Guidelines for thermal insulating walls with URSA® HYDRO polystyrene panels

Required tools and materials:
1. Expanded polystyrene panels URSA® STYRO

Guidelines for thermal insulating walls with URSA® HYDRO polystyrene panels

Step 1
Base preparation: base must be dry, capable of bearing load, and clean (refill possible losses, degrease and cleanse the base, for best results sanding bases must be primed); surface deviations must not exceed 10 mm as measured along a 2-meter rule, otherwise the base surface must be evened up.

Step 2
Using adhesive, fix URSA® STYRO panels upwards from the starting batten, with longer edges oriented horizontally. Subsequent rows should be fixed in passing order.

Step 3
Works should be performed at the temperature above 5°C, at rainless weather.

Step 4
A panel must be pressed to the wall and slid to already fixed panels, and set with a long float so as to obtain an equal plane. Later pressing of fixed panels, or moving panels after a few minutes is forbidden.

Step 5
In case of bases of low load bearing capacity (old plasters, scaling or falling away when hit with a hammer), URSA® STYRO panels must be additionally mechanically fixed with plastic pins (usually 24-48 hours after fixing panels). The pin length must be selected so that its part sunk in the wall is about 6 cm long in case of full wall, 9 cm in case of walls of structural clay bricks or light concrete. The number of pins is 4–6 pieces per square meter, and 8 pieces per square meter in the edge zone.

Step 6
Reinforcing layer must not be made earlier than after 3 days from fixing the polystyrene foam panels. A 3-mm mortar layer should be applied with a long float with 10–12-mm pitched teeth, beginning with the corner of the building. Next sink the net, and with the smooth side of the float even up the surface, placing additional adhesive where the net is visible. The net must be applied to fresh layer of mortar, keeping in mind that it should stretch out beyond the corner by 15 cm, then it should be bent and sunk in the adhesive on the other wall of the corner. Neighbouring net sheets should overlap by 10 cm.

Step 7
Corners of window openings should be reinforced with 20 × 35 cm net cemented to the polystyrene foam. Protect vertical edges against mechanical damage by gluing perforated aluminium L-bars before applying net.

Step 8
Plaster should be laid not earlier than after 3 days from sinking the net. Works should be carried at the temperature of 5°C to 25°C, at rainless and windless weather. All subsequent layers of plaster are applied with “wet on wet” method, i.e. applied to underlayers yet unset.

Step 9
The thickness of URSA® STYRO insulation should be consulted with a designer.