Just hung drywall in new attic living space and have a spot where gap is too big to use mud . Area is where knee wall and sloped part of wall meet and also meet with another wall at 90 degrees. (corner)
Shimmmed and straightened walls but unfortunately missed this corner. Have about a 5/8 gap where angled part meets kneewall.Looks like that end rafter is about 1/2 inch higher than the rest. Instead of removing wall at 90 degrees to get to problem piece and shim it out , I was hoping that someone could recommend a good filler that won't shrink and crack.

Thanx in advance

 

Fill with regular drywall mud. If time is a factor use quick set. 20 minute is great. After the mud is dry, like you said it shrinks and cracks, put a strip of drywall tape (mesh or paper) flat on the large gap. then tape as usuall. By flat tape I mean only cover the area you filled. Don't angle the tape. Pre filling is an important part of the finishing process. Look for other gaps as well and pre fill them. Anything over 1/8".

 

Thanx coops. Wasn't sure if it would work. Haven't had to fill gaps that large before and don't want to repair again after room is finished.