Express Course

How to repair mechanical damages in plastered insulation

Our guidelines to repair mechanical damages in plastered facades insulated with EPS boards.

Know upfront

Tools needed

a stainless steel trowel
a pressure washer
a PU foam adhesive with a gun
reinforcing mortar & mesh

CRUCIAL to know

add fasteners if damaged area is 0.5 m2 and more
wait 24h, after washing the facade, to apply the CT99

PART 1: START WITH WASHING & CLEANING

Start with washing the facade

Then apply fungicide concentrate

CLEANING THE SUBSTRATE WITH CT 98

Before any repairs, the facade must be washed and cleaned from dust and dirt with CT 98 agent and then left to dry completely. The best washing results are provided by pressure washers, but you can also use a brush or a garden sprayer.

Wash the facade with a pressure washer and CT 98 agent diluted with water. The dilution ratio can be from 1:1 to 1:4, but it should be tested each time. For cleaning you can use also a garden sprayer or a brush,
After 10 to 15 minutes wash the surface again with clean water.

Once the washing is complete, make a detailed visual inspection of the façade.

Protection against fungi and algae

If there is any bio contamination, you have to remove it prior to repairing job. When the facade is washed and completely dry (after approximately 24 h), remove fungi and algae using the fungicide concentrate CT 99.

PART 2: LOCAL STRUCTURAL DAMAGE

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Local damage in plaster, reinforcing layer and insulation material

If the mechanical damage affects the plaster, reinforce layer and insulation on small areas and there will be no need to repair the entire facade – cut the damaged fragments out.

In the case of larger mechanical damages, any cavities in the insulating layer should be filled by using PU adhesive CT 84, or by cutting out the damaged area and replace a part of the insulating material. If the damaged area is 0.5 m² and more, additional mechanical fixings must be installed. Then, you must apply the reinforced layer over the damaged area by using fibre glass

Cut out the destroyed fragment…

deep into the wall.

Replace it with a new insulation material.

Fill in gaps with PU foam.

Then apply the reinforcement…

and prime when the mortar is dried.

Then apply the same plaster.

PART 3: A GAP AND CRACKS IN PLASTER

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Slight damages in THE PLASTERED SURFACE

If only a small area of the plaster is destroyed, remove all loose pieces of plaster. Fill the hole with CT 100 or CT 87 reinforcing mortar and embed a piece of reinforcing mesh CT 325 with 10 cm overlapping. Wait until the mortar is completely dry and apply CT 16 primer. Then you can apply the plaster. Optionally, the entire facade can be also painted.

If the damage is done to a small area

and only the plaster is affected

fill the destroyed part with mortar...

and embed the reinforcing mesh.

Then apply the same plaster.

OUR TIPS & Tricks FOR PROFESSIONALS:

How to tackle cavities under insulation without cutting out large parts of plastered insulation?

If there are cavities under EPS boards and you do not want to cut out large parts of insulation, make local injections with PU foam adhesive.

Drill some small holes through all insulation layers to reach the wall. The drillhole can be as wide as the diameter of PU foam gun barrel. Inject the PU adhesive CT 84 into the drilholes.