Just a few notes ref. what can be a difficult and dangerous job. Perhaps others will add their experience and skills?
1. some stacks are difficult to get at, one might req. staging to bridge extensions, conservatories or fences etc.
2. try to work off a Zip-up tower or scaffold for safety.
make sure that your access eqpt will fit and not snag pipework, fences or overhangs.
3. tie-in the tower to the brickwork and use stabilisers.
4. work out exactly what and how you are going to do before starting the job.
5. have all materials on site before starting - that means all, one can't deprive a household of its waste and drainage for more than a working day. eg. prepare everything the day before and start work first thing the next morning.
6. usually, one now uses push-fit or solvent -weld 110mm plastic pipe and fittings.
7. determine if the new stack is going in a new position or the same location.
8. determine if the closet bend from the existing WC is being replaced ( they are often in lead) and if the wastes from bath and basin etc are to be replaced or re-sited. These options could lead to inside work and disturbance at the WC spigot and under the bath and brickwork repairs to the exterior elevation.
9. determine if the old stack is firmly "clipped" to the wall and is not perished at the top vent portion. If its not stable then one must tie it in like the access eqpt. Dont attempt to work on an unstable stack until it has been made secure.
10. start cutting from the top of the stack, small sections at a time, use a 9" angle grinder, one person to cut and one person to hold the piece being cut is ideal.Never attempt to topple the stack as in"Timber" there she goes. 11.Before cutting one can make a small opening at the base of the stack and stuff it with paper to prevent debris from blocking the slow bend. However, dont weaken the stack by cutting too large an opening.
12. lower all off cuts on a rope dont throw them down or you might destabilise the stack and /or the tower.
13. Breaking into the main drain or sewer is another story that others have talked about, but often one can tie-in to a CI stub at ground level or below ground. Use a no-hub/Fernco fitting or similar custom fitting.
14. determine your centre line, mark it and set your clips use lots of clips esp. above and below any Tee's.Determine the position of the WC tee.
15. typically, strap-on bosses are used for the wastes - convenient for falls and cheaper than using tee's.
16. picking up the WC spigot thro the wall: some people work from the stack tee branch to the closet bend thro the wall and others work back from the WC spigot to the tee branch. As long as the setting out is accurate and the fall is shallow either way will work. It's useful to have someone in the bathroom determining centres and heights while the other person is on the scaff outside.
Cutting into a Cast Iron soil stack:
1. much of the above 16 points applies esp. the safety issues.
2. first determine if the stack above the cutting in position, typically at the base of the stack for a second WC tee-in, is firmly clipped and the stack is not perished or wobbly.
3. personally, i wouldn't attempt cutting in at the base of a stack given that at some stage of the proceedings you will have one ton of iron suspended on the original fixings and temporary propping.
4.cutting out at just below the bathroom WC tee and dropping the upper vent portion of the stack and the branch running to the WC is often done.
5. make sure that the lower stack is secure and use fernco or similar transition fitting CIxplastic to tie in the new 110mm plastic pipework and fittings above the transition point.
6. again start at the top of the stack and work slowly down constantly checking the stability of the stack.
Re-reading this post i see a number of areas which could do with enlarging, i haven't got time but perhaps others will fill in, criticise or hopefully,show better.
1. some stacks are difficult to get at, one might req. staging to bridge extensions, conservatories or fences etc.
2. try to work off a Zip-up tower or scaffold for safety.
make sure that your access eqpt will fit and not snag pipework, fences or overhangs.
3. tie-in the tower to the brickwork and use stabilisers.
4. work out exactly what and how you are going to do before starting the job.
5. have all materials on site before starting - that means all, one can't deprive a household of its waste and drainage for more than a working day. eg. prepare everything the day before and start work first thing the next morning.
6. usually, one now uses push-fit or solvent -weld 110mm plastic pipe and fittings.
7. determine if the new stack is going in a new position or the same location.
8. determine if the closet bend from the existing WC is being replaced ( they are often in lead) and if the wastes from bath and basin etc are to be replaced or re-sited. These options could lead to inside work and disturbance at the WC spigot and under the bath and brickwork repairs to the exterior elevation.
9. determine if the old stack is firmly "clipped" to the wall and is not perished at the top vent portion. If its not stable then one must tie it in like the access eqpt. Dont attempt to work on an unstable stack until it has been made secure.
10. start cutting from the top of the stack, small sections at a time, use a 9" angle grinder, one person to cut and one person to hold the piece being cut is ideal.Never attempt to topple the stack as in"Timber" there she goes. 11.Before cutting one can make a small opening at the base of the stack and stuff it with paper to prevent debris from blocking the slow bend. However, dont weaken the stack by cutting too large an opening.
12. lower all off cuts on a rope dont throw them down or you might destabilise the stack and /or the tower.
13. Breaking into the main drain or sewer is another story that others have talked about, but often one can tie-in to a CI stub at ground level or below ground. Use a no-hub/Fernco fitting or similar custom fitting.
14. determine your centre line, mark it and set your clips use lots of clips esp. above and below any Tee's.Determine the position of the WC tee.
15. typically, strap-on bosses are used for the wastes - convenient for falls and cheaper than using tee's.
16. picking up the WC spigot thro the wall: some people work from the stack tee branch to the closet bend thro the wall and others work back from the WC spigot to the tee branch. As long as the setting out is accurate and the fall is shallow either way will work. It's useful to have someone in the bathroom determining centres and heights while the other person is on the scaff outside.
Cutting into a Cast Iron soil stack:
1. much of the above 16 points applies esp. the safety issues.
2. first determine if the stack above the cutting in position, typically at the base of the stack for a second WC tee-in, is firmly clipped and the stack is not perished or wobbly.
3. personally, i wouldn't attempt cutting in at the base of a stack given that at some stage of the proceedings you will have one ton of iron suspended on the original fixings and temporary propping.
4.cutting out at just below the bathroom WC tee and dropping the upper vent portion of the stack and the branch running to the WC is often done.
5. make sure that the lower stack is secure and use fernco or similar transition fitting CIxplastic to tie in the new 110mm plastic pipework and fittings above the transition point.
6. again start at the top of the stack and work slowly down constantly checking the stability of the stack.
Re-reading this post i see a number of areas which could do with enlarging, i haven't got time but perhaps others will fill in, criticise or hopefully,show better.
