Roof rafter help

[David hackett]

Hi

I’m upgrading my roof rafters to accommodate a dormer conversion and I need to install 150x47 c24 timbers with a birdsmouth cut onto the wall plate. A third cut is 49.5 which the timber rafter will be 25mm to tall to the existing roof rafters of 75mm.

how do I loose this height difference so the roof stays the same height??

thanks



Read more: https://www.diynot.com/diy/threads/roof-rafters-help.582434/#ixzz7E5D7LFXF

 

[^woody^]

Using the existing seat cuts as a guide, you'd measure your new rafter depth - 150mm (more like 145mm) perpendicular from the top of the rafter and where this meets the horizontal line of the seat cut is your new rafter seat cut.

It will just be one horizontal cut unless you can drop the rafters in vertically with the tiles and membrane off.