Determination of Adhesion of Silyl Modified Polymer Adhesives to Wooden Façade Cladding – Case Study

Abstract

Adhesives are currently very often designed specifically for bonded façade systems. The potential of bonded joints should be studied and described in more detail and verified through experimental measurements. Presented results are therefore focused test methods intended for vented wooden façade systems with bonded joints. For the purpose of tests two types of silyl modified polymer adhesives intended for structural bonding were selected, however, only one of them is recommended for façade systems. The spruce profiles and three types of façade cladding (i.e. Cement-bonded particleboard - Cetris, Siberian larch and Wooden Plastic Composite - WPC) represent the structure of vented façade. The focus was on experimental verification thus all test procedures are following relevant European technical standards. The adhesive bonds were tested in adhesion of the surface finish to the substructure as well as in tensile lap - shear at a temperature of (20.0 ± 3) °C and a relative humidity of (55.0 ± 10) %. The performed tests showed the equivalence of the bonded joint system for ventilated facades in comparison with mechanical joints. During the tests appeared differences in stability and failure behaviour between the adhesive systems as well as within the sheeting material. Another conclusion arising from the series of tests is the fact that the use of a wooden substructure for ventilated facades is not a limiting element for the whole system and is a more financially viable option in comparison with an aluminum or steel substructure.

V posledních letech vzrostl význam problematiky lepených fasádních spojů. Tento článek řeší tuto problematiku především z hlediska přídržnosti lepícího systému k obkladům ze dřeva a na bázi dřeva (WPC). Zvolená metodika zkoušení vychází z evropských technických norem a standard. Samotné zkušební postupy byly modifikovány tak, aby co nevěrněji prezentovaly skutečné parametry prostředí, v nichž se fasádní systémy nacházejí. Výsledky zkoušek prokázaly, že materiály ze dřeva a na bázi dřeva jsou vhodné k lepení, neboť lepený spoj eliminuje některá pnutí vznikající při exponaci materiálů vnějším klimatickým vlivům.