The Craft of Re-roofing Heritage Homes

Restoring history

There are many challenges to re-roofing heritage homes. RANZ Member team Ascent Roofing is a specialist in this field.

There are three key considerations when approaching the re-roofing of a heritage home:

1. The roof’s structure, its historical aesthetics and, crucially, having the technical knowledge to complete the project. From a structural point of view, homes from a hundred years ago are built very differently from today’s homes. Materials, techniques, and even the environment have changed over the course of many years.

2. Aesthetics is another key point to consider when working on heritage homes. Any work carried out on a house with a long history needs to preserve and respect the original design qualities of the property. There is then the challenge to match materials that closely resemble the original with modern counterparts.

3. Last but not least is having the right team to tackle the job. These old roofs require delicate work to reserve their look and their spirit. This is perhaps the key consideration, as having seasoned roofers who are well trained in different roofing techniques can spell the difference between a proper re-roof and disaster.


Techniques unique to re-roofing heritage homes

Jeff Santos is a linchpin at Ascent Roofing, managing its team of experienced roofers and overseeing all of its training programmes. He says the roof is often the most overlooked part of these historic properties. “Normally, homeowners only bring a roofer on board when, a) they are fully renovating or building a new extension, or b) they finally experience a leak or an issue that has been out of mind but has now caught up with them.”

“In most cases, we would always recommend a roof replacement as the best solution, especially if the property is considered a heritage home or villa,” he says. “Around 85 per cent of our works are in roof replacement; of which more than half have been completed on heritage-style villas and homes across Auckland.”

He says one of the key things he would first make clients understand is that their roof forms one of the main architectural features of their house, and it is their roof that gives their home its shape and profile. “We also consider the suburb and the general feel of the neighbourhood when offering roofing profile options to clients. If someone, for example, were daring to go for E-span profiles on a heritage-looking villa, we would gently guide them to consider corrugated profiles instead, or even asphalt shingles as an option.”

When it comes to re-roofing heritage homes, there is no silver bullet approach. Careful attention to detail when removing and installing new sheets and flashings and taking care with any penetrations on the roof as needed.

“Most heritage villas also have asymmetrical roof shapes and structures, so it is imperative that experienced roofers work on these kinds of properties and have a good grasp and understanding of technical, structural requirements and how they fit within the current building standards,” says Jeff. “It is also worth noting that we will probably need to have discussions with and bring on board a builder, as around 70 per cent of the old villas we work on require specialist structural work that is within a builder’s scope.”

Ascent Roofing’s roofers are skilled in basic woodwork that come in handy, especially when there is a need to correct the pitch of a roof, correct valley structures or general batten replacements.

Specialist products and materials

As far as materials go, the exact materials used when these houses were initially built are no longer in production. Fortunately, modern alternatives are available and often benefit heritage homes greatly, says Jeff. “The quality and practicality offered by contemporary materials are far superior to the original, which will assure and preserve these homes for many decades to come.”

“Attention must be paid, however, to certain design characteristics – for example, curved veranda sheets, which need to be carefully measured and curled to match and respect the original design aesthetics. In some cases, the sheets that roll off from production may not be close to the exact measurements of the original, so care must then be taken by the team to customise the sheets by hand if needed to achieve the desired fit.”

Ardmore Road, Ponsonby

This property is estimated to be around 100 years old. When the homeowners called in Jeff to replace the original roof, it was already experiencing issues due to age and general wear and tear. The owners had specific instructions on what they wanted to preserve in the look of the building as it is indeed considered a heritage home. Initially, they asked to replace the roof using the same Mist Green colour, but Jeff suggested going with another lighter colour to refresh the villa’s look and make it look seamless with the rest of the building’s design. They settled with Colorsteel Titania 0.55 BMT, in corrugated profile. Curved sheets were used to replace the existing veranda roof, and the spouting was replaced with Marley Stormcloud.

Jeff’s team then stripped all the old sheets, installed self-supporting paper, and then laid the new sheets with 50mm screw fixings and installed all flashings needed to ensure water tightness. The team also installed new timber to support the new valley. The result was transforming a 100-year old villa keeping up with its elegant heritage.


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