Exposed roof timbers

[cumbrian]

I'm coming towards the end of laboriously cleaning up the trusses and purlins in an old barn that we're having converted. Of course, if someone had done thier job properly, they could have been grit blasted before the new roofing felt went on..... still, at least I've justified buying a Rotex sander to do the job! Most of the timbers will be visible but out of reach.

I've now got some relatively nice looking old pine timbers exposed. My initial thought was just to leave them as they are - the barn is for holiday lets so minimum ongoing maintenance is a high priority. However, it has been suggested to me that it would be a good idea to seal them. From a standpoint of total ignorance, here goes:

I don't want a gloss finish, preferring to keep the timber looking as natural as possible.

Would a sanding sealer be suitable? I'd be looking to spray, so my strong preference would be to use something water based. (I've been spraying the cleaned timbers with water based Boron woodworm solution.)

Would it serve any useful purpose, such as making future routine dust removal easier, and in particular making it easier to remove any muck deposited by further trades, such as plasterers? I'm seriously considering covering as much as possible with pallet wrap (like big cling-film) while the mucky jobs are being done - any likelihood of a sealer reacting with this?

Or am I just being advised to waste more time and money?? :?

Any help very gratefully received!