A roofer stands with both feet on the exposed roof lathing while working on the roof.
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Renovating

Roof renovation: how to protect, maintain and insulate your roof

Arne Schätzle

Repairs, energy efficiency or an extension: there can be many different reasons for renovating a roof. When is roof renovation necessary, and when is it advisable at the very least?

Roof renovation – what you need to know

The roof is one of the most durable elements of a house. Most roofing materials last around 50 to 60 years. However, this doesn’t mean that you don’t have to worry about the roof for years. Even with new buildings, regular inspection is mandatory to keep the roof in perfect condition. Or to detect and eliminate construction defects at an early stage. However, replacing the whole roof is more often necessary on old buildings. The most widespread type of roof in our part of the world is the pitched roof, which can be either a gable roof or a single-pitch roof.

When does a roof need to be renovated?

Immediate roof renovation is necessary if the roofing is no longer waterproof and the rain comes through. This means that individual roof tiles have come loose, allowing moisture to enter the roof space in certain places. If this is the case, you should take action as soon as possible. If the damage to the roof is still minor, it can probably be repaired.

However, if moisture has permanently penetrated the roof, renovation becomes unavoidable. Otherwise there is a risk of moisture affecting the roof insulation or causing rotten beams, mold or fungal infestation. One example is roof fungus which spreads in damp masonry and damp wood. In the worst-case scenario, you may not only have to renovate your roof, but also replace the entire roof structure. Moisture, mold infestation, rotten wooden structures, cracks in the supporting beams, defective or loose tiles, all these are signs that should prompt an urgent renovation of the roof.

View over the roofs of a row of houses in Bern.

Roofers often use clay or concrete tiles to seal the roof. This roof covering is often also called roof cladding.

What are the options for renovating a roof?

The roof structure of a pitched roof consists of several layers: for waterproofing, i.e. the outer layer, roofers often use clay or concrete tiles. This roof covering is often also called roof cladding. Below this is the roof lathing on which the tiles are hung. Then comes the insulation, which is mounted on the roof structure, the substructure of the roof. Basically a distinction can be made between:

  • partial replacement, i.e. repairing individual parts. This is necessary in the case of selective damage.
  • complete renovation, where the entire roof structure is replaced.

Good reasons: energy-related roof renovations and attic conversions

Alongside moisture damage, insufficient thermal insulation or a complete lack of insulation are common reasons for getting a new roof, as poorly insulated houses consume excessive amounts of energy unnecessarily. Energy-related renovation, including thermal insulation, can help you save money.

Anyone who wants to exploit the expansion potential of their attic cannot usually avoid renovating the roof. This is because the roofs of older houses usually no longer meet today’s requirements for thermal insulation and airtightness. An extension will automatically involve converting the roof, for instance to install larger dormer windows or skylights – a structure in the sloping roof of a building is generally also fitted with windows. Although this type of project is much more comprehensive and expensive than a simple renovation, you will also benefit from the newly gained living space.

If you as a homeowner want to have a solar or photovoltaic system installed on the roof, you should also check the condition of the roof. Once this type of system has been installed, the roof covering will no longer be easily accessible – repairs will then be more complex and expensive. It is therefore advisable to check the roof beforehand and to undertake renovation or repair work if necessary.

View into the comfortably furnished attic of a single-family house following an extension.

Complete expansion of the roof is much more expensive than a simple renovation. At the same time, you will also benefit from the newly gained living space.

Can I renovate the roof from both the inside and the outside?

A roof can be repaired both from the inside and the outside. If the roof truss is not inhabited and therefore not clad, you can also have the roof renovated from the inside. A big advantage is that you are not dependent on the weather. However, if the roof truss is inhabited, the roof will usually be renovated from the outside.

Do I need to hire planners and architects to renovate my roof?

Whether you need a planner or an architect for your project will depend mainly on whether the work is minor, subject to notification or requires approval. New roofing falls into the category of minor work and is therefore feasible without additional planners.

Do I need a building permit to renovate my roof?

It is impossible to establish a general rule that applies to all cantons. Whether or not a building permit is required for your project depends on the location. A building permit is usually mandatory if a structural change is made (for example to install dormer windows, skylights or new roof trusses). However, there are some exceptions. Special care is needed in the case of protected historical buildings in particular. To make sure there is no danger of your project breaking the law, we recommend that you contact the local building authorities before you start renovating the roof.

How long does it take to renovate a roof?

This depends on the scope of the project. The choice of timing also plays a crucial role in the success of the renovation. Basically, spring is the best time to renovate or completely replace a roof. The mild temperatures make the work easier and you can expect fewer delays due to bad weather conditions. Early summer is also a good time to replace a roof. The temperatures are mostly mild. And you can assume that there is no risk of continuous rainfall hindering the work.

How much does it cost to renovate a roof?

The cost of renovation depends on several factors. Here we list the three most important ones – followed by an average price:

A craftsman applies a layer of insulation to a roof.

For above-rafter insulation, the roof needs to be removed and re-covered.

Scope

In principle, the scope of the renovation will have the greatest impact on the costs: do you simply want to replace the roof cladding or carry out a thermal renovation?
Do roof beams and rafters need to be replaced? Are new roof tiles necessary? Would it make sense to fit additional roof insulation? Does the old insulation still contain asbestos? The answers to these questions will have a direct impact on the cost of the roof extension.

Roof structure

In addition, the roof structure including the shape, pitch, skylights and windows has a huge effect on the costs. Depending on the shape of the roof, a distinction is made between different types of renovation: flat roof renovation, pitched roof renovation or tiled roof renovation. The costs also depend on the type of roof renovation.

Material

An additional factor that affects the cost of a new roof is the choice of material. There are many different possibilities, from roofing tiles or concrete tiles to metal profiles or bitumen shingles – roofing tiles made of roofing felt instead of concrete, clay or slate – or even fiber cement panels or thatched roofs.

Based on its database, “ofri”, the referral portal for tradesmen’s services, has calculated the cost of renovating a roof (including the following steps: re-covering the roof, replacing the roof truss and insulating the roof), the price was calculated at between 258 and 661 francs per square meter. According to ofri, completely renovating a roof costs an average of 10,800 francs.

What financing options and subsidies are available?

If you are considering renovating a roof for energy-efficiency reasons, or are planning to switch to renewable energy sources, you usually have a good chance of qualifying for subsidies. You can often hope to obtain tax breaks, low-interest loans or investment grants. However, funding levels and criteria vary from canton to canton. You can find information on financing possibilities and subsidies here:

Conclusion: it’s worth renovating your roof

Whether to improve energy efficiency, expand your living space or make use of renewable energies – the facets and advantages of renovating a roof are manifold. Not to mention the fact that it will increase the value of your property. Under some circumstances you may even be entitled to a subsidy to help finance your project. Good luck with your roof renovation!

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