How to restore an old coat affected by cracks and crazing?

PROBLEM: restore an old coat with cracks

Considering that in Italy coat systems have been running for the past 40 years, we find ourselves increasingly più often faced with interventions performed when the technology had not acquired the experience of today. The più defects; visibilisono due to improvised poses, and manifest themselves with cracks and crazing at the joints between the panels and with the so-called ": mattress effect" ;, usually caused by a lack of bonding. Even small defects of this type can cause the entry of meteoric water over time and subsequent swelling of the coating.

SOLUTION: restoration of cracks and protection of the coat

1. Treat any mold with algicide solution and BIOCID fungicide, before applying a mold-resistant finish cycle.
2. Scrape off any small portions of the raised or peeling coating.
3. Check for any netting points in the net in order to check the adhesion of the leveling layer to the insulating panel.
4. Check the tightness of the support panels with the replacement of any panels that are not perfectly anchored or in the process of being detached.
5. Foam any cracks or gaps between the panel and panel with a suitable polyurethane foam.
6. Restore any deteriorated seals, meeting sections with frames, frames and / or dimensions with special sealant.
7. Apply a coat of fixative all& # water, micro-emulsified, acrylic, strong penetration, appropriately diluted FIXACRIL with a brush or roller. Yield about 10-15 m2 / L.
8. Re-nail the entire surface with fasteners of appropriate length, at a rate of at least 6 nails per m2.
9. General leveling of all surfaces with ELASTORAS applied by two coats. With interposed net for coat in fiberglass 161-A speckled with 160 gr / m2 alkali-resistant.
10. In correspondence of the openings for doors and windows, provide an additional reinforcement of the reinforcing mesh in an oblique direction (45°) with respect to the openings, to avoid the formation of cracks at the corners where c& # 39 ; è the greatest concentration of efforts.

Realization of the finishing layer

Once the shaving is completely dry, the finishing layer is applied to protect the entire system. The finish, in addition to giving the desired aesthetic appearance to the system, protects it from the action of atmospheric agents, ensuring durability over time.
The finishing cycle involves the preparation of the finishing paste plaster, selected from the range of Paulin products of Acrylic, Acrylic-Siloxane, Siloxane lines, with the coloring and grain size selected according to the specific requirements of the project .

E& # 39; a clear finish color or a light reflection index (Y) greater than 30 is advisable. Strips d& # 39 should be provided for vertical and horizontal interruptions so as not to highlight defects deriving from filming of applications. The finishing plasters in paste that can be used, compliant with EN15457 (resistance to the growth of fungi) and EN15458 (resistance to algae growth) are: LAMATO COAT PREVEN, CLASS COAT PREVEN, SANO COAT, SILOX COAT.& nbsp;