Replacing supporting posts

[TimmyR]

Hello,
We are after some help regarding our barn conversion, which is approx 200 years old although different parts of the property are different ages. In the living room we have posts which appear to be supporting the floor beams above. Three of these posts are essentially outside and so open to the weather. When painting these recently I found not an inconsiderable amount of rot. Which for now I scraped back to what is hopefully good wood and repainted. Because of this I am now considering what would be involved in replacing these.

As I said above these seem to be supporting the main floor beam which I presume is subsequently supporting the floor joists above. So not an inconsiderable amount of force.

I am a carpenter but this is beyond what I have tackled so far. I will get more opinions but if anyone has experience in this and could let me know the process for replacing the posts that would be a great start. I presume it would be to Acrow the beam/ beams above and cut out the post, which has a brace presumable mortise and tenon, which is currently behind the ceiling and wall plasterboard.
Any tips welcome and thanks in advance.

 

[a twig]

Definitely not an expert but if the damage is only at the base I’d be tempted to look at chopping out the rotted section and scarfing in rather than replacing the whole thing.

Would still need propping with acro etc but would minimise the thrashing around indoors

 

[malcolm]

Are the posts actually structural? They look like they are old but the beam above looks new and there are no signs of the peg at the top that you would expect in a mortice and tenon joint. Is the beam above really a beam or is it concealing a whole bunch of steel? If it was me I would have put the structure on the newly built wall.

The deterioration is a problem. The paint is shiny so it is likely waterproof. The wood is old and has cracks and stuff. Water gets in through the cracks and can't get out because of the waterproof paint so the post rots. Much better to strip the coating off and allow the wood to breathe.