Specification for sealing building envelope walls

Specifications for sealing the walls of a building envelope lined with “Bereshit” absorbent stone  produced by Ekarstein

Building envelope walls, specification for sealing an absorbent stone covering such as “Berashit”, silicate and natural stone

For buildings where tiles have not yet begun to fall, for these see a separate specification. Falling exterior wall cladding – causes, countermeasures

introduction:

Exterior covering of a building of absorbent silicate stone requires high-quality sealing up to 100% prevention of water penetration. Sealing that is less than perfect will allow the penetration of rainwater which will “travel” and leave where possible and which will penetrate the apartments inside and cause the paint to swell and the plaster to crumble in addition to bad smells, and worst of all – will crumble the adhesives and plasters that connect the stone to the wall and cause it to fall, which poses a danger of damage to property and people up to Life-threatening.

Specification for sealing building envelope walls lined with absorbent stone www.denber.net

Building envelope walls, specification for sealing an absorbent stone covering such as “Berashit”, silicate and natural stone

 The requirement:

A system is required to perform a sealing coating for many years, repels rain that meets the target test according to the standard for the entire building envelope, resistant to water and natural erosion and UV resistant. The coating will be carried out after proper treatment of cracks, expansion seams, gaps between the stones, in the horizontal and vertical joints in wall joints, around the windows , balconies and various elements in the building such as concrete, aluminum, etc. Also, the coating will be smooth and sealed and prevent water from passing through, the coating will be resistant to standing water. The appropriate coating is a polyurethane monolithic coating on a UV-resistant water base, on a layer of a suitable thin penetrating primer from the same family. At the end It should be obtained from a sealing membrane of the surface of the stone surface and the recesses and to bridge over capillary cracks and water-absorbing nozzles in the columns and in all the areas of the sealed stone.

Area preparation:

• Washing with water at a pressure of 150-160 at to remove dirt and dust and parts filling loose voids and waiting for complete drying.
• Completing missing joints and repairing existing ones in intervals of 4 mm or more.
• Sealing all the narrow spaces (less than 4 mm) between the stones where it is not possible to apply caulk, the screws and the cracks with  a certified two-component transparent polyplex 225A  with Cabosil. If there is not a gap of at least 4 mm, polish and expand to at least 4 mm.
• Sealing all the nozzles by applying a brush with 225A to seal the nozzles in the nozzle.

Specification for sealing building envelope walls

Building envelope walls, specification for sealing an absorbent stone covering such as “Berashit”, silicate and natural stone

Penetrating primer layer:

• Aqua Flex polyurethane primer  – water base, spray from 4 directions, until full impregnation. It is also possible and recommended, provided that the smell does not interfere, to coat the walls with “ siloxane 290 “, which is 5 times more resistant to weathering compared to water-based sealers.

 Coating layers to obtain a fully sealed film:

• Aqua Flex Polyurethane  – water base, spraying from four directions 2 layers 6-24 hours apart, for full coverage and a uniform opaque film. If there is no coating sequence, a third layer must be sprayed.
• It is also possible and recommended, provided that the smell does not interfere, to coat the walls with ” siloxane 290 “, which is 5 times more resistant to weathering compared to water-based sealers.

For an expensive and high-quality sealing system that will last for many years:

Base :  Danbergloss sealer  – two-component solvent polyurethane

Upper:  Dunbargloss Clear  – a transparent polyurethane coating that seals the top. And if it’s colored, then  Dunbargloss Glaze – Polyurethane Glaze.