How to Choose the Right Contractor for Waterproofing and Strengthening

• Ahmet Toka
• 7 August 2026
• Tips and Guides
• 4 min read

In waterproofing and strengthening work, the outcome depends on the quality of the workmanship far more than on the material used. The same product can give results ranging from twenty years to two years in the hands of two different teams. For this reason the real decision in this work is not a product decision but a decision about the firm.

In this article we explain what to look at when obtaining quotations, how to genuinely compare three different offers, the clauses that should be in the contract and the warning signs. Our aim is to place your decision on solid ground beyond price.

If there is a large gap between three quotations for the same job, the problem is not in the price but in the scope. Find out what the cheap quotation does not include; the answer is usually there.

Ahmet Toka, General Manager

Before the Survey: Know What You Want

A good quotation process begins with a well-defined need. Gathering the following information before calling firms in both speeds up your process and makes the quotations comparable.

• History of the problem: When did it start, under what conditions does it get worse, what has been done before?
• Photographic record: Photographs taken at different times show how the problem has progressed.
• Existing documents: Drawings if available, warranty documents from previous work, material information.
• Area dimensions: Approximate square metres, number of floors, access conditions.
• Constraints on use: Is the building in use, at what hours can work be done, is there a noise limit?
• Expectations: Are you looking for a temporary fix or a long-lasting renewal?

When this information is shared, the quotations that come in describe the same job and comparison becomes meaningful.

What to Look For During the Survey

The survey is also the first opportunity you have to assess the firm. In a good survey the following happen:

1. They ask questions. They ask when the problem started, how it relates to rainfall, and what has been done before. A firm that quotes without asking is working on guesswork.
2. They take measurements. Moisture measurement, area measurement and, where necessary, a surface check are carried out. Just looking and moving on is not enough.
3. They discuss the cause. They offer an explanation of the cause of the problem; they tell you not only what they will apply but why they will apply it.
4. They state the limits. They also say what the proposed solution will not solve. A quotation that says it will solve everything is not realistic.
5. They define what is out of scope. What work is not included and in what circumstances additional cost may arise are discussed.

For our approach you can request a survey from our contact page.

Genuinely Comparing the Quotations

Three quotations have arrived and the prices differ. To make the comparison meaningful, each quotation needs to state the following headings explicitly:

• Surface preparation: By what method will it be done? Blasting, grinding or just sweeping? This is the most common source of a price difference.
• Product name and brand: "Epoxy will be applied" is not enough; which product, how many coats, at what thickness?
• Consumption: How many kilograms/litres of material per square metre? That figure is the only objective indicator of thickness.
• Details: Are drain connections, corner coves, expansion joints and pipe penetrations included in the price?
• Testing and inspection: Will a water test, adhesion test or pull-out test be carried out; will the records be handed over?
• Removal and haulage: Is removing the old layer and hauling away the debris included?
• Programme: In how many days will the work be finished, and how long will each area stay closed?
• Warranty: How many years, what does it cover, in what circumstances is it void?

Once these items are clear, it often emerges that the quotation that looked cheap contains less work.

Verifying References and Documents

Obtaining a reference list is easy; verifying it gives you real information.

• Ask for similar work. Jobs of a similar scale and in similar conditions to yours are meaningful. A reference in a different line of business does not demonstrate competence.
• Ask about older work. Ask for a reference from a few years ago, not from this year. The quality of a waterproofing job only becomes clear after a few winters have passed.
• Call them. Ask the reference: was the work finished on time, did they come back when a problem arose, did they act under the warranty?
• Ask for documents. Company registration, tax certificate, applicator certificates if any, and insurance policy.
• Product documents. The technical data sheet and declaration of performance of the material to be used should be requested; certification is essential in particular for potable water and food contact applications.
• See a site. If possible, visit one of their jobs in progress. The order of the site gives the most honest information about the team's working discipline.

What the Contract Should Contain, and the Warning Signs

The contract should state in writing: the scope and limits of the work, the names of the products to be used, the application thickness and consumption, the tests to be carried out, the programme and works schedule, the payment plan (the advance proportion should be reasonable), the warranty period and its scope, and how a change of scope will be handled.

Warning signs:

• A firm that gives a firm price over the telephone without a survey.
• A quotation far cheaper than the others where the reason for this cannot be explained.
• A quotation that gives no product name or thickness and settles for the phrase "quality materials will be used".
• A firm that does not want a written contract and proposes only a verbal agreement.
• A demand for a high proportion of payment in advance.
• A firm that gives the warranty verbally and does not define its scope in writing.
• An approach that says "this method solves every problem" and defines no limits.

You can find the scope of our services on our services page, and our approach to waterproofing and strengthening on our waterproofing and structural strengthening pages.