Above: The finished cape cod roof replacement at happy valley.
At Oz-Roof we do many roof replacements every year and really enjoy the challenges presented by each individual job. Houses are a bit like people in that no two are exactly the same and this is evident with every house roof.
We recently had the pleasure and challenge of undertaking a full roof replacement on an interesting Cape Cod style 1990s house in the Adelaide suburb of Happy Valley. The owners had lived in the house for many years but were never happy with the performance of their roof. Having spent years putting up with roof leaks, excessive wind noise and a lack of Insulation they decided to engage Oz-Roof for their full roof replacement and roof conversion to Insulated Colourbond roofing.
Above: Part way through the roof replacement. New Colourbond installed on the right, middle blue area stripped and battened, original metal roof tiles still in place on the left.
Table of Contents
Metal roof tile replacement
The original roof design was quite interesting in that it was clad with decramastic metal roof tiles installed with the original build, back in the early 1990s. Most houses with decramastic metal roof tiles were originally built in the 1920s and 1930s and had original corrugated iron roofs. Fast forward 50 – 60 years in the 1970s and 1980s and these houses were due for a re-roof. Popular for a short period of time was to leave the original corrugated iron roof in place and clad over the top with decramastic metal roof tiles. Unfortunately, this form of roof cladding was highly problematic, the biggest problem of all being fragility. Its almost impossible to walk over this type of roofing without denting and caving in the tiles. Once dented they become very easily blown off the roof by wind and cause roof leaks.
Above: Sliding image of the before and after at the cape cod pitch change. This is the point at which the roof sheet and the wall sheet meet. Note the transition flashing and zero sheet overhang.
Roof replacement process
Given the difficult access caused by the Cape Cod design and considering safety is of utmost importance during the roof replacement process we had full perimeter scaffolding with multi levels installed to the property prior to starting our work. The roof had a small solar array which our Solar electrician removed and stacked in the client’s garage for the duration of the job.
Above: Strips of metal roof tiles being removed from the roof surface.
The only good point of Decramastic metal roof tiles is the speed at which they can be removed from the roof surface and disposed of. This particular metal tile type was great for this in that each sheet of cladding is actually four tiles wide. They are also very light and can be recycled due to being all metal.
After removing all the metal roof tiles in a given area the next stage is to install the metal roof battens. We install these at frequent 900mm centres to give the new roof a good strong substrate for fixing to. The original timber tile battens are left in place and really serve no purpose other than keeping the roof Insulation blanket held in close contact with the underside of the new roof sheet.
Above: A roof section removed, and new metal roof battens installed at 900mm centres. Ready for Insulation blanket and new roof sheeting.
When all metal battens have been installed the guys then roll out foil backed Insulation blanket over the top of the metal battens and old timber tile battens. Finally, the new roof sheeting is installed over the Insulation blanket and fixed. We used the True Oak deep 21mm roof sheeting for this project. The look of the deeper roof sheeting is great, and it resists denting far more then the regular 16mm corrugated sheeting found on most houses.
Above: 50mm foil backed Insulation blanket rolled out over the battens with roof sheeting going down over the top.
We designed a new transition flashing for the pitch change point in the Cape Cod roof. The flashing caps over the top of the wall sheet by 80mm and actually flashes under the edge of the roof sheet by 250mm. The deep back flashing just ensures that no wind driven rain will ever find its way back into the roof space and cause any leaks. To give the roof a tidy look we decided not to overhang the roof sheet but rather to keep it level with the fold line in the transition flashing.
Above: The finished rooftop with a solar array partially re-installed before the scaffolding comes down.
Solar Panels with Roof replacement
Before ordering for the scaffold to be removed our solar electrician re-installed the original solar array to the rooftop. In this case they actually discovered that several of the original solar panels had dead cells and the owner decided to replace them while the scaffold was erected.
The finished roof replacement looked fantastic. The owners were really happy with the result. The whole home is now far more Insulated against heat and cold. The leak issues and wind noise are completely resolved.
Check out the fantastic review we received from the homeowner on our Google reviews
