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DuraBase CI+Crack Isolation & Decoupling Membrane

10 Meter
With shipment MyHermes for £7.69
Sales price £74.04
Price / kg:


1. Cracks in the subfloor 

When renovating older floors, cracks can be present in the subfloor, making it impossible to install a safely watertight new tiled surface.

2. Stresses in the subfloor
In the subfloor beneath the flooring it is possible for tensions to appear in materials, depending on the design and the kind of materials they are. These can then be transferred to the tiling and cause cracks to appear in it. For instance, with concrete, even after six months or after many years
of expansion and contraction, deformation can occur. Cement and hot screed surfaces can also deform after tiles have been laid. Chipboard or plywood too can deform considerably due to absorption of moisture. 

3. Damp from the subfloor
When laying on top of anhydrite screed, residual moisture from the screed itself can collect under the tiles and damage the adhesive layer.


DURABASE CI++ matting in conjunction with tiles serves to decouple the tiles and bridge any cracks. It also allows water vapour pressure to be compensated for if there is residual moisture.
DURABASE CI++ decouples the flooring from the foundations. Any small cracks can also be bridged so that they do not affect the tiling. This makes it ideal for renovation work.

At mat joints we recommend the use of WPF sealing tape.


1. The floor making up the foundation must be free of any material that would impair adhesion. It must be level and able to bear weight. Any evening out to be done must be completed before DURABASE CI++ is laid. The adhesive is chosen depending on the nature of the foundation. The adhesive must bond to the foundation and to the backing fleece of the DURABASE CI++ mats. For most surfaces a water-based C2 flexible mortar can be used. The mortar is applied to the foundation using a serrated trowel (4 x 4 mm). Important: do not use larger sized serrated trowels
or the decoupling effect of the CI++ matting will be impaired. This in turn will create a crunching sound under foot.

2. Having been cut to size, the rolls must quickly be laid over the entire surface with the fleece backing on the adhesive. The rolls can be pushed into place using a roller or other suitable tool. Make sure this is done before the adhesive is dry. To avoid damage to the rolls being laid, it is recommended that they be protected from loading by laying boards on them. Other protective measures may be necessary, too, e.g. protection from direct sunlight or rain in outdoor locations. Any water collecting in the texturing must be removed before applying thin-bed mortar.

3. Always cover over junctions between mats with DURABASE WP or DURABASE WPFB tape.

4. As soon as the DURABASE CI++ matting has been laid, tiles can be laid on top of it using a thinbed technique and a thin-bed mortar appropriate to the flooring. Practically, it is advisable to apply mortar to the round depressions in one working step and then apply thin-bed mortar and roughen
it in another. The work can also be done in such a way that the application of the top mortar layer only starts after the initial application has hardened. The tiles must be embedded in the mortar to cover the entire surface. The depth of the serrations on the trowel must be appropriate to the tile format. Make sure this is all done before the adhesive is dry. For flooring out of doors, the laying of tiles should only begin after the mortar for the CI++ underlay has properly hardened. Where expansion joints are used to delineate areas, edges and junctions, professional regulations
should be observed. Flooring outdoors, floors using large-format tiles or any flooring subject to heavy loading should be laid using a combined installation procedure.

By reason of design DURABASE-CI++ mats are not suitable for laying under thin or large-format floor tiles (”slimline tiles”). There is a risk of them breaking. In addition, small-format tiles under 50 x 50 mm must not be used either. For all products and materials, the following applies: The suitability of the material with regard to the expected mechanical loading and chemical exposure must be investigated carefully in
each individual case. The generally recognised rules of good engineering practice must always be observed! 

DURABASE CI++ – when laying underlay mats on balconies or patios in high summer temperatures, the mats need to be protected by some means in order to prevent them becoming unglued or buckling while the adhesive is hardening. For better results when installing the mats, it is
better to lay them in the cooler hours of the evening and then to lay tiles on top the following morning.

Data sheet downloads. The latest versions of the technical data sheets are available on the internet at If need be, you can also order them in printed form, of course.

(Read our detailed installation instructions by downloading the PDF file - available via the data sheet tab on this page)

Underlay mats for decoupling and waterproofing tiled flooring


PRODUCT: CI decoupling mat ++
MATERIAL: Textured foil = PP, Backing fleece = PP, Mesh = PP
MATERIAL THICKNESS: 0.5 mm approx.
LENGTH OF ROLL: 5 / 10 / 30 m
COMPRESSIVE STRENGTH: 0,37 N/mm2 approx.
TEMPERATURE RANGE: – 40 °C to + 80 °C
COLOUR OF MATS: Textured foil = yellow, backing fleece = white, mesh = green
MATERIAL PROPERTIES: Resistant to chemicals, decay, fungus und bacteria
APPLICATIONS: Underlay matting for decoupling and compound sealing of tiled floors



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