When you cut and join laminate benchtops is it enough to just use PVA glue between the joins? I heard a horror story of water getting into the join causing the benchtops to swell. Would it be better to use silicone between the joins?
I am in the planning stage of renovating my kitchen and just covering some knowledge gaps.
Stuardo either will work as a seal a good smear of pva or silicon clamp up and wipe / scrape off excess. I assume you will biscuit the join to stop vertical movement and use benchtop joining clamps to hold joint together for mechanical part of joint.
I would use PVA that is suitable for outdoor use just in case you do spill something on the join.
As per our benchtop manufacturer Kaboodles instructions for their products, the use of PVA glue and benchtop joining clamps are required. For benchtops over 30mm thick, Kaboodle recommends the addition of biscuit joiners. For the PVA glue, I would suggest following @Brad's advice and use an exterior grade similar to Selleys 250ml Aquadhere Exterior Adhesive.
You might be interested in a convenient benchtop join kit supplied through Kaboodle with everything you need for the job.
Please let us know if you require further information or had any questions.