This section is from the book "Modern Plumbing Illustrated", by R. M. Starbuck. Also available from Amazon: Modern Plumbing Illustrated.

Unless designated in such a sketch, the estimating of fittings must generally depend upon the picture of the work, at different points, which the estimator holds in his mind. While this method often results in the omission of fittings, the practical estimator can generally, if careful, figure very close to the fittings needed. At the same time, very few plumbing systems are estimated which do not call for a considerably greater number of fittings when the work is actually constructed than was estimated. These extra fittings are largely bends and offsets used in getting around obstructions which did not appear from the plans or were unnoticed by the estimator. Allowance should be made for extra fittings and extra material of other kinds. Many practical men claim that the extra stock demanded, over and above that figured in the estimate, will average about 5%.

The fittings should be arranged according to size and character, as seen in the estimate form shown. Before leaving this part of the work, other materials, such as cleanouts, hangers, clamps, roof flanges, oakum, caulking lead, and gasoline should be estimated.

The estimating of caulking lead is an approximation, but experience will enable the estimator to come very close to the true amount. This item is very generally estimated offhand, which often comes wide of the mark.

On large work, especially, a definite estimate should be made, the following being a reliable method. It is clearly seen that no caulked joint will be called for excepting where there is a hub. Therefore, estimate one hub for each length of pipe, the number of lengths being found by dividing the total lengths of soil pipe by 5. In the case of fittings, such as bends, count one hub, tees and Ys two hubs, and double fittings three or more hubs, as the case may be.

In the case of a 4 X 2 Y, one hub would be 4 in. and the other 2 in. The number of hubs of each size should be added, and the amounts multiplied by the weight of lead for the respective size of joint.

The amount of lead used for the several sizes of caulked joints is not a definite amount, as different workmen will naturally use different amounts. The following table shows weights of lead joints:

2-in. lead joiunt ........................ | ......... 1 1/2 lbs. |

3-in. " " ...... | ......... 2 1/2 " |

4-in. " " ...... | ......... 3 " |

5-in. " " ...... | ......... 3 3/4 " |

6-in. " " ...... | ......... 4 1/2 " |

7-in. " " ...... | ......... 5 1/4 " |

8-in. " " ..... | ......... 6 |

10-in. " " ...... | ......... 7 1/2 " |

These weights represent 3/4 lb. for each inch in size of the pipe. Many will claim that 1 lb. to the inch is not too much to figure on.

The weights of lead found necessary for the different sizes of pipe, added together, will give the total amount of caulking lead required.

Oakum is generally estimated offhand. The following table will give an idea, however, of the amount of oakum necessary for joints of different sizes:

2-in. lead joint. .. . | ..... 3 ft. oakum |

3-in. " " .... | .....4/2 " " |

4-in. " " .... | ..... 5 " " |

5-m. ----- | .....6 1/2 " " |

6-in. " " .... | ..... 7 1/2 " " |

7-in. " " .... | ..... 8 1/2 u |

8-in. " u .... | ..... 9 1/2 " " |

10-in. " " . . . . | .....12 |

Such fittings as cleanouts, plugs, and ferrules do not have to be taken into account in estimating caulking lead and oakum, for the hubs into which these fittings are caulked have already been counted.

In the estimating of lead waste and vent pipe it is simply a matter of figuring mentally the amount of each size needed; and knowing the number of pounds per foot of the various sizes, the total weight may be found. It is necessary to know the total weight of both waste, vent, and supply pipe if of lead, as this material is sold by the pound and not by the foot. In filling out the estimate sheet, however, the estimator should be careful to fill out against each size the amount of that size necessary, as when it comes to ordering stock the number of feet of each size will need to be known.

A table of weights of lead pipe is necessary to figure this item from. The following is a table of safe weights for ordinary work:

Diameter of Lead Supply Pipe | Weight per foot |

3/8 in.................... | 1 1/2 lbs. |

1/2 ".................... | 2 |

5/8 ".................... | 2 1/2 " |

3/4 ................... | 3 " |

I ".................... | 4 " |

Diameter of Lead Waste Pipe | Weight per foot |

I in.................... | 2 lbs. |

1 1/4.................... | 2 1/2 " |

1 1/2".................... | 3 1/2 " |

2 ".................... | 4 " |

4 ".................... | 6 " |

In connection with lead pipe, wiping solder should also be figured. The number of joints of each size may be quickly estimated, and knowing the amount of solder necessary for a joint of each size, the total weight of solder may easily be found. It is very customary for plumbers to estimate solder according to fixtures - so much for a sink, so much for a water closet, etc. In figuring many plumbing systems this would be safe if the estimator has a correct idea of the amount necessary for each fixture. In work which is out of the ordinary run, however, it might not be safe to estimate in this way.

In getting at the full amount of solder, lead supply-pipe joints and connections, flush and supply-pipe joints for water closets, for urinals, slop sinks, etc., must be taken into account.

The amount of solder used per joint of the different sizes is a variable quantity, as some workmen make much heavier joints than others. It is customary among some estimators to allow one pound of solder per joint, regardless of size, including the small supply-pipe joints, as well as the large-size waste and vent-pipe joints. This might possibly have averaged safely in the days of lead supply work, but as work is now generally constructed, a better way would seem to be to find by practice the weights of joints of the several sizes, and thus make the estimate a close and accurate one. The following table may be used as a guide, though undoubtedly varying widely from the custom of many workmen:

Diameter of Pipe. Solder per Joint .... | 1/2 in. 3/4 in. | 5/8 in. 1 lb. | 3/4 in. 1 lb. | 1 in. 1 1/4 lbs. | 1 1/4 in. 1 1/2 lbs. | 1 1/2 in. 1 3/4 lbs. | 2 in. 2-2 2/4 lbs. | 4 in. 3-4 lbs. |

In the matter of galvanized piping, the number of feet of each size should be estimated.

To find the amount of galvanized supply pipe, brass or lead, as the case may be, reference must be made to the cellar and floor plans mostly in figuring out horizontal runs, and the elevation referred to, to give vertical measurements. The matter of fittings on supply work is a difficult matter to estimate in detail, as they are numerous, and it is hardly possible to figure on just what fittings and the respective amounts of each that are going to be required. On such items as these the estimator of experience will often cast up the amount in his own mind after a little study of the plans, and he may usually come very close to the amount of cost represented in the item.

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