Rodent proofing garden room floor?

[OxfordBlue26]

After what has been months and months of groundwork (endless digging, 15 tonne of rubble shifted, tree removed, raised beds made from railway sleepers relocated...), I have finally begun construction of my 8m x 4m garden room. For the foundations, I decided to use EasyPads - I am building on a slight slope and am also ~100 metres away from the road, so this seemed like the best/easiest option. I've almost finished the frame for the timber floor - just a few more joists and then noggins to fit, before I insert PIR insulation. However, before I do that, I am wondering whether I should rodent-proof my floor somehow (we were round at my parents last week, where we discovered that they had a large rat living under their summerhouse!). The void under my timber floor is 10-20cm, so my initial thought was to somehow secure the perimenter of the floor. However, it seemed like there was no simple way of doing this, and I was concerned that any rodent mesh in contact with the ground would rust/break down over time, or creatures could dig under it. I have therefore decided on the more time-consuming and costly option of securing the lower section of each of the openings in my floor with rodent mesh (meaning that below each piece of PIR insulation there will be mesh). I've used 6 x 2 timbers for my floor and plan to use 100mm insulation, so I have a little bit of room to play with under the insulation boards.

Is there a better option?! Or am I worrying unnecessarily (are mice/rats likelty to chew PIR insulation?)?! Any thoughts/ideas very welcome!

 

[mrrusty]

I did a very similar construction https://community.screwfix.com/threads/garden-room.256842/

I had the same fears as we have rats around near the pub next door. I used a perimeter rat mesh on the inside of the outer beam and I buried the bottom hoping that rusting out of the galvanised mesh would take a while. I used OSB under the PIR in each of the bays (you can just see some supporting battens in one of the pix) I hoped that with plastic over the ground, mesh round the edges and OSB would be enough - so far, so good (2 years). I only have 50mm PIR in the floor and an airgap between the PIR and the flooring chip through which a water pipe runs.

I figure that if they do take up residence there will be an obvious hole through/under the mesh which will be the optimum spot for a trap/poison.

Plan C would be to concrete block the gap at some point in the future if necessary.