bryce

The load is only the insulation, the 2x6's, drywall. Is that really a load or cosmetic?

nealtw

If you look at the weight if the floor upstairs the nee walls the drywall the flooring the funiture or what have you and people that might be up there. Half of that weight is hopefully landing on bairring walls. The other half is landing on the 2x6s, divide that in half for each side of the house. The nee wall replace what would have been angle bracing to the center of the rafter from the bairring to prevent sag in the rafters so what ever load from the roof is now landing on the 2x6s. This calculation does not want to be close. If it won't be strong enough to carry 1000 lbs of drywall it is just simply not strong enough.
http://www.homeadditionplus.com/attic_info/How_to_Finish_an_Attic.htm

bryce

Hi Neal. Like i said nothing has change in the house, the article you mentioned is about a conversion. If fact much less weight now. I removed huge amount of material from the flat ceiling including drywall and stringers, ceiling tiles. It has been used like this for years. Inside the space of the knee wall was also a massive amount of loose insulation.
All the weight was on the beams before - now it is more supported by 2x6" and the new structure. It will 26x5= 125 sq on each slope. 1/2" drywall weight about 1lb so total about 300 lbs not 3000.

The drywall weight will be held by the 2x6's still that means there is half the amount of drywall that was there for the last 20 years. All the drywall just hanging right from the main beams, now it will be on the slope, much better support. No weight on the beams. Remember the sagging is caused by long pass water damage.
In summary there is much less weight on main beams and attic structure now. The structure has been significantly beefed up due to the 2x6 added support.

btw, what you know about declaring this place a heritage building? I have a feeling it could be due to the cord wood.

nealtw

The flat ceiling was collar ties and should not have been removed.
http://www.managemylife.com/mmh/questions/112690-collar-ties

bryce

The collar ties are just fine thanks:

The are we are talking about is in the far left bottom of this picture.

bryce

I think hardboard would be a good solution light weight. But drywall would be fine too a bit hard to install.

nealtw

Well the final decision is yours.