Comparing labour quotations for a sheet metal roof

One quote may cover only the installation of sheets on a prepared substrate. Another also includes the membrane, counter-battens, battens, flashings and gutters. Both may use a similar abbreviation in the heading. Therefore, the activities must be itemised before comparing the price. Also establish who measures the roof, prepares the material schedule and is responsible for any shortages.

In a renovation, dismantling, waste sorting and protection of the interior are listed separately. Replacing damaged substrate elements may require an additional quote once they are exposed. This does not automatically mean unreliability if the rules were agreed in advance. The problem arises when it only becomes apparent during the works that the parties understood the scope differently.

A simple gable roof and a roof with numerous dormers may have the same square metreage but completely different labour intensity. Every valley, corner and penetration requires fitting and flashings. A large number of short slopes increases the amount of cutting. The height of the building and the possibility of setting up scaffolding also affect the organisation and duration of the work.

The quote should therefore be based on the design or a measurement. It is useful to state the lengths of the edges and the number of details. Part of the scope can be billed per metre of roof slope and part separately. More important than the unit itself is a clear definition of what will be done for the agreed amount and how the quantities for the final settlement are calculated.

Long sheets cut to size cover a large area but require safe lifting and handling. Modules are handy but require a greater number of repetitive operations. Trapezoidal steel sheet has different rules for support and fixing. None of these features provides a universal labour rate without taking the specific roof into account.

Sandwich panels can quickly close a large area but often require lifting equipment and careful inspection of the supports. The cost of operating a crane or vacuum lifter should be visible in the quote. Installing a panel also involves sealing the joint, making flashings and penetrations. Omitting these works distorts the comparison with a traditional layer build-up.

Ask about scaffolding, safety measures, material delivery, unloading and cleaning. Establish responsibility for waste and damage to the coating. Check whether the price includes documentation of concealed layers and partial handovers. These activities are of practical importance, especially when several crews are responsible for different parts of the same building envelope.

Describe the method for approving additional works in the contract. For renovation, you can specify rates or the procedure for preparing a separate cost estimate after exposure. Do not leave consent for arbitrary works without price information. On the other hand, do not require the contractor to guess in advance the condition of the hidden structure. A clear method of procedure is needed.

A low price may result from efficient organisation, a simple scope, or omission of significant items. First ask about the difference. Check fixings, flashings and protections, instead of immediately considering the offer favourable. Similarly, a high amount alone does not confirm quality. The contractor should be able to explain the scope and requirements that affect the cost.

Compare completed projects with similar material and the handover procedure. A good offer includes the deadline, scope, payment terms and responsibility for execution. It is worth knowing who will actually work on the site. The ability to execute a difficult detail is more important than the promise of the fastest deadline for any roof.

Prepare a description of works and a set of drawings common to all contractors. Ask for exclusions and net and gross amounts. Agree on the method of measurement, acceptance and rectification of defects. Link payments to specific stages. As a result, the labour price will mean a predictable result, not just an approximate number per square metre.

There is no single reliable rate valid for the whole country and every job. The best reference point is comparable offers for your roof. If they differ significantly, check the items before you start negotiating the total. Often the answer to where the discrepancy comes from lies in the scope of flashings, substrate preparation and equipment.