Choosing the right sealant and adhesive for plastic fittings is important, protecting the products and your installation, explains Fred Gardner, Technical Sales Manager at McAlpine Plumbing Products.

Plastic fittings are an integral part of most bathroom, kitchen, and toilet installations, and play a crucial role in stopping noxious and toxic gases entering a home or building. In fact, plastic fittings are so popular that some manufacturers produce thousands of products, all designed to bring quality and performance to plumbers across the world.  From plastic traps and WC connectors to multi-fit waste fittings and air admittance valves, there is a product range for all applications.

Although the products are produced to stringent quality standards, it is important that certain chemicals are not used on plastic fittings, in particular certain acids. Here are some top tips for choosing the right sealant and adhesive.

Smell test

The name ‘acetoxy’ comes from the fact that a compound releases acetic acid. You’ll know it from the strong vinegar like smell while curing. When acetoxy silicone is used with a fitting, it causes a degradation in the plastic which leads to splintering and breakage. In simple terms, it’s plastic decay. This breakdown and the subsequent stress cracking leads to leaks, which can cause major issues for tradespeople and callbacks are almost certain. So, watch out for that vinegar smell! Choose a sealant and adhesive which has a low odour and is not acetoxy.

Don’t be afraid to try something new

Polyurethane and silicone sealants have been popular for years for good reason – they can be used in a variety of conditions, have great elasticity, and are cost-effective. These sealants are perfect for sealing bathrooms and windows. But hybrid polymer sealant and adhesives are a great alternative – they are true all-rounders in the building trade.

Hybrid polymer adhesives and sealants are hardier than silicone and capable of withstanding extreme conditions. They have brilliant cohesion strength and will stick to a wider variety of surfaces (including aluminium, galvanized and stainless steel, zinc, copper, natural stone, treated wood, glass, and much more). Hybrid polymer sealants and adhesives can also be super flexible – in tests, these hybrid polymers have been shown to stretch up to 350% while many silicone alternatives may only stretch to around 280%. Hybrid polymer sealants and adhesives cure quickly and will dry completely smooth – and they don’t damage most synthetic materials.

Save time with hybrid multi-purpose sealants and adhesives

Hybrid multi-use sealants and adhesives can save you time and money. It’s worth looking for a sealant that is suitable for timber, metal, concrete, and for sealing expansion and construction joints. For many tradespeople it’s common place to need to seal baths, sinks, vanity units, and toilets, but also need an adhesive for tiles, mirrors, metals, wood, stone, concrete, marble, and brick, so a sealant and adhesive that can deal with all these will save time and money. Sealants that also contain a fungicide are even better as they can be used on wet surfaces to combat mould and bacteria growth.

Check it is safe to use

Check the sealant is safe to use and contains no solvents or isocyanates (in many silicone sealants) which can cause skin irritation and breathing difficulties and have been linked to asthma. Hybrid polymer sealants and adhesives are solvent-free, making them far better for the environment, especially where rain encourages run off. Also make sure that once the product has cured it has good abrasion, oil, and solvent resistance.  Check it has also been tested to the highest standards to make sure it’s not only going to do the job, but that it will last.

Choose a brand you can trust

There are lots of sealant and adhesive brands on the market, but don’t just pick the cheapest, pick a brand that’s been around a while and that you know you can trust. Some companies will provide support, information, or installation videos, and it’s worth looking for those brands that offer a wide range that, when used together, work perfectly.