Work procedure for rubble stone masonry work
- Rubble must be as per specification. It must be hard, durable and tough. The stones must be soaked before use. It must be roughly dressed and uniformly colored and of pretty equal size.
- There should not be hallow space inside the wall.
- The masonry work will be carried out as far as possible at one uniform level throughout, but where breaks are unavoidable the joint will be make in good long steps so as to prevent cracks between old and new work.
- Through stones must be staggered at regular intervals.
- The stones must be arranged to break joints as much as possible and long vertical lines must be avoided in face work
- Through stones ( headers) should be used in successive layers at 1.00 m (3’ to 5’) to 1.5 m apart both ways.
- Use artificial header ( R.C.C) in case of more widths
- Care should be taken to secure a good mortar bond throughout the masonry. ( approx. 20 mm i.e. 3/4” )
- Corner stones are prepared from mason’s hammer.
- The joints should not be too smooth to avoid sliding actions in stones.
- The wall should be truly vertical i.e. in plumb.
- Minimum 12 mm (1/2”) margin should be provided in columns external face and masonry to avoid the offset of rubble in plinth masonry after plaster.
- Old work should be cleaned and watered before starting of new work on it.
- Keep expansion joints at 15 m interval, in case of compound wall.
- Lay some vertical stones in masonry for better bonding of 1st and 2nd day’s work/layer of rubble masonry.
- The curing for masonry should be done for minimum 2 weeks.
- The through stones should have the length at least thrice the depth.
- The joints should be pointed after proper curing and racking for at least 25 mm (1”) depth
- Spauls are to be used wherever necessary to avoid thick mortar beds for joints and shall not exceed 20 per cent
- The use of wooden mallet must be carried out to hammer down stone in the position and solidly bedded in the mortar
- Iron templates are to be used to compact the mortar in joints
