Is it better to repair or replace a roof?

There are roofs in Sydney that leak since the day it was built. These are ‘Lemon’ roofs and are mostly beyond the possibility of a repair and therefore a complete roof replacement is warranted.

Pair a lemon with a car and you get something unpleasant. As a roofer, lemon roofs are just as foul and I just see too many of these shocking roofs being installed for unsuspecting homeowners.

Most days, I shake my head when I climb on a roof in Sydney. The faults on the roof are so blatantly obvious that it makes my job of finding where the roof leak is coming from – so un-challenging.

Just as chefs should eat their own culinary creations, I think roofers should live under the roofs that they put up when Sydney gets those long bouts of stormy days. They can then have a go at trying to repair their own roof that they did not take the time and effort to do properly.

When I stuff up and I don’t know about it – I keep thinking that I am a genius. The times that I have had to take responsibility for my errors have been the greatest learning opportunities.
I just wish that all roofers are forced get to go back to fix the leaking roof that they have been responsible for…

Only then will they realise that the roof is beyond repair and it should be replaced by a better roof.

Some roofs are easy to repair and some are just too challenging – and demand a replacement instead.

It is hard to go wrong on a factory roof in the outer western suburbs of Sydney. Long straight sheets. Regular rectangular shapes. Easy crane access. Easy parking. Simple edge flashings.

Switch to an Inner west roof in the Erskineville and Newtown areas, and the degree of difficulty of installing a new roof ramps up. Add in skylights, flat skinny roofs, chimneys, parapets and parking inspectors…. And mistakes plus shortcuts. This is a recipe for disaster that points to roof leaks and premature roof lifespan.

And probably resulting in needing a roof replacement rather than just a roof repair.

For a better perspective on Inner west roofs, I have a special post on that subject.

We hardly get to repair many factory roofs. But we get to fix a lot of residential roof leaks in Sydney’s inner west. It is the small roofs that have the highest failure rates when it comes to roof leaks. And these are the roofs that require an expensive roof replacement rather that a repair

Be careful with flat metal roofs

“Keep away from corrugated roofs.”
This is my best advice for anyone contemplating the modern look of a low pitched roof. The corrugated roof profile is not designed to be laid ‘flat’. Flat corrugated roofs cannot be repaired effectively and often have to be replaced by a ‘kliplok’ or ‘trimdek’ profile roof

5 degrees is usually the manufacturer’s recommended minimum slope for corrugated roofs.  See what happens if you don’t follow this pitch recommendation on a separate post.
Personally, I think 8 degrees should be a better limit to set. I have seen way too many leaking corrugated roofs.
Then people like cutting large holes on flat roofs and installing skylights.
There are two things to think carefully about with these skylights.

  1. Choose the right skylight. Not all skylights can be installed on flat roofs.
  2. Design the flashings correctly. ALWAYS design and install a tray flashing .  See my leaking skylight page for tray flashing details.

Even small holes for vent pipes and exhausts can benefit from a tray flashing – especially if the hole is cut where two roof sheets lap together.

What is the best roof sheet profile for flat roofs? 
I still prefer the ‘Kliplok’ profile for all flat roofs. The higher and stiffer ribs combined with ‘no screws’ cuts down on a lot of potential leakage paths. It is much better that the cheaper ‘Trimdek’ profile roof.

Can ‘Lemon’ roofs be repaired at all?

I have a friend who is quite patriotic and he used to support the local Holdens. He bought a Calais (remember the premium Holden Commodore?).
After the sixth warranty repair in the first 6 months, he gave up on Holden. He sold the car and bought a Mazda. He keeps saying to this day that If Holden had just accepted the problems with the lemon car and gave him another one that worked – he would have stuck with the local manufacturer.

It is pretty much the same with a roof if there are some major design/installation problems. You can keep repairing the roof leaks but these tend to be short term fixes.
Usually it is better to just ‘bite the bullet’ and rip the offending roof off and replace it with a proper one. It does not matter if the roof is just 6 months old.

There will always be exceptions. A good roofer will be able to assess the merits of a roof repair vs a roof replacement and make you a recommendation.

The future for roofs in Sydney?

More apartments are going up than houses. A lot of home owners will have strata managers looking at any roof problems. Small building envelopes and height restrictions means that architects are designing low pitched roofs (and making it look good).

Both situations means that it will become more difficult to repair or replace problem roofs.
Prevention is always better than cure (unless you want to live through disasters to really experience the lessons that can only be learnt this way).

So, hopefully with the spread of better information, there will be less leaking ‘Lemon Roofs’ in Sydney.