[Plugin: WooCommerce – excelling eCommerce] Halting Orders over 150lbs

Although it seems a bit overkill for such a minor change, our Table Rate Shipping extension is able to handle this. You can create shipping zones with that, where in you define areas to ship to and can link prices to those zones based on weight, quantity and more variables of products.

When you don’t set up a shipping method for a specific range of weight, the user will be prompted with the message that there is not applicable shipping method available and is requested to contact the store owner.

You can probably do this same setup with any plugin or extension that allows you to define shipping methods based on weight, Table Rate Shipping is the most flexible.