Roof renovations and their servicing

Roof renovation (repair) can pose a challenge for both the designer and the contractor. For example, the cost of replacing an old roof with a new one including the necessary protection elements for an operating retail centre may amount to 50 / 75 EURO/m2 x 10 000m2 = 500 000 / 750 000 EURO.

Optimizing the renovation plan can decrease this cost by 1/3 or even by half.

Bringing together theory and 25 years of practice, we fully understand the complexity of flat roofs. This perspective helps us optimize the costs relative to the durability of the new roofing.

For many companies in Poland, the period between 1995-2005 was a time of implementing new technologies, e.g. synthetic insulation (i.e. PVC) or 1- or 2-layer alestomeric-bituminous insulations. Taking into consideration similar learning processes in other European countries, 20%-30% of roofs made during that time presently require renovation.

During the design process, it is essential to carry out a proper analysis of: surface construction building wrap including thermal insulation, degree of dampening, anti-water insulation, internal and external climatic conditions.

Only a correct analysis that includes static, wind and thermal-dampness calculations allows proper dimensioning of:

- perforation level of an existing roofing,

- thickness and type of insulation,

- anti-water insulation in relation to its vapour-permeability,

- selection of mounting elements,

- strengthening of an existing construction in case it was needed.

It is of key importance to perform thermal-dampness calculations for a period of e.g. 10 years. Using the Glaser method and traditional calculating programs, it is impossible to accurately assess the accumulation of water.

Based on the following program, we design optimal layer layouts for flat roof renovations.