Tile or Iron Roof Which is better?
What Type of Roof do I have on my house and How can I insulate it ?
If you ever wanted to know what type of roof you have, then this is the page for you. I have personally been on 1000's of roofs and this page has photos, video links and Descriptions of all common roofing material types and there most common Construction type. Roofs are sometimes hard to identify and many times I have had customers who are confused about the type of roof they have and its Pros or Cons. Below you will find my opinion as a roofer for 30 years experience about all kinds of roofs.
Common Basic Roof Material Types
Above is a Corrugated Iron Roof and it is easily Identified by the corrugations in the iron. There are many variations of this type of roofing material that are basically the same but they do serve slightly different purposes.
This roofing material is commonly used in the following roof Construction types.
Wrap over iron roof
Flat roofs (Normally Clip Lok)
A Frame or Snow Roofs
Above is a Cement Tile roof, Tiles can be made in a number of different materials and moulded profiles including
TerraCotta Tile (Natural Clay Tiles)
Metal Tiles -Normally Aluminium
Tiles make a very attractive roof finish and depending on the material they are commonly found on pitched roofs where the angle is greater than 20 degrees.
Tile Roofs allow for greater airflow in the roof that a iron roof and so are naturally cooler in hot environments.
Clay roof tiles (Terracotta) will last forever and look great with very little maintenance.
Above is a Asbestos roof, this roof type contains the Dangerous asbestos fibres and these are band from use in most Developed nations. If you have this type of roof on your house it will probably last form many years yet but it is recommended that you replace it as soon as you can afford to.
This type of roof normally comes in the "Super 6" variation that has a 6 inch Corrugation but it also has a Mini orb variation that is much less common. This has Corrugations or about 3 inches.
It is Very common for Asbestos roofs to be unpainted like the one above but often people do paint them to try and improve their appearance. If they are unpainted, asbestos roofs all have this distinctive mouldy black and white cover.
Do not collect drinking water from these roofs or try to cut the sheets to fit roof vents or skylights.
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Corrugated Iron Roof
Metal or corrugated iron roofs have distinctive corrugations about 50mm from point to point. These are often fixed down with lead head nails, if they are older or screws on the modern Color Bond ones.
They have three distinctive giveaways that can be easily spotted with the naked eye.
Corrugations about 50mm in length.
Notice if they have screws or lead head nails to fix them down.
As the roof ages it may develop rust and this rust will normally start at the nail holes on the bottom of the roof sheets or between the laps of two overlapping sheets.
TrimDek Rolled Iron Roof, these sheets are near impossible to get back in if you pull one out. The bigger the curve the harder they are to get back in.
Normal corrugated iron or Zinc Alum coated iron roof. This is a photo of the ridge cap on a iron roof, this flashing is fixed with steel rivets and you can see they are starting to rust
Great example of how every cut in a iron roof or place that can hold water will eventually turn into a big rust hole. This is a lead head nail on a roof that is causing the sheet to rust and should be replaced with a screw that has a neon washer
A Metal roof will hold up very well in all kinds of weather and they are very water proof. These roof do look good and the older ones that are made from thicker steel sheets that have been Zinc coated can easily last for 100 years but the newer ones unfortunately are not made to last longer than the paint job....
Iron roofs are cheap to buy and light, so the structure they are fixed to does not need to have as much timber in it. This could be good or bad depending on your perspective. These roofs are quite air tight and do not get much dust in them from the outside unless it is a old Queenslander with open eaves.
A cheap roofing material that can be fixed to light construction roofs like Exposed beam or Raked roofs. They have superior water proofing at low angles when compared to other materials like tiles. For this reason corrugated iron can be used on very low pitch or even flat roofs.
All Iron roofs suffer from the effects of age, anywhere the protective coating is removed they will rust in that spot, that means every screw hole or cut in the sheet is the start of a rust hole in the future.
These don't often kink when walked on but it can happen, especially if iron is rolled into a "Bull Nose", these often lack support under them and will kink if walked on.
They will dint in a hail storm and although replacing a sheet is a simple matter, the colour of the new sheet will not match the colour of the old faded sheet and so you roof may need to be repainted anyway.
Rain noise is a very big problem if your iron roof is not well insulated and so I really recommend having good insulation on your ceiling if you have an iron roof. Also iron roofs expand and contract in the heating and cooling of the day, this can make a creaking noise that is quite loud if the temperature changes quickly. Any noise in a iron roof will reflect around inside the roof space a lot more than in a tile roof and so Ceiling insulation is more important when considering this cheaper type of roof.
Condensation will also form on the bottom side of a roof at time but I do not normally see this as causing any trouble as the water will evaporate very quickly as the day heats up.
Iron roofs Get hotter faster and hold the heat longer than tile roofs, I always hated climbing into a iron roof at 3pm in summer because I know that it will be very hot in there even if they have roof vents (The exception to this is old Queenslanders with open eaves but then these roofs are freezing in winter.
If you live close to the sea these roofs do not like the salt air and will not last as long as a tile roof. Especially if they have a join in the sheet from the top of the roof to the bottom. The join will hold moisture and rust the laps of the sheet out from the inside. You will not be able to see this from inside the roof or from outside the roof and then one day it will just start to leak (Especially after someone walks on the joint and cracks the rust loose.
If you are building with Iron and thinking about insulation (Which is a Must) you should not waste your money on ventilation or anticon blanket. A good insulation installed on the ceiling will do the job very well but roof vents will just cause future roof leaks, make noise and let critters into your roof. Roof vents do not move enough heat to cool these roofs and so don't waste your money.
Anything at all left on the roof will encourage rust to form, if you have one of these roofs check it for leftover nails, screws or rubbish left on the roof anytime you have a tradesman on the roof. Often you will find old screws on a roof like these that have been left there from the original installers and it will be causing a rust hole to form around the screw. This happens because anything laying on a roof holds water around it for longer.
Tile roofs have a square type patterns on them and a ridge cap at the top which is cemented into place. They come in many different profiles and are normally either made from Cement, Terracotta or less commonly slate.
The roof on the right is a Terracotta Tile Roof and they have never been painted, this makes Terracotta one of the most environmentally friendly roofing solutions.
You will find all kinds of shapes for roof tiles and the are either fixed to the roof by wire on the bottom side, nails in the overlap or steel tile clips.
Unfortunately some trades people do not know how to change a roof tile but it is easy to do and takes about 30 seconds. If you have silicon on a roof tile it is a temporary repair and should be replaced.
This is what cheap cement tiles look like when all the paint wears off them, just covered in mould. Because cement is porous the tile absorbs water every day and becomes more and more brittle until they break under any pressure.
The ridge cap bedding on a tile roof will degrade over time if it is not sealed with a good flexible pointing like FlexiPoint. I recommend you use a acrylic pointing to water proof the bedding and allow for movement without cracking.
This is how we can insulate a Raked tile roof area, even though there is no manhole. We just slide up the tiles we need to get access to the raked area that is only about 150mm deep and then pump Loose fill insulation into each bay
Tiles have been used for 1000's of years on roofs and they actually make a excellent roof with some fantastic properties that no other roofing material has been able to match. Tiles can be made out of may materials but Clay tiles are by far the best and longest lasting material to make your roof out of. Clay tiles are made from natural clay deposits, that are moulded and baked, it's that simple. They are so environmentally friendly when compared to other materials and they look fantastic with a nice coloured glazing on them (The colour comes from minerals added before baking, not chemical paints added after). A good clay tile will literally last forever.
Tile allow a roof to breath and that helps stop excess heat building up in your roof space, this means you do not need as much insulation as you would with a iron roof.
Tiles also help stop sound as they absorb the sound much more than an iron roof does and tile roofs do not creak and groan as the tile expands and contracts in the changing temperature.
If one of your natural clay (Terracotta Tiles) breaks it is a simple thing to remove the broken tile and replace it with a new one. If you went with the natural clay tile the colour will not have faded and so the new tile will match perfectly (Aside from the fact that the new tile will be a lot cleaner) This is a big advantage over cement tiles that fade and become brittle on your roof over time. Then it just takes one hail storm of a careless tradesman to break a few tiles and you will not be able to match the colour with the new tile, which normally means repainting the roof.
Roof access for trades people doing work is very easy, two tiles can be lifted out in no time allowing easy non destructive access. If a trades person breaks a tile it is normally obvious and can be temporarily fixed with silicon or a replaced with a spare tile.
The Bedding is the weakest part of a tile roof and it will need to be checked after about 30 years but if it has a quality Acrylic coating over it that is flexible, it should last a lot longer. In fact if the pointing is applied to the bedding properly it may need to be repointed but it should never need to be re bedded.
Cement tiles do not last forever, in fact they are not designed to last much longer than the coating that is put on top of them. Cement tiles will crack without people even walking on them, sometimes the roof tiles just develop a crack which will open up over time and start to leak. I have seen many brand new roof with these cheap crappy cement tiles on them that are already broken.
Cement Tiles really are cheap for a reason, normally they are put on the roof still green (Not properly cured) and they will break and leak at some point in the life of your home, this could cause a lot of damage particularly if the leak runs down a wall cavity and rots out the wall timber frame before you notice it is leaking. I have seen that happen a 100 times. Save yourself the problems and just pay the extra for Natural Clay or Terracotta tiles when you buy your new home. In 30 years of doing roof work I can not even remember the last time I broke a terracotta tile or even saw one broken on a roof. They are that good.
Every new house normally gets a few spare tiles with it from new But you will need to make sure you get at least 30 spares in my opinion. This gives you a good margin if a tradesman breaks a few tiles. If you have Terracotta tiles you most likely will not need any spares but all the same a few could not hurt.
If you are getting your cement tile roof restored, don't get suckered into replacing "tile clips" on your roof. I have seen people being told by scamming roof companies that their roof is leaking because of old tile clips and being quote $5000 for the repair. The lady called me and I found one broken tile and a blocked valley witch I fixed for free when I installed her roof insulation that only cost $2000. Tile clips are a common scam by doggy roofing companies and so please send me a message if you have any doubt before you pay to have them repaired or replaced.
If you buy cement tiles or have your roof painted, it is a good idea to leave your spare tiles in a place where at least a few of them will weather the same as the ones on the roof do. That way if a trades person breaks one it will have about the same faded colour to when you get it replaced. Saving you seeing the new tiles standing out like a saw thumb every time you drive in the driveway.
If a trades person gets on your roof, get up and check your tiles over as soon as you can, most trades will break tiles because they do not know how to walk on a tile roof properly. Often then just silicon them up or put the broken tile in the eave area. Pretending that they did not break it and then when your eave rots out they can say that the work they did was nowhere near that broken tile. So check before they go. Of course if you have terracotta tiles, it is really unlikely they will break one in my experience.
If you have "valleys" in your tile roof Keep them clean because leaf litter will build up in them and rust the valley iron out. If you have lots of trees around invest in a quality gutter protection that is made of aluminium (don't use the plastic crap, it does not work 1/2 as well)
Asbestos roofs are almost never painted from new and so like the one on the right they end up covered in a black mould. Normally asbestos was used on small roofs up to 120 square meters with gable ends. They can be identified by a corrugation that is normally 6 inches wide but there is a less common profile that is 3 inches wide.
The low pitch and the black mould makes these roofs extremely hot in summer time.
Notice my 2 youngest sons working with me when they were still at school to insulate this asbestos roof while in their Comfort Zone Insulation uniforms.
Their is no benefit to having one of these roofs on your house over any other product and so the only benefit is that it keeps the water out of your home. While it is doing that, you are doing well, if the sheets ever break of you want to paint it, save your money up and replace the roof.
Asbestos is a banned product in Australia and can no longer be used because the fibres get into your lungs and cause cancer. If you have it on your roof now do not collect water from your roof for drinking and make sure you do not get exposed to loose fibres from it.
These roofs are very hot in summer and we can lift sheet to insulate under them with pump in cellulose fibre roof insulation. Even if it does not have a manhole we can still insulate under them by lifting a sheet. The sheets are very brittle and can not be replaced, so I would not recommend anyone to move them unless they have done 1000's of them before like I have.
The fibro sheets are very heavy and should be handled by two people if they need to be moved. The cost of asbestos disposal in Australia is very high and so you might want to sell the house if you think the sheets need replacing.
Definitely do not sand, grind or cut these sheet. That mean you can not put a roof vent in the top because you would have to cut a hole and this would expose the person doing it to dangerous asbestos fibres.
If you have a leak in one of these roofs it will most commonly be the ridge caps that are cracked or the screws in the sheet have started to leak. Originally the screws have a tar put on them to seal them but it dryes out and cracks over time. You can repair it with silicon but it is actually better to use more tar because the tar is soft and in the heat rebinds to the asbestos every day but silicon will just come off with the top layer of fibres.
Metal Tile Roof
Metal tiles are often covered in small stone and have a rough finish that hides the nails in the front edge of the tile and the joins.
They have three distinctive giveaways that can be easily spotted with the naked eye.
A square ridge profile at the top of the roof
Notice the little kink in the front of the tiles from pressing the metal
The line down the middle of about every 3rd tile where the metal sheet overlaps the next tile.
Kinked Metal Tile Caused by not walking on the front edge, Follow this link to learn how to fix damaged metal tiles.
Notice the square ridge cap that is a tell tail sign to easily spot metal tiles
Metal tiles come in length from 4 to 7 "pans" (the curved part) and to get one out to be replaced requires removing the nails in all adjoining tiles above and beside it
They are made from light weight aluminium and nailed to the batten with 4 nails in the front edge of them. This makes them quite waterproof and good in storms. The stone covering is not just for show but also helps to deaden the noise of rain on the roof, that is a real problem with metal roofs.
These tiles do not wear out but the stone covering often washes off or turns a dark brown or black colour as they age and get covered in mould. Often this will expose the shinny aluminium and leave the stones build up in the guttering.
These tiles are made from aluminium and are good until someone walks on your roof who does not know how to walk on metal tiles because most people will walk in the middle of the tile and kink them. When they kink, they often open up little tears that will leak.
If you need to walk on your roof you should always walk on the front edge of the tile and have all your weight on that 50mm wide strip that is supported by the batten underneath. If you have kinked metal tiles watch this video about how to fix them, it is from the manufacturer and they make it look easy but I can tell you it is not that easy and once they are kinked once they will kink in that same place again more easily. Also this video does not show the little tears that can form with a bad kink but I often see them on the inside or the tile.
If you want to paint them you need to pressure clean the loose stones off first and then apply the new paint and additional chips where they are worn off.
I do not recommend you letting any tradesman on your roof it you have a roof like this, most trades will tell you they know all about it but in the end if your roof does not leak now and you let people on your roof, it will most likely start leaking.
Roof Construction Type
The drawing on the right describes a "Hip" end on the roof. This roof has 3 hip ends and the hips are the lines running from the corners up to the ridge.
The bits in yellow on the drawing to the right are the "Gable" ends of the roof. Often these gables are vented to allow better air circulation in a roof but a good quality ceiling insulation like the Cellulose Fibre pumped in product is a better solution than venting the gable ends.
The Typical Queenslander on the right has a iron roof and big vented eaves up the left side of the roof that allow lots of roof ventilation. It also has a "Bull Nose Veranda roof" that is rolled iron and can not be lifted. That means the only way to insulate the enclosed veranda at the front of the house is to make a manhole in the ceiling inside and pump cellulose fibre insulation into the cavity. It is a waste of time insulating the main roof unless you do the veranda because the heat coming in the veranda will just rise into the main house and actually be trapped under the insulation in the main roof section.
This is a example of how insulating part of a home may actually make the home hotter than it was before.
Wrap Over Iron
The wrap over iron roof on the right is one sheet of corrugated iron that runs from one side of the roof to the other over the crest. It does not have a ridge cap in the middle of the sheet.
These roofs get very hot but most insulation companies have no idea how to get these long roof sheets back into place after removing them and so they just tell customers that they can not be insulated. As you can see though we have insulated this roof with cellulose fibre pump in insulation and it works really well for somer and winter.
Flat Clip Lock Roof
Clip Lok roofing is great for flat or nearly flat areas of roof that need to be covered. I often find a small bit of clip lock roofing at the back of a house or on a shed.
These are very hot roofs because they are so flat and have very little air movement inside them. It is a big job but these roofs can be easily lifted and insulated. It is difficult not to kink the sheets as you are lifting them but not impossible. The more modern color bond version of this roof profile is impossible to lift without getting at least some kinks in the sheets in my opinion (just because it is made from such thin steel now).
Raked Roof or Skillion roof
A skillion roof or raked roof is where the ceiling inside the home is at the same angle as the roof line as in the diagram to the right. Often this is a built in veranda that has been made into a kitchen or bathroom extension.
There is only about 150mm of cavity space in a raked roof area but that is plenty for comfort zone insulation to lift the roof and pump cellulose fibre insulation into it. There is no point in insulating the rest of the home if you do not include attached roof areas like this.
Exposed Beam Roof
A exposed beam ceiling might have a Iron or tile roof on the top but from the inside it will look similar to these two pictures. Most people think that there is absolutely no space in one of these roofs to put any insulation into but there is actually a gap of at least 40 mm under the roofing. Here at Comfort Zone insulation we have made a special tool to put into this gap that allows us to insulate these exposed beam roofs by pumping cellulose fibre insulation into them.
So if you have a exposed beam roof and you house is really hot in summer we can help.
If only part of your house is Exposed beam or raked, you will almost certainly have a in ceiling wall or bulk head that must be included when insulating the ceiling. If you do not get the in ceiling wall done with some quality insulation batts the heat in the main roof cavity will continue to heat into your home and ruin any chance you had of having the rest of your insulation work.
"A" Frame or Snow Roof
This type of snow roof or "A Frame" roof is not very common at all and even less commonly do people want them insulated after they are built. Saying that, I have insulated 2 of these in the last 30 years and so it is possible and sometimes it is not even that difficult if the internal construction is built in the right way. One of these that I insulated I removed the ridge cap and was able to pump insulation down from the very top to the bottom in each bay of the roof.
It is basically just a raked roof but very very steep. We do use special harnesses and even a cherry picker to get onto the roof when we have a difficult one like this to insulate.
Things that Matter to the insulation quote
If your professional is not taking notice of these things when insulating your home, he just might be putting your families lives in danger. Make sure that all these things are properly taken care of when you get insulation put in your home.
Any lights like the one on the right that go up into the ceiling are considered to be "Downlights" because they interfere with the roof insulation and need to have special precautions taken. Most of the time now days these lights are LED and do not have transformers that heat up but the NCC still requires them to be protected from all insulation. All insulation is required to be kept at least 50mm away from any heat source like a transformer or light. TV booster transformers and WIFI transformers are another one that need special care now too even though they are not explicitly mentioned in the NCC I would still treat them the same as any other heat source and leave a gap for ventilation.
If you have one of these lights in your home
A manhole should be insulated with a quality polyester batt and have a shroud around the outside of it when in the roof to stop any loose fill insulation being knocked down during access.
The steel flue on top of a fire place like the one on the right or even a brick chimney must not have any insulation in contact with it. The NCC requires a 300mm gap be left around any chimney or heater flue.
This includes batts and the pump in cellulose fibre product, it needs to have a good size gap around it to prevent any risk of fire in your home caused by the insulation installation.
Exhaust Fans and static vents
An exhaust vent like the one on the right is normally located in the bathroom or kitchen of your home. This style of motorised vent needs to be protected from being covered by insulation when insulating your home. It is easy to leave a gap around these and we recommend that you have vents turned on during the installation process to stop any dust being knocked into the home.
Static vents are a bit useless and if you have a quality insulation like cellulose fibre put into your ceiling, we normally recommend that static vents be blocked off with a bit of polyester batt rather than leaving them open. That is because static vents are more likely to allow back pressure heat into your home than to actually vent heat after installing a good insulation.
Access for the installation truck
When we measure your home with our online tools, one of the things we look for is good access for your truck. Overhanging trees in the driveway or a driveway that is to steep may mean that we have to leave the truck on the street. This will slow the job down considerably and it often means that we have to bring extra hose lengths it we are installing the pump in cellulose insulation. Our hose is about 30 meters long and this is enough for most houses but we do need to measure that while doing the quote
A bay window is a windowed area of the home that sticks out from the home allowing a greater view point. The one on the left is a typical design although the roof may be made from tile or iron. These bay windows often have access from the main roof cavity but when they do not, the roof above them will need to be lifted to gain access to insulate their ceilings.
A more common and similar design in Australia is a Built in Eave, that is when the builder extends the wall of a room out by the width of the eave for some extra space. These areas are not normally accessible from the main roof cavity for insulating but with the pump in insulation we can normally pump over into the eave from the main roof (as long as we know that their is no downlights or exhaust fans in them, this needs to be eyeballed from inside).
This is not one of our jobs but occasionally we have to rent a 3 story ladder to get onto the top of unit blocks to insulate them.
Roof Height and Fall Barriers
If we need to lift your roof to gain access to insulate it like in the case of a raked or exposed beam roof, then we always need to consider fall barriers and roof heights. On a standard single story home it is not a problem but once the potential fall height increases to a two story roof the risk of falling is substantially greater. If we are lifting a roof that is two stories high we must have a fall barrier on every side of the roof that we are working on or we will need to include the cost of installing roof hand rails around that area during the job.
Now that can get expensive and so most of the time it is easier and cheaper safer to use the manhole for access to install roof insulation when there is no fall barrier. Of course we have no choice in the case of a raked or exposed beam roof.
A typical fall barrier might be a veranda that can access the roof with a step ladder or even a veranda roof that is flat and means we do not need to be working within 1.5 meters of the edge of the roof.