The Burtpinc—Its Sanitary Fittings And (Part 6)
Lead of soil-pipes should weigh not less than 8 lb. per square foot of surface. Copper tubing should be “solid drawn” and for sanitation purposes is dealt with by B.S. 659. Cast-iron soil, waste and ventilating pipes should be of medium or heavy section to stand the caulking of joints. The minimum weights allowed are: for pipes 3 in. diameter, 304 lb. per 5 feet length; for 3½ in., 36 lb.; and for 4 in., 40 lb. Cast-iron rainwater pipes can be lighter since they do not need caulked joints.
<Callout type="important" title="Pipe Weight Standards">Ensure soil-pipes meet weight standards to prevent damage from building settlement.</Callout>
All cast-iron pipes should be protected against corrosion by the Angus Smith process or galvanising. Soil-pipe diameters are fixed by local by-laws, with a minimum of 3 inches prescribed by Model By-laws and London County Council.
Lead soil-pipes should have wiped soldered joints; caulked lead joints for cast-iron pipes. Copper soil-pipes usually have bronze welded joints. Waste and overflow pipes should be “middling” weight as opposed to the “strong” pipes used for water services, with a diameter not less than 1½ inch.
<Callout type="risk" title="Joint Failure">Avoid lead joints on iron waste pipes due to thermal expansion issues.</Callout>
Expansion joints are sometimes used in non-rigid conditions. Iron rainwater pipes are fixed by lugs or ears, while soil-pipes use tacks or straps. Proper access caps should be provided for inspection and cleaning of main wastes or soil-pipe systems.
The upper end of a soil-pipe should be carried up 3 feet above the head of any windows or skylights within 15 feet laterally to prevent down-draughts conveying smells into rooms. The foot of rainwater pipes can discharge directly into drains used exclusively for rainwater, but if mixed with foul wastes, they must terminate in a trapped gully.
<Callout type="gear" title="Pipe Fixing Tools">Use straps or lugs to fix iron rainwater pipes and tacks or straps for soil-pipes.</Callout>
Key Takeaways
- Soil-pipe weights should meet minimum standards to prevent damage from building settlement.
- Use wiped soldered joints for lead soil-pipes and caulked lead joints for cast-iron pipes.
- Proper access caps are essential for inspection and cleaning of main waste or soil-pipe systems.
Practical Tips
- Ensure copper tubing is solid drawn to meet sanitation standards as per B.S. 659.
- Use expansion joints in non-rigid conditions to accommodate pipe movement.
- Fix iron rainwater pipes with lugs or ears for stability and ease of painting.
Warnings & Risks
- Avoid using lead joints on iron waste pipes due to thermal expansion issues.
- Do not discharge waste water directly over a rainwater hopper head as it can cause unpleasant odors.
Modern Application
While the materials and standards described here are outdated, understanding historical plumbing practices is crucial for maintaining older buildings. Modern equivalents exist but require knowledge of traditional methods to ensure proper installation and maintenance.
Frequently Asked Questions
Q: What are the minimum weight requirements for cast-iron soil-pipes?
Cast-iron soil-pipes should be medium or heavy section, with minimum weights allowed as: for pipes 3 inches in diameter, 304 lb. per 5 feet length; for 3½ inches diameter, 36 lb.; and for 4 inches diameter, 40 lb.
Q: Why should lead joints not be used on iron waste pipes?
Lead is unsuitable for jointing iron waste pipes due to different coefficients of expansion between the materials, causing weakening of the joint with temperature fluctuations.
Q: How high should a soil-pipe extend above windows or skylights?
The upper end of a soil-pipe should be carried up 3 feet above the head of any windows or skylights if they are within 15 feet laterally to prevent down-draughts conveying smells into rooms.