Hi guys, Got a bit of a silly question

I've been working on some custom segments, but every time i get them into fpsc the roof is always out of alinement to the walls (see pic below)The walls line up perfectly with stock roof segments but for the life of me, I can't get them to work with my custom roofing.
Heres what I get as segments.
Here's how it should look (roof as entity)
script used
;Segment Spec
;Header
partmax = 0
lastmeshmax = 0
;Segment Parts
partmode0 = 0
meshname0 = meshbank\-HoriZon-\Aliens roof.x
offx0 = 0
offy0 = -51
offz0 = 0
rotx0 = 0
roty0 = 0
rotz0 = 0
texture0 = texturebank\-HoriZon-\Aliens roof.dds
transparency0 = 0
effect0 =
colmode0 = 0
csgmesh0 =
csgmode0 = 0
csgimmune0 = 0
lightmode0 = 0
multimeshmode0 = 0
materialindex0 = 0
;Segment Visibility
visoverlay = 1
visfloor = -1
visroof = -1
viswallb = -1
viswallr = -1
viswallf = -1
viswalll = -1
viscornertl = -1
viscornertr = -1
viscornerbr = -1
viscornerbl = -1
;Segment Blueprint
mode = 1
symbol = 0
floorsizey = 1
sidesizex = 100
sidesizey = 1
sidesizez = 100
groundmode = 0
kindof = 0
;end
My scripting isn't grate but I've played around with the fpi and searched the forums for ages with on luck.
Could someone pleas point out where I'm going wrong with this? Before I pull out what little hair i have left
Thanks
-H-