Is it possible to renew the waterproof properties of an old bituminous membrane?
One of the most frequent uses of liquid waterproofing products is undoubtedly the recovery and renewal of old prefabricated bituminous membranes in rolls. Instead of removing and disposing of them, thanks to the help of multifunctional liquid waterproofing products, it is possible to renew their waterproofing properties, extending the life cycle of the pre-existing bituminous rolls.
Environmental protection and economic saving
The Environmental Unified Code defines (Legislative Decree No. 152/06 and subsequent amendments) Art. 184, c. 3 “special waste” all the products derived ” …from the activities of demolition and construction, as well as waste deriving from excavation activities… “.
Based on this, it is possible to make two distinct considerations involving purely economic aspects and, no less important, direct effects of environmental impact.
From an economic point of view, recovering and renewing a pre-existing waterproofing covering, avoiding its disposal, certainly ensures direct and tangible savings for the costs of removal and landfilling: in the cost estimate, the item regarding only disposal cost is a burden that , at national level, is evaluated with an average cost of about 0.65 €/kg. Considering that the average weight of a single layer of preformed bituminous membrane is 4 kg/m2, the disposal cost will be approximately €2.60/m2. Assuming that a state-of-the-art work has been carried out on the surface, we will have two sheath layers in place for a weight per m2 of no less than 8 kg, doubling the costs just described and bringing them to over €5/m2. It should not be forgotten that in addition to the cost of disposal, the labor costs necessary for the removal must be added as well as the costs for characterizing the waste itself and the transport cost to the treatment site.
From an environmental prospective, having the opportunity to “renew” the waterproofing properties of the old waterproof package, due to the use of liquid waterproofing agents, means no disposal and landfill, reducing the environmental impact of this process.
A choice for the environment and a safe re-waterproofing
Considering the adoption of a Liquid System for the recovery of the hydraulic seal of the surface is therefore a mandatory step and no longer an option. The Liquid Systems guarantee impermeability by creating a continuous layer of reduced thickness with characteristics that are completely assimilable and comparable to the classic hot-laid preformed systems.
The Condicio sine qua non is the assessment of the actual state of the support to be restored which must be under such conditions as to be able to “receive” the new coating, first of all guaranteeing excellent adhesion. It is important to establish the actual state of the application substrate and be aware that sometimes it is not always possible to intervene with these solutions: uprooted sheaths with the presence of dense vegetation, thinning of the old bituminous layer with the presence of the exposed reinforcement layer, critical points such as passing bodies and drains, flaps and the presence of photovoltaic systems may require disposal.
But in all other cases it is not only possible, but desirable to re-waterproof the old membranes in rolls with liquid waterproofing products.
Small tricks for a proper re-waterproofing
The high levels of humidity that are normally present under the old impermeable layers can be managed by using steam vents located every ≈15 m2.
These accessories, such as Icobit’s Exit Air, are very effective in order to create points of preferential outflow for the humidity underlying the surface, humidity which under the action of solar radiation will tend to flow outwards.
In addition, on a coating with left exposed roll membranes without mineral protection, degraded and with infiltrations, a preliminary check of the state of the support is standard practice, both to identify the “preventive” restoration operations to be performed and the type of intervention to be realized.
Lastly but not least, we recommend to check the state of any protective varnish (if present), visible welding, localized damage (cuts, holes, etc.), vertical flaps, the state of the sheath in proximity to eaves gutter, drains and contact joints with sheet metal work, etc.
Icoper line as a solution for re-waterpoofing
Among Icobit waterproofing products, the Icoper system is the solution with an optimal compromise between benefits and costs.
It is a one-component, coloured, multi-purpose continuous membrane in water emulsion, ideal for waterproofing attics, roofs, roofing in general, fiber cement sheets, metal supports, gutters. Certified for asbestos cement encapsulation, with the Icoper system it is possible to re-waterproof, without disposal, old bituminous membranes in rolls.
The typical re-waterproofing work cycle involves the application of an Icofiss solvent-based acrylic fixative, which has the function of reinvigorating the surface layer of the old bituminous membrane: its work is simple but effective because in the application phase, which takes place with a roller, the solvent contained in it dissolves the surface part of the bituminous membrane, depositing at the same time a special resin which forms the starting point for the application of the Icoper waterproofing agent.
The Icoper waterproof membrane will be “spread” after the Icofiss drying with simple and common aids, such as a roller, brush or airless.
The waterproofing package thus created is certified according to the harmonized standard
UNI EN 1504-2:2005 ““Products and systems for the protection and repair of concrete structures – Definitions, requirements, quality control and conformity assessment
Part 2: Concrete surface protection systems” according to the following principles:
- Principle 1 – Protection against ingress (PI)
- Principle 2 – Moisture control (MC)
- Principle 8 – Increase in resistivity (IR)
The versatility of the Icoper system therefore makes it possible to incorporate some reinforcement fabric within the liquid waterproofing layer with which you can improve the characteristics of mechanical resistance, addressing the use of this solution also on large-sized construction sites, where it is necessary to achieve better performance of dimensional stability of the entire waterproofing package. The stability of the colours, chosen by the customer, and the resistance to UV rays of the Icoper System avoids the use of additional protection products in cases where the waterproofing is left exposed. The waterproofing can be walked on for all maintenance interventions.
Check out the numerous versions of the Icoper line by the link https://www.icobit.com/it/la-gamma-icoper or send an email to info@icobititalia.com