FAQ For Kemper Liquid
What is cold-applied liquid waterproofing?
The two most familiar types of flat roof waterproofing are: "Hot Applied" The build up of one or more layers of molten bitumen and roofing felt to create an impervious membrane, sometimes involving the direct use of flamed torches to heat the bitumen to the required temperature.
This process gives off noxious bitumen fumes and has an associated fire risk through the use of boilers or torches on the building itself. Cold Applied this method avoids the use of heat or flames and instead uses specialist cold liquid resins to impregnate a fleece−based substrate which then cures to provide a waterproof membrane. Solvent−based systems are rapid−setting but may give off fumes whilst curing.
Kemper are the only cold−liquid manufacturer offering a solvent−free alternative, 2K−PUR, which make it particularly suitable for the repair of roofs on schools, hospitals and other occupied buildings.
Can Kemperol repair asbestos roofs?
Kemperol 1K−PUR with a coating of Coelan acrylic is the ideal solution for failed asbestos roofs. There's no need strengthen the roof, or to remove large areas of asbestos, which is simply cleaned and primed prior to sealing with Kemperol at the sheet joints and fixings, with the whole roof then encapsulated with Coelan to seal and protect.
The result is a low cost solution that minimises the risks and cost of specialist asbestos handling and disposal, has a very long life expectancy and refreshes the appearance of a tired asbestos roof.
Can Kemperol be used on pitched roofs?
There are a number of applications where Kemperol can be used to repair existing roofs or even for newbuild:
Lead roofs:
Kemperol is an ideal substitute for lead as a repair material on both falt and pitched roofs: it is far cheaper to install and will bond to the existing lead roof without the need for removal, can be walked on for maintenance traffic and is elastic – so withstands thermal movement. It can also be used for newbuild roofs using timber battens to simulate roll joints. Dark and Light grey colours are available for a new or weathered appearance.
Copper Roofs:
In the same way, Kemperol can be used to repair pitched copper roofs or for newbuild. It can be specified in a Green Patina finish that simulates weathered copper.
Asbestos:
Corrugated asbestos roofs can be repaired using Kemperol 1K−PUR with Coelan. Kemperol is used to seal the sheet joints and fixings, with a final application of Coelan acrylic coating over the entire roof to seal and encapsulate. This avoids the expense and health hazards of removing a failed asbestos roof. The mid Grey coloured Kemperol refreshes the appearance of a tired asbestos roof and resists algal and fungal growth.
Do I need to upgrade roof insulation?
When repairing roofs, not only can Kemperol often be applied without removing the existing material, if this is in generally sound condition, but in this instance the insulation does then not need to be upgraded to comply with current Building Regulations − as is the case when replacing the original roof material. This allows building owners the option to either replace or not dependant on local considerations.
Should you want to upgrade the thermal performance of an existing roof, our Stratex warm roof construction is a complete system comprising primers, vapour barrier, insulation and waterproofing with a range of optional surfacing treatments if required.
Does the old roof need stripping first?
This is not quite a straightforward question to answer, as many factors will affect the decision.
However, Kemperol is a hugely versatile waterproofing material with primers suited to different substrates wherever this might offer a superior bond to the standard primer . This means that in the majority of cases there is no reason for the substrate on a leaking roof to be removed − Kemperol forms an immensely strong bond and will create a waterproof membrane that is elastic (so will withstand movement) yet is also permeable to vapour, allowing the roof to breathe. Where existing roof materials are to be covered, it is important to ensure substrate is sound, free from loose material, clean and dry.
Even previous repairs and damaged substrates may be covered with confidence, for Kemperol will bridge cracks and tears up to 2mm, whilst anything larger can easily be made good on site using a mix of resin and kin−dried sand − your contractor would be able to advise on this, following an initial site visit.
And because Kemperol is a lightweight repair system, it is highly unlikely that the existing supporting structure will need to be strengthened in order to accommodate the additional loading of the Kemperol membrane.
What are the hidden benefits of Kemperol
Kemperol cold−liquid waterproofing will typically save time on site compared to other waterproofing systems, which ultimately should be reflected in lower actual costs. But aside from the installation costs, this speedier completion means less disruption (in the case of repair work), whilst with Kemperol solvent−free there will be many applications where costly disruption is avoided altogether, due to there being no need to evacuate the building or suspend production. This can represent a major cost benefit to manufacturing businesses, warehousing and food preparation, schools, hospitals, offices, hotels − indeed any working environment where disruption to operating processes will incur a real cost.
What are the benefits of 'Wet on Wet'
Compared to other cold− applied liquid waterproofing systems, Kemperol is the only leading brand that is applied 'wet on wet'. In practice this means the polyester reinforcing fleece is first saturated with Kemperol resin, bonding the membrane to the substrate, with the surface layer then applied onto the bonding coat whilst still wet, so forming a single seamless membrane of uniform thickness.
As a result, Kemperol has all the benefits of a cold−applied system, whilst offering three major advantages over all other cold−applied systems where the basecoat and top layer are separately applied:
− there is zero risk of delamination through poor bonding between the layers
− full absorption of resin into the fleece is easily visible − a foolproof way to ensure an adequate thickness of resin, avoiding the vulnerability of other systems to 'thinspots' when contractors do not use gauging equipment to confirm adequate base layer thickness as recommended.
− Considerable time saving: without the need for drying between coats it is feasible to completely waterproof large areas of roof in a single day.
What are the benefits of cold-applied?
Compared to hot−applied methods (torched bitumen) there are no fire risks or associated insurance, health & safety and operator restrictions. As Kemperol systems are all vapour permeable this allows the building to breathe whilst the solvent−free options enable work to proceed without the need for evacuation or production stoppages.
Kemperol will bond to a great many substrates, allowing its use in many situations without having to remove and dispose of the existing roof covering. This saves time and avoids the cost of removal and cost/environmental issues associated with disposal. In many cases the Kemperol roof system can be installed or repaired without the need for scaffolding a further cost saving that also minimises disruption on the site. Finally the superior robustness and durability of cold applied waterproofing compared to other systems makes life cycle costings particularly attractive for those who may have a vested interest in the long term performance of the roof system.
Why use cold-applied for repair
The major advantages of cold applied liquid roofing for flat roof repairs can be summarised as:
• Cost−effective
• Unlike torch−applied systems, no risk of fire
• A relatively ‘clean’ process
• A proven method − highly durable and reliable
• Minimal additional loading, no structural reinforcement required
• Conforms to EOTA and other international standards, BBA−certified
• No need for evacuation of residents or suspension of production (solvent−free formulations)
• Permeable to water vapour
