When removing the beams you must take care, as they are made of card and tend to become very flimsy with age. They are held in place with nails so once these are removed they just lift off, unless the nails have rusted which tend to make bigger holes in the card. One of mine split whilst removing the nail from one of the corners. I repaired this with paper parcel tape on both sides of each of the corners to give it extra strength. Also filling the nail holes with PVA glue.