I am about to do a loft conversion the inner purlins are not the same distance from the ridge and one is lower than the other this will cause a problem with head height .The purlins are also in three sections each one about 12 feet in length and propped on the joints.I would like to change them while the tiles are off the roof . The joints on the new purlins will be moved to new locations over internal walls the maximum span will be 17 feet which is the best type of beam to use steel/wood or glulam
Thanks
Thanks