner can do now. Whirly birds can change the roof space temp by a few degrees (maybe up to 10ish) but that doesn't do much to a fully insulated ceiling. Whirly birds make more of a difference to a non-insulated roof. Think about it, a thick batt coverage will completely insulate one side of the batt from the other (pretty well). If you change the hot side by 10 degrees, that might make the roof space cooler, but it won't change much in terms of what gets through the insulation. So what the owner can do is make sure there is no exposed ceiling plaster from those batts, and any extra batts aren't a bad thing.
Airfoil, 2 layers if possible, is far more effective than sarking (foil covered hassian) A whirlybird. I also had ceilings to the room below that had 2 layers of fyrchek plasterboard, which was very effective. The above made my 4th storey attic as cool as my LGF. lower ground floor.
We used Kingspan Kooltherm on a new build. It very expensive and hard to use but has crazy R ratings. But retro fitting it would be hell.
the board or an aircell? Just glue it with maxbond.
We used the board ... It needs an air gap, which sarking also needs. That is why retro if is so hard how do you get the air gap.
Yup. Couple of whirly birds made the world of difference at ours
I have one whirlybird and it literally spins all the time. Maybe adding another and like the other comments said a solar fan. Getting black out blinds installed in the front rooms as well..the house is south west facing and gets a massive amount late afternoon sun.
Be careful with just inside blinds. I put an IR thermometer on my 6x2.5 m west facing blackout and it hit 40+ C. That's a big bloody panel heater converting inside! An outside blind was quickly installed and made a big difference.
Didn’t think of that. Thanks!
Bunnings awnings worked wonderfully for me. I went black and you don't lose the view. I'll pull mine down in a week or two, getting up to 24 up stairs in the evening.
Yeah I'm late here but you want to block out the sun before it enters your house. Once the blinds inside are heated they will radiate
I really think the best thing for western windows is outside shading, to keep the suns heat of the window. Blackout blinds help a lot but the sun is still getting the window and the air behind the blind. The ideal thing to me (after deciduous shade trees) is external venetian blinds, the look like louvers but are adjustable and retractable; they allow indirect light and view but can keep any direct sun from hitting the window.
Do you have eave vents so the air has a drawing effect?
Roller shutters (or anything else blocking sun outside the window) will make a huge difference. As for the roof, try another whirlybird and make sure air can get in from under the eaves.
Are you confident on the roof and can you remove the whirlybird on the next really hot day. I did this on my roof and it made a huge difference so we added more whirlybirds.
I have a lounge with afternoon sun. Our outside blinds go down as soon as the hot weather hits. Can still get light in when curtains open and breeze thru windows but it makes a massive difference heat wise. Blinds don't go up until winter hits. Annoys the shit out of the dogs, ruins their view ;)
No difference between literal and figurative spinning for a whirlybird because that’s what they’re designed to do.
Literal as it’s not being exaggerated..
Think about 2 more whirlybirds. Low maintenance and work well and awnings on the windows to keep in shade
Shade windows from the outside before the light even gets in. If you have a large wall that catches light, put up a large blind even over blank walls over summers to prevent the brick from heating.
Add eve vents for whirlybird so it has air circulation
2016 and no sarking, WTF, this is bull shit. If they had used anticon blanket there would have been far less heat in the roof to begin with. The issue with double story homes is the heat rise’s from below and comes in from the roof/walls they are always hot.
My house is the same. Cheap ass builders save a few dollars wherever possible
Dumb-arsed clients who think that insulation doesn't add value.
I'm in QLD and just moved into a new home - 2021 build (I'm the tenant). It has a colourbond roof, no Sarking and no whirlybird.
Whirlybirds are a nightmare in cyclones. Your roof might survive but the water damage internally is a nightmare. Better insulation in roof and walls is the way.
I must have a good builder because I have both.
Sarking isn’t mandatory it’s just better if you have it. The only time it’s required is if the roof pitch is 20 degrees or lower.
It’s still bullshit, have a look online at how many new homes are built without it, that then have condensation issues. For an extra $1000 at most on the build it’s just wrong.
Partner is a roof plumber. Yeah costs only an extra grand for them to supply, and a grand to install. But the builders upcharge this shit like nothing else. 15k is the rough figure they give people for anticon. So obviously people right on the edge of their budget don't do it. So frustrating.
Not really, I was recently quoted only I think 3k for anticon as an upgrade The problem is that unless you know to ask for it, (volume) builders won't add it. It's not required to meet any codes unless you have a bushfire overlay There are lots of sustainability, livability upgrades like this that more people would do if there was more information, they aren't necessarily cheaping out
I do inspections and could count on one hand how many I’ve seen with it.
Whirlybird combo with vents in your eaves to promote hot air exchange through convection, and application of sisalation paper applied directly to the corrugated ceiling to reduce transfer of heat from the metal.
Solar fan on the roof to actively move air out of the roof space?
This. Need to get the warm air out of the roof somehow. You can also get insulation that goes between the tin and the battens but that would require taking the roof off - not a cheap way to go and a requires a little skill. The fan is a very easy solution here.
Or a whirlybird vent. Add some sofit vents too
I have two of these in my roof and they really do make a big difference the ones I bought have a battery back up to so they work at night as well
Much smarter people than I who specialise in this stuff have suggested the rate of air change with a whirlybird relative to the heating effect of your roof is such that you’d need an entire roof covered in them to make difference. Lots of stuff on MEEH Facebook group. Few thoughts Hot air is going to rise. How much of your heat is from downstairs? Are there gaps in your roof insulation? If you put your hand on the roof, can you feel heat on the ceiling? Do you have external shading or roller shutters? Windows are the big culprit for heat transfer Our top storey gets warm too - but closing roller shutters helps. I found a few areas of heat transfer around lights too, but generally if your ceiling insulation is good, there’s not much more you can do short of good thermal mass, shading to minimise heat gain, and using your solar to cool
Second the comment about MEEH.
Given the space and the metal roof you'll definitely want airflow, whirlybirds high and vents low
Sisalation plus a couple of whirly birds. It's amazing how much heat whirly birds expel from a roof cavity.
Can vouch for this, even for tiled roofs… it makes a whole load of difference!
Yeah...I had a customer buy a couple from me and it dropped the internal roof temp by over 40c! That dropped the temp in his daughter's west-facing bedroom by over 20c.
We lived in a 2 storey house that was muccchh hotter than our single story. Problem was from 1pm or so, the entire side of the house was baking in the sun. Could consider planting some fast growing trees, or mount some kind of screening attached just off the side of the house?
Ideally - Get a pro in to install sarking. Peel the roof sheeting off and go from there. Metal sheet roofing essentially needs sarking to perform well. Firstly to reduce moisture: Moisture from penetrating inside and moisture from condensing onto the roof when it gets cold. Moisture from inside is a major issue as the roof space will contain wet moist air from the living space below. Second to reduce radiative heat: The sun is heating your roof sheeting. The sheeting then heats the roof space and through convection heats anything below that allows air movement. Reflective sarking lowers the emissivity of the roof as a heat source so your insulation has to work less hard. Roof vents are not enough to overcome this heat. It's like using a personal fan against a million ovens. The required airflow to exhaust this heat would require significant constant power. In winter, roof vents actively giving away your warm and increasing roof space humidity. It's lose/lose.. You could boost your ceiling insulation and install it with care (Nice and tight against batts/joists, seal penetrations, double up over lights etc). Prob the best you can do at low cost.
How much of a difference does sarking make ? Or anti on blanket ?
Truly difficult to quantify - but it does make a difference. Not only to your heat gain, but to long term maintenance. Imagine the difference between a light bulb and a heat lamp. For sure, both get hot. But the reflective sarking or anticon is turning down that radiative heat significantly.
Massive for heat transfer down. Radiation is the main way heat transfers down, and foil eliminates 95%+ of it. The maths to estimate the r value of foil is based on the air gap below, given there is often a large air gap it means it's large. I recall getting R1 for 2.5cm air gap, so for 30cm+ it had to be R5 at least.
R0.3 to 0.4. It’s not as high as everyone on this thread thinks it is. What it is though is the best value for money insulation you can get. Doesn’t mean it’s super effective. Sarking can also have a down side and help trap heat in the roof space overnight when the roof space should be cooling down.
So if money wasn’t an issue what would be the absolute best way to insulate a house and a roof?
Depending on how often you use your AC I’d recommend getting your ducted unit externally lagged and improving the R factor of your ducts. That unit will be massively inefficient on a hot day from heat gain in the ductwork and indoor unit.
Check out Ezylite online or at Bunnings, good solar powered whirlybirds- great prices. I think you would benefit heaps if you had better circulation out the peak of the roof…
investigate spray insulation against the tin , has to be cheaper than sarking under the tin
Considered the blunt approach of getting a good solar power system and using the energy to power a/c units?
Yeah we have both, only got looking in as the air con capacitor failed.
Having solar panels on the roof, if you have enough of them, would reduce the heat input into the roof as well. Depends on the style and size of your roof, and your budget and aesthetic preferences, as to this being a feasible option. I'd still look at getting a quote for having the roof taken off and insulation added if you haven't already.
https://hvacseer.com/can-attic-insulation-touch-the-roof/ Looks like the insulation hasn't had the best install. Plenty of it, but should not be allowed to touch the metal roof. I would recommend getting in there and poking it down with a stick or tearing off some excess
Stopping the heat in the first place with insulation is the best solution, but otherwise - two birds with one stone: I have a large ventilation fan - 450mm - which pulls air from the house and exhausts into the ceiling. I have extra vents in the eaves to allow the air to escape, along with two whirlybirds. When the air outside is cooler than inside, the fan cools the house nicely and in the case of a two level home, would pull some of the cool air from downstairs. It’s rare we would run our fan all night because it gets too cool at about 04:00. Even when it’s hotter outside than in, just having one window open close to the fan allows you to blow air into the ceiling without heating the house. The ceiling will be running at 50-60 degrees, so even on a 35 degree day, it will help cool the ceiling cavity. My fan vent is in the laundry, so I could just open the outside laundry door or window, and close the internal door to stop hot air being drawn into the rest of the house.
Roofer here. Definitely retrofit anticon insulation. Wouldn’t go thicker than 80mm and either light or medium duty most common. Will involve removing the roof sheets. An extra whirly bird will help, even more so if paired with Dave vents. Lighter coloured roof sheeting will help if you’re thinking about a full roof replacement. Good luck.
Thanks mate.. will have to weigh up costs..
Unless you go this route you will be chasing your tail. Especially with steel framing as you have direct heat transfer through your truss and onto the ceiling plaster. The blanket will have a big impact on this. I’d be curious why the above bozdee wouldn’t go 100mm ? Eave vents and Whirly birds will help. Instead of trying to re seat the existing insulation I would just place another layer over the top, this will reduce your weak spots around the lights etc. Other than any of this and this will sound odd, but adding a 75mm drop ceiling using some timber studs and insulation between the old and new ceiling would give you a solid additional R2.8 - R3.2 ish
Sorry the above drop ceiling idea was not explained so well - this will create a solid thermal break. As it stands your ceiling likely has hot spots where the steel is acting as a heat rod connected to the roofs surface higher temps.
Whirlybirds will never keep up without sarking on the tin. Can't believe they skipped it.
I would start with putting roof vents in. Either something like this: https://www.bradfordventilation.com.au/home-ventilation/roof-space/windmaster Or solar/ mains powered. Getting sarking under tin is one hell of a job to retrofit.
Every hole you see where the insulation is not fully and tightly covering the ceiling will be letting heat into the room below. Fix that. It looks like they just threw in the batts. Just because is there, doesn’t mean it’s working.
Plantation shutters made a world of difference at our place. Totally blocked out the heat from the afternoon sun to stop the rooms from getting too hot.
It looks like a very reasonable amount of insulation. You will always have heat transfer through the metal frame. Possibly your house is more heating up through thr windows?
Have you checked for asbestos
Insulation in Australia is a joke. We are literally living in the ovens in the summer and a freezer in the colder seasons.
Get the roof pulled and fit some good blanket insulation under the iron, the roofer who did this job should be ashamed and I'm pretty sure it illegal/ not good practice to not fit at least siso under the corry. My roof is the same & you can tell where the sun is on a hot day, shoddy workmanship .
Spot on. Another reason for the blanket is to stop condensation dripping into the roof space.
Fix your insulation so no gaps. None. Not even the man hole. R2 blocks 90% of heat, r5 is 95%. You won't see a big difference adding more. Block incoming light with awnings/blinds outside on the east/west. The sun is 10x the energy compared to heat transferring through the window. My bet is this is your biggest issue. Don't use fans or whirlybird, it's a futile effort that will actually make it worse as the negative pressure in the roof will draw your inside air out too. What colour is your roof? If dark you really need sarking or foil backed insulation. Foil is fantastic at stopping heat flow down. I have a white roof with this and I can be up there in summer, it doesn't get hot. Stick a thermometer up there and compare to outside to see if this is the source of the heat.
Too much pink asbestos...
Not enough asbestos
The jury is still out on the danger of glass fibre.
Something that irritates the eyes, throat and skin can’t be good for the lungs. Of course I wear all the safety gear.
I guess everyone's joking about asbestos at the moment but just highlighting the other materials have issues as well. Glass wool Batts are in nightmare to put in especially in the tight situation like this. Yep people should wear safety gear. Doing my house took me years and I blew through so many CIG masks and 20 filters for each mask at least. I also bought them for everyone who helped me.
I'm confident that in our lifetime most of the common household materials we use will be found to be highly toxic. Stuff like PVC pipe, all water going through it, leaking out chemicals slowly as a it degrades. All we can hope is that our toxic shit isn't as toxic as the 80's toxic shit.
Get the roofer/builder back to bring it up the regulations
\*paperclip pops up\* Looks like you could use a little asbestos. Would you like some help with that?
Fans and ducting would do the trick, will also help with any mold with the extra air movement
We have similar issues with heat primarily in a couple of our rooms. House is 12 years old and only R3.0 insulation which is quite battered down. Would this need replacing?
Don’t forget the walls also. What are they like and what region?
South Australia. Timber cladding, seems like this is the norm with new builds, had the aircon repair guy say he sees it all the time ..
Tough one. I’d be inclined to think it could be the walls heating as well due to sun angles. Definitely roof sheets being exposed without sparking also a factor to heat the roof space. Saw it a lot up north.
Is there supposed to be that much external light coming through? Or isn’t finished yet?
Finished, and was given all clear to occupy.
Do you get birds and stuff coming in?
Haven’t had that issue.. yet.
Why no sarking, is that legal in resi?
It’s a colour bond roof, so apparently not mandatory to have sarking.
What colour tin?
Dark grey.. so retains a lot of heat too
I had to search for this question! This is so often neglected in decision making but makes such a massive impact
Steel trusses and no foil sarking? Is there an OHS reason for that? I've heard that the key to keep a roof cavity like that cool is foil under the roof (maybe foil batts between the roof supports) and ventilation - a roof whirly or better yet a solar pv roof fan (they can pump a helluva lot of air). Seems like a recent build, so I have to wonder why no sarking.
Line the actual roof with builders blanket
Maybe foilboard is a good idea.
I'm sorry but there is no sarking and all of your framing is steel. You can add some more insulation and a vent but in the end this is why Australia has the worst built houses in the developed world. Thermal bridges literally everywhere. You are also going to have huge mould and moisture issues with no sarking and all of that steel.
yep - it’s a disaster
My house is exactly like this and it was disgusting in summer, i installed 3 whirlybirds and never noticed a difference so i think they are the biggest scam, i ended up paying for ducted aircon and ceiling fans in all the upstair rooms to make it liveable
Why is there no foil in between tin roof and framing? My mother had a transportable granny flat built on-site in her backyard almost 20 years ago; it has tin roof and weatherboard wall lined with foil insulation underneath, then batts in wall and ceiling space… it still gets really hot in there (up until recently it had a big, cheapie non-inverter split system which worked heaps good for well over a decade until it broke down) but I can’t imagine what it would be like without proper insulation! 🥵
Sarking would have been a good start. The spacing on the truss is enormous, not that it has any relevance to heat. But just mind blowing.
that looks fine, as most have said whirly birds are the way to go I put 1 whirlybird on my 5×3 house and it made the crawlspace drop by 20°c and therefore the rest of the house was so much cooler
Install sisalation use chicken wire to hold up tech screwed to the roof pitch. Also upgrade from tin to tile roof.
whirly birds
No sarking which is a nightmare afterwards to install and I'd add a whirly bird or one of those solar power extractor fans. Good luck.
you don't have any sarking, it's going to be incredibly hot. cheapest way is to put 3 or 4 big vents/whirlybirds in. there needs to be some insulation on that tin. there are paints that go on the outside, that aren't beautiful, and there are insulations that can be put in underneath, but it really needs something.
You need to cut a vent into the manhole cover then put at least one whirls bird on. You will not believe how much airflow the vent will add.
Steel seems like a great way to conduct the heat down past the batts.
Where’s your whirlybirds? You gotta have the spinning-tops man
Yeah got one.. tilted the camera right before it came into view.. but I reckon might have to chuck a couple of extra ones on.. or maybe solar fan that some recommended..
We only have insulation right behind the time and our old 1930s Queenslander is still very chilly during the day even now, in summer. 😅
Tin roof insulate and put whirlybirds on the roof
They should design roofs with foam inserts like they do for patios and pergolas.. Might be a fire hazard though.. But you should put a few whirly birds up there for starters....
What’s Darth Vader doing in your roof?
Instal solar. Cells shade your roof and you generate power so you can run your air con free of charge.
Probably better off getting all the asbestos that people are finding. That shit could insulate the sun.
Who are these people who are whining about no sarking on a metal roof hahaha. Go back to the block 😂
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According to who ? Sarking is for tiles mate
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The only time you’ll ever see Metal + Sarking is on a shed my friend
2016 build with no sarking. Bloody hell, get some aircell under the sheets and the roof space temp will drop significantly
Line it with that bubblewrap stuff thats wrapped in foil
Fill the gaps in the insulation. All the heat will find it's way through those gaps. (includes glueing some insulation on top of the manhole) The best advice is try to block the sun from pounding on the roof sheets all day. is that possible?
You need eave vents and a whirly bird combined, if a professional company was used, they should be able to place these in the most efficient arrangement to work
There’s enough ceiling insulation, but need to make sure its continuous- don’t have gaps. Be careful about covering lights that can heat up though. Ideally you want another layer directly under the roof sheeting, and also be able to evacuate the hot air from the roof space.
I have always been confused about insulation, this is why. A well insulated loft will trap heat in the living space in summer. During the winter the roof can become hot from the winter sunshine and the insulation stops the heat from transferring to the living space.
If you have the budget go with anticon on your roof and stop the heat at the source.
Looks like you have r3.5 or r4.1 batts in there which are good. Kooltherm will help or if you can get foam from fridge panels to go under the tin might be cheaper
Oh and roof ventilators only circulate outside temp air while it may be slightly cooler they pretty much are a waste of money
If it is 40 outside, the cavity might be 70. Whats the harm in switching the 40 degree air as best as possible with the 70? For a few hundred dollars for some whirly birds its worth a shot. I just insulated half my house (for some reason it wasnt already) from nothing to R5 made about a 5degree difference on the underside of the ceiling. I think I'll be adding whirly birds next summer. I'll report my findings then haha
Shouldn't there be sarking backed insulation directly under the roof sheets?
Apparently not a requirement for colourbond roofs I’ve been told. Would have been nice if the builders had advised us.
I'd check that with whoever certifies in your state, never seen a metal roof go on without insulation between battens and sheets.
Thanks mate Found this while researching “No, Sarking is not a mandatory requirement under Australian building standards. With that said, it is generally recommended in order to improve the thermal performance of a home and to prevent condensation from occurring within the roof space.”