Finish for outdoor timber ceiling

I have a 7m x 7m outdoor awning that will have for a ceiling the Studleys tongue in groove hardwood flooring (yes I know it's heavy) and I want to know what would be a good finish for this.

I was originally thinking intergrain DWD sealer and clear gloss, but it is really expensive - I used it on the cedar skylight.

I was also thinking clear marine varnish - dear as too.

I was also starting to show a lot of interest in the other thread on cellulous lacquer versus acrylic lacquer - CL won't last. AL just might be okay.

The timber is underneath an awning that has metal roof over - the ceiling will be 3.5 to 6m up and I don't want to apply and oil that I have to keep fixing every 6 or 12 months cuz it is a scaffold job.

I want the timber to resemble a timber floor in finish - would i be better off applying floor polyeurethane?

Just about to start this project, so would like to do it right once not repeat or change because of a bad approach.

I will be putting the ceiling up in panels 1.2m x 1.2m and will prepare them before fixing them up so can do them both sides and in an appropriate environment - can spray or brush apply finish.

I don't mind the clear plastic look - I detest the yellow or flakey look of a bad finish.

I will pay for a better product if it is good value but can't see the sense of spending a lot on a product that is no better than another less expensive one.

The ceiling goes in underneath this awning - it currently has a roof sheeting and electricity but the ceiling will be "v" grooved T&G running from the gutter up towards the peak in lengths of 1.2m - essentially panels spanning from purlin to purlin.

G'day TJ

I have finished all of the exterior visible timber on my place - including decking - with Sikkens Cetol HLS (Pine colour, the least coloured). Yes, another dear one, but worth it in my opinion. Its oil based with a little pigment which helps longevity. Its very easy to use, doesn't need a sealer, soaks in well and doesn't seem to mind if recoated earlier than recommended. 2 coats would prob be ok or 3 is fine and still looks very natural, more so than Intergrain. Unless you're getting sun on the job - unlikely for a ceiling I would think - I doubt you'd have to ever recoat. Mine's been there 6 years and looks great. I've also used this stuff inside on everything too; doors, architraves, skirtings and get plenty of positive comments. Yes, I am a fan!

The timber in the pic is kwila (merbau) so is fairly dark. I've also used it on various aussie hardwoods, meranti, oregan

As its out of the rain & direct sunlight any of the indoor finishes would be good.