Expanding foam worked nicely. I used one that doesn't get super hard. And I cut it with a multi tool with the spatula tool connected. Cuts very cleanly.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local