How to assess a roofer before awarding the contract

A good contractor asks about the design, the condition of the structure and the planned covering. He wants to know the number of chimneys, windows and roof penetrations. In the case of renovation, he is also interested in the attic and traces of previous leaks. He does not have to know the final price straight away, but he should be able to explain what data are needed for a reliable quote.

It is worth checking whether the conversation covers the entire layer build-up. The choice of colour alone does not determine ventilation, insulation and flashings. The specialist should identify the points requiring agreement with the designer. A willingness to explain limitations is a good sign. A promise that every problem can be dealt with on site without documentation should raise caution.

Modular tile-effect metal roofing, cut sheets and trapezoidal sheet differ in their details. Within one group there are also various interlocking seams, batten spacings and fixing methods. Experience is valuable, but it does not excuse anyone from reading the current instructions. A good roofer can combine practice with the requirements of the precisely selected material.

It is worth asking how the eaves and ridge will be resolved and where the water from the underlay will be drained. The answer does not have to be a lecture. It should, however, show that the contractor understands the function of the detail. A random sealing compound does not replace a correct connection. The specialist distinguishes a system solution from a makeshift attempt to mask a gap.

Look for roofs similar in terms of covering and complexity. Straight sheet lines are important, but it is also worth examining the flashings and drainage. If possible, ask the owner about the course of the works and how defects were rectified. A new roof on a sunny day does not yet show how it behaves during heavy rain.

Photos of concealed layers say more than the final result alone. They allow the care taken with the substructure, the membrane and difficult connections to be assessed. A contractor should not disclose clients’ private data in order to demonstrate his workmanship. Factual technical documentation and projects shared with the owners’ consent are sufficient.

Materials are unloaded and stored so as not to damage the coating. The team has the right tools and a plan for passing the sheets up. Coated steel sheet is cut using a method in accordance with the instructions. Swarf is removed before it remains on the surface for any length of time. Tidiness on the roof slope is of technical, not merely aesthetic, importance.

Safeguards and reaction to weather matter. A large sheet can be difficult to control in wind. A wet roof slope increases the risk of slipping. A reliable contractor can stop work and secure the building. They do not treat dangerous haste as proof of experience or as an argument for a shorter deadline.

The contract or order should specify the scope of materials, works and responsibility for deliveries. It is worth separating the substructure, layers, covering, flashings and gutters. The method of settling repairs revealed after dismantling must be established. A good contractor can describe these boundaries instead of leaving all additional costs to a conversation after completion of the works.

Acceptance is also important. It should be clear when the layers can be inspected before covering and how comments are to be reported. Clear arrangements help both parties. They do not indicate a lack of trust. They help avoid a situation in which the client expects a complete roof while the crew believes it was only instructed to screw down the sheets.

A defect can also appear in a well-organised project. What matters is whether the contractor diagnoses it, documents it and proposes a specific repair. The place of the leak does not always indicate the source of the water. Therefore a reliable reaction includes checking the detail, not just sealing the nearest gap with sealant.

After completion of the works, the roofer should provide information about the materials and maintenance rules. It is worth keeping photos and markings of the covering. Good craftsmanship is also recognisable by such an orderly completion. The client then receives the roof and the knowledge needed to maintain it. This is more useful than a mere assurance that everything was done as well as possible.

Do not judge a crew solely by the lowest rate or the number of years in business. Check that its experience matches your own task. A small canopy, a complex house roof and a hall with sandwich panels require partly different skills.