Professional Acrylic, PU, MS Polymer and Bituminous Sealants

For window frames and glass use neutral silicones, which do not attack materials and bond well to glass, aluminium and most building materials. Acetic silicone releases acetic acid as it cures, so it should be used on surfaces that are not affected by it, such as ceramic and glass, but not on marble or sensitive metals. For joints that move a lot, consider a PU or MS Polymer sealant.

For bathrooms, kitchens and sanitaryware, use a silicone designed for wet areas, with good resistance to mould and condensation. Acetic silicones for bathrooms have a pungent smell while curing, but are suitable for ceramic and glass. Before applying, clean the joint and remove the old silicone. On surfaces such as marble or stone, check that the product is compatible.

Acrylic sealants can be painted and are used for interior joints between wall and frame, cornices or joints under little stress. They do not cope well with continuous water or strong joint movement. Painters' sealant, such as those in the catalogue, is designed to be finished with paint. Before painting, wait for the stated curing time, otherwise the paint will not adhere well.

Polyurethane and MS Polymer sealants are elastic and paintable, suited to joints that expand and contract, such as those between panels or between different materials. Polyurethane should be painted only after full curing. On joints subject to movement, respect the width and depth stated by the manufacturer, and use a backing rod that limits adhesion to the base.

For roofs, roof flashings and joints exposed to water, use bituminous sealants, which adhere to metal and cementitious surfaces and resist moisture. They are often dark and not very attractive, so use them where they are not visible. Before applying, clean the surface of dust and moisture and respect the minimum application temperature stated on the data sheet.

For stove and fireplace seals, use heat-resistant sealants, which do not deteriorate with heat. Not all silicones withstand high temperatures: check the maximum temperature stated on the data sheet. For closing flue pipes, check the suitability of the installation and local regulations, as the sealant alone does not replace the required checks.

For construction sealants the EN 15651 series applies, which covers products for non-structural use in buildings, with tests for elasticity and adhesion. On the data sheet look for the CE marking and the declared class, especially for façades and window frames. If the sealant is used on water systems, check that it is marked as suitable for drinking water.