| Existing Substrates | Application Requirements |
| Surface finish smooth | 3 to 5 mm in 1 coat |
| Roughcast | 5 to 8 mm in 2 coats |
| Some cracks | Embed a minimum of 500 mm wide layer of TV10 MESH over the cracks into the 1st coat of PARINTER, followed by a 2nd coat of PARINTER (1) |
| Frequent cracks | Apply to the whole façade a layer of TV10 MESH embedded into the 1st coat of PARINTER, followed by a 2nd coat of PARINTER (1) |
(1) These measures spread the stress of the fracture, but there is still a risk of cracking if the substrate continues to move.
Where there are different substrates they must be isolated from each other and the joint treated with acrylic mastic, carry out the finish on substrates which have dried for a minimum of 24 hours.
SUMMARY OF PRELIMINARY IDENTIFICATION TESTS FOR PAINTED FACINGS
1. Appearance
The application of PARINTER RENOVATION is only possible if the substrate facing is in good condition, sound, no flaking of the surface coating and is well adhered to the substrate. Check that there are not several layers of paint or thick acrylic coverings or a thick acrylic covering over a painted surface e.g. something that could cause delamination.
2. Responsitivity to water
- Wetting: Pour water on to the façade. The facing should become wet and leave a wet mark. If water runs off with a pearling effect without wetting the substrate, it is likely the surface has been treated with water repellent and is therefore incompatible. Do not proceed with the application of PARINTER RENOVATION.
- Soaking: Place a wet sponge on to the façade for approximately 30 mins and note how the surface finish reacts: there should be no change to the surface and there should be no softening or bubbling of the painted surface.
3. Flexibility (resilience)
It is important that the surface coating is not flexible. If there is any uncertainty, cut out a 50 x 50 mm section of facing and bend it slowly at 20 ºC. If the product remains pliable (bends without breaking), it is incompatible.
4. Surface cohesion when dry and wet
Dry - Fully score the painted surface with criss-cross incisions, both when wet and dry.
Wet - Use the area that was soaked for 30 mins with a sponge detailed in test 2 and fully score the painted surface with criss-cross incisions
Paint: Criss - cross pattern of 2 x 2 mm
Thick acrylic covering: Criss - cross pattern of 5 x 5 mm
A minimum of 2 tests should be completed for both, wet and dry tests. The location of the tests should be spread across the building at both high and low locations of the facade.
After brushing the test surface and removing loose parts, apply a well adhered strong adhesive tape to the test surface areas and then pull off the tape, observing the degradation. No criss cross squares should come away (see Technical Data Sheets and Identification sheet).
5. Burning
Heat the painted facade with a blowtorch or heat paint stripper.
If the facing softens or burns with a strong smell, it is a painted finish; otherwise it is a mineral finish
(whitewash, silicate coating) and is incompatible.
Scrape the heated facing with a paint knife and examine all the layers right down to the substrate to check on the bonding of the paint.
6. Adhesion
If any of the previous tests 1- 5 did not work DO NOT carry out this test as incompatible surfaces can not receive PARINTER RENOVATION without the use of pinning a full layer of TV10 reinforcement mesh and installing mechanical anchors through the mesh across the whole façade to a Parex specification.
If the surface is satisfactory:
On a clean, dry substrate, embed a 1000 x 500 mm piece of 355 AVU reinforcement mesh into a 4 – 5 mm layer of PARINTER RENOVATION leaving 100 mm free at the bottom. Smooth the surface, then clean away surplus material away from the perimeter of the sample.
After leaving to dry for several days, pull on the mesh to exert a pulling force by rolling the free part of the mesh round a broom handle.
- Positive test: The render on top of the mesh breaks off and the mesh is completely clean. The render remaining on the substrate is intact, adhering without any initial cracking.
- Negative test: the render comes off and parts of the substrate detach, caught up in the mesh due to a lack of adherence. The render adhering to the substrate has initial cracking or cracks.
Please note that if all the tests carried out are positive, any suspect areas to the painted surface discovered during high pressure washing (140 bars) must still be fully stripped or local defective areas removed back to the render or masonry substrate.
