Flooring and tiling adhesives - Norcros
NORCROS Adhesives, manufacturer of tiling adhesives, grouts and surface preparation products, says it offers a great solution for tiling on to anhydrite (calcium sulfate) screeds.
Norcros Pro Gyp-Base Adhesive is designed for fixing tiles to the Norcros Pro Gyp-Base Fast Track Sealer. The adhesive can be applied once the sealer has dried. It’s said to be an off-white cement-based, flexible, fibre-reinforced, thin bed cementitious adhesive specially formulated for fixing fully vitrified porcelain, ceramic and natural stone tiles to the anhydrite screed-sealer.
The adhesive has a setting time of three hours at 20deg C, permitting early trafficking of the tiled installation, says Norcros. ‘It also has excellent thermal ageing properties making it suitable for use on heated floors.
‘The Pro Gyp-Base Fast Track Sealer and Pro Gyp-Base Adhesive system provides a fast-track tile installation system on to anhydrite screeds, without detracting from the overall screed strength and it’s suitable for use on heated or unheated anhydrite screeds.’
Screeds must have reached a relative humidity of not greater than 95% (generally achieved seven days after the screed has been poured) before the system is applied. The sealer system comprises a two-part water-based resin primer, a hybrid moisture suppressant and a gritted primer.
It’s supplied in a 15kg kit which reportedly contains everything required to prepare and seal about a 25sq m area. An initial coat of primer should be allowed to dry for a minimum two hours before a second coat is applied at right angles to the first to ensure 100% coverage.
This is allowed to dry for 24 hours. The moisture suppressant and gritted primer applied to the primer coat require three hours drying time before tiling can commence.
‘This system from Norcros Adhesives is designed to tackle a key issue associated with the increasingly popular anhydrite screeds, namely extended drying times, which can be up to 80 days for a 60mm screed,’ says Mandy Searle, head of technical services at Norcros Adhesives.
‘It provides a system solution, which is a real-time and cost-saver onsite for flooring contractors and tile fixers.’
The benefits of this system have not gone unnoticed with Norcros Adhesives’ customers in the housebuilding sector, where the ability to offer a tiling solution for anhydrite screeds is viewed as a big asset, according to the company. It says it’s now working long-term with Barratt Homes on tiling over anhydrite screeds.
‘We were very impressed with the ability of Norcros Adhesives to provide solutions for problem areas in floor tiling,’ says John Adams, group procurement director of Barratt Homes.
‘Anhydrite screeds are being used increasingly in the housebuilding sector, owing to their speed, cost-effectiveness and more environmentally-friendly composition. So, we need partners who can work with us on this and other new construction technologies which are increasingly being used in the housebuilding industry.’