We are looking to replace our existing terracotta tiles with new concrete tiles. As per title what should be be considering when we are looking for contractors to do the works? Any additional works that I should be considering getting them to do at the same time?
We have a two storey house with 30 degree pitch so access to roof is near on impossible most of the time.
Thanks in advance.
What is actually wrong with your roof that needs a whole new roof? Usually you just replace tiles, given it is terracotta might be just a clear coat.
If your actually supporting battens and beams are knackered then you can consider something like colorbond because even though people moan about it you won't get leaks if done properly unless a large object goes through it.
Terracotta tiles are ~80 years old and have definitely seen better days (starting to spall on back of the tiles - lots of tile broken). Have also considered colourbond, but design life is considerably less than tiles in near coastal location.
Have also considered colourbond, but design life is considerably less than tiles in near coastal location.
You are definitely right about that.
Definitely avoid Colourbond, even the top-shelf Ultra and SupaDura options are warrantied for less than 20 years when installed next to the coast.
I'd avoid concrete tiles too, the salty air will cause premature fading and you'll be constantly fighting against efflorescence from the dissolved salts, and their tendency to absorb water will leave you trying to power-wash lichen off every few months
Terracotta or Ceramic tiles will be your best bet, everything else will corrode or deteriorate within 20 years.
We've been using Terracotta tiles for over 2000 years now. Obviously how they're made is entirely different these days, but it's funny how some things just can't really be improved upon
Insulate EVERYTHING. Use Aircell or similar sisalation under the tiles for an even better thermal barrier. The less air movement in your roof the better
How long does Aircell last? Have heard that the standard sisalation they use only lasts 10 - 15 years or so(?)
Not sure why any sisalation would 'wear out' unless there's roof damage or the like…
Aircell, being a thermally-rated foil backed bubblewrap should last at least as long as any other product - likely well more since it's thicker and would have more strength.
To add to this, there are two main factors that you need to look into here.
The first is sarking, which is mandatory in Victoria and a few other states. This is a protective waterproof layer applied underneath the tiles, which gives extra protection against weather damage. This is incredibly important to get right, as it can't be easily reinstalled without redoing the roof.
Good sarking will provide extra insulation and reduce condensation inside a house. Bad sarking will let moisture build up in the roof space, causing mold growth and damage to roof insulation. You can easily get an extra 20 years out of a roof by using the right stuff.
It's absolutely worth spending extra here, and given you live near the coast, I'd look at using something with great vapor permeability like Bradford Enviroseal. You should explicitly ask the installer what they plan to use, because most will cheap out here to maximize profits as it isn't a headline item.
The second is roof insulation, which is mandatory nationwide. The R value of insulation is essentially a linear measure of how well it thermally and acoustically insulates, with diminishing returns for higher values.
The legislative minimum R value depending on the climate, flight paths, roof type, roof colour, sarking and other insulation. This is never below R2, but most areas require R4.1 for roof tiles with sarking.
R4.1 is usually fine in areas that don't experience much wind and aren't under a flight path. But personally, I would go for the new Bradford R7 Gold Batts, because the price premium over good quality R5 or R6 is tiny, and will pay for itself several times over.
I only recommend Bradford products because they've thrown a ton of time and money into their R&D over the last decade, and it really shows. Their high performance gold batts are the only ones that can provide R7 insulation with a single layer, and are the only ones with Asthma and Allergy certifications
Excellent, thanks for that.
Check if the quote includes scaffolding as some shonky contractors exclude this completely. There are arguments as to if you would be liable if they were to be injured onsite without taking precautions. Often this is a separate line in the quote so ensure its included.
Ensure the quote lists the number of replacement tiles, the brand and tile type. This will ensure that if they thought it was only 900 tiles and its more or less then you are aware of the variance. It also helps you in the future should you have breakages or replacing large amounts you know what to source. Ensure you have plenty of spares after they have replaced them.
Does the quote include removal of the rubbish (skip), clean up (as they will no doubt be dropping lots of rubbish around the house) and temporary covering while tiles are off?
Cement tiles breakdown over time (20-30 year lifespan) and can become brittle. If replacing terracotta with cement something to consider if your going to stay there long term.
The colour of the tiles/paint plays a large part in thermal dynamics in your home. Consider a darker roof will get hotter as absorbs more sun than a lighter roof (dark roofs look better). If you have ventilation like whirly birds or eave vents less of a problem. Also is your bathroom exhaust or rangehood (yes some places have rangehoods venting into ceiling space) venting to the roof space as this will need to be considered for the following point?
Also consider as all the tiles are off doing some preventative maintenance in replacing batterns , and upgrading insulation. You can upgrade your ceiling bats but if you have cement tiles you may want to consider Sarking (give it a google). Sarking and insulation needs to be considered holistically with venting and if your roof space is sealed.
There are lots of cowboy operators out there so be sure to get a few quotes, opinions etc. be sure not to go with anyone door knocking as there are plenty of horror stories (although im sure there are some exceptions to this of course).
hope this helps.
Excellent thanks for the detailed response. Much appreciated.
Consider Colorbond. Not suggesting it's better than concrete but many people swear by it. At least compare the pros/cons for your circumstances.
Have also considered colourbond, but design life is considerably less than tiles in near coastal location.
There are a lot of shonks in that business so be careful with who you choose.
During the re roofing they may drop tiles through onto your ceiling so take pics of your ceilings before they start and inspect it closely before you pay them.
Considered colorbond roofing?