The sled could have been further assisted in its movement by using wooden rollers. A scene in the 12th tomb of Djehutyhotep shows 172 men pulling a sled carrying an alabaster statue which probably weighed about 60 tons. Water or some other liquid is being poured on the ground to provide less friction. An experiment by the French archaeologist Henri Chevrier showed that a wet compacted earth surface, and the use of a sledge, meant that a block weighing 6 tons could easily be dragged by just six men. The next problem was to raise the stone into position, and ensure the internal cohesion and regularity of the outer form.
All pyramids appear to have been built with internal casing, a series of inclined baulks.
As construction progressed, less and less stone was needed to be put into place, so that 4 per cent of stone in a pyramid takes up the uppermost third of the construction. The Egyptian used ramps composed of brick and earth to assist in the raising of stone. Remains of mudbrick ramps survive at the base of the first Pylon at Karnak, and there are the remains of ramps at Meidum, in the unfinished mortuary temple of Menkaure and near the pyramid of Amenemhet I at Lisht. Dows Dunham has proposed that a mudbrick ramp began at the corner of each face and continued upward around each face forming a helicoidal ramp. However, this does not seem to correspond to the observable ramps.