Can sarking be installed on a roof that is already on?
Yes. It is the single most common question we get asked about this and the answer is straightforward: the tiles come off the affected area, the sarking goes in, the same tiles go back on. You are not buying a new roof. You are adding the layer your roof was built without.
Most Sydney tiled homes built before the 1990s have no sarking at all. That is not a defect and it was not a corner cut at the time, it was simply how roofs were built. The tiles were the entire waterproofing system.
Does your roof actually need it? Five signs
Sarking is not the answer to every leak. Here is how to tell whether it is the answer to yours.
Two or more sound like your house?
Then it is worth a look. The inspection is free, you get a photo report you keep either way, and if it turns out sarking is not your problem we will tell you that instead of selling you one.
What the job actually involves
On a tiled roof, working section by section:
- Tiles lifted off the affected area and stacked on the roof. Most go straight back on, only broken ones get replaced.
- Old battens removed and the section stripped back to structure.
- Any timber that has rotted from years of water gets dealt with while it is open. This is the part nobody can quote for until the roof is off.
- Heavy duty sarking laid across the section and carried down over the eave so it discharges into the gutter, not behind the fascia.
- New battens fixed over the sarking.
- Your tiles re-laid, ridge capping re-bedded and re-pointed where it has been disturbed.
An open section is always closed the same day. Nobody leaves a roof open overnight, and if the weather turns before the tiles are back on, it gets covered.
What roof sarking installation costs in Sydney
There are two shapes of job here, and most people who call assume they need the second one when they need the first.
Sarking the area that leaks: from $3,000. The failing section comes off, gets sarked, and goes back on. Everything else stays exactly where it is. Depending on how much area is involved these run up to around $10,000.
Whole roof, new battens and sarking: from $10,000. Every tile comes off. Every batten comes off. Sarking goes down, new battens go on, and every tile goes back. It is the same job as a re-roof without the cost of new tiles, which is why a large, steep or two storey roof can reach $18,000. That number is labour, not materials.
Yours is probably the cheaper one
Most people who ring us thinking they need the whole roof done only need the section that is actually failing. We cannot tell you which one you are from a website, and nor can anyone else quoting you over the phone. That is what the inspection is for. It is free, it takes about half an hour, and you keep the photo report whether you go ahead or not.
As a real example, the Lugarno job in the photos above came in at $4,000 to $6,000, and that covered stripping and re-sarking the failing under pitch section, re-laying the tiles, and a complete new gutter, fascia cover and barge flashing system at the same time.
Worth putting against the alternative. A full tile roof replacement on a typical Sydney house lands in the high twenties and up. If your tiles are still sound, re-battening and re-sarking gets you a roof that keeps water out for a fraction of that, using the tiles you already own. You can price the expensive end yourself with our roof replacement cost calculator, which measures your roof from satellite in about thirty seconds.
What moves the number: how much roof has to come off, whether the battens and timber underneath are sound, roof pitch and access, tile condition and how many need replacing, and whether the ridge capping needs re-bedding once it has been disturbed.
Every quote is fixed and in writing before anyone starts, and the inspection that produces it is free with a photo report you keep either way.
Sarking retrofit or a full roof replacement?
Honest answer: it depends on the tiles, not the sarking.
If your tiles are sound and the roof is simply missing its second line of defence, retrofitting sarking is by far the cheaper answer and it solves the problem properly. If the tiles themselves are at the end of their life, spalling, porous, cracking underfoot, then you are paying to lift and re-lay tiles that need replacing anyway, and a full re-roof is the better use of the money.
We tell people which one they are looking at, including when the answer is the cheaper one. If you want to see what the expensive end looks like before you decide, our roof replacement cost calculator measures your roof from satellite and prices a full replacement in about thirty seconds.
Does a Colorbond or metal roof need sarking?
Different problem, same product. On metal roofing, sarking earns its place mainly through condensation control rather than wind driven rain. Steel is cold at night, warm moist air rises out of the house, and it condenses on the underside of the sheets and drips onto your ceiling. People report that as a leak and it is not one, and no amount of looking for a hole will find it.
Sarking with a suitable vapour permeable membrane gives that moisture somewhere to go. If you are re-roofing in Colorbond it goes on as part of the job. See Colorbond roofing Sydney and metal roof repairs.
See a full job, start to finish
We photographed an entire leak and sarking repair in Lugarno, including the foil tape someone had stuck over the same leak before us and the rotted battens underneath it.
Common questions
Can sarking be installed on an existing roof?
Yes. The tiles over the affected area are lifted, the sarking and new battens go in, and the same tiles are re-laid. You do not need a new roof to get sarking.
How do you install sarking in an existing tiled roof?
Section by section. Tiles come off and are stacked on the roof, old battens are removed, the sarking is laid across the structure and carried down over the eave into the gutter, new battens are fixed over it, and the original tiles go back on.
Do you have to sark the whole roof?
No. Where the failure is confined to one section, usually an under pitch area, sarking that section is the cheaper and entirely legitimate fix. Whole roof sarking makes sense when the tiles are coming off anyway.
How much does roof sarking installation cost in Sydney?
It depends on how much roof has to come off. Sarking just the area that leaks starts around $3,000 and runs to about $10,000 depending on the area involved. A whole roof sark means every tile and every batten comes off and goes back on, which is the same job as a re-roof without the cost of new tiles, and that runs $10,000 to $18,000. Most people who call assuming they need the whole roof only need a section, so the onsite quote is worth having before you budget for the bigger number. Every quote is fixed and in writing before work starts.
How long does it take?
A single section is typically a day. A full roof depends on size, pitch and access. Whatever is opened is closed the same day.
Is sarking required for a Colorbond roof?
On metal roofing the case for sarking is condensation control rather than rain penetration. Warm moist air from the house condenses on the cold underside of the sheets and drips. A suitable membrane manages that, and it goes on as part of any re-roof we do.
Will my tiles survive being lifted and re-laid?
Mostly yes. Some breakage is normal and we replace what breaks. If a large share of your tiles are too brittle to handle, that is a sign the roof is closer to replacement than repair and we will tell you.
Related: roof leak repairs Sydney · tile roof repairs · Colorbond roofing · the full job walkthrough