When a carpenter has to figure upon painting it is better for him to get some reliable mechanic who is in the business to give figures on the work. Painterfigure their work by the square yard. I have inquired of practical painters concerning their methods of calculation and have failed to find any uniform scale or rule by which to measure surfaces. Nearly all master painters have a basis of calculation, but the accuracy of their estimates depends so much upon personal judgment as to the nature and extent of variations, that their methods would be useless to persons of less accurate judgment. The methods also vary according to the nature of the work and the training of the painter. No two would measure in the same way, perhaps, yet they might reach nearly the same results. Although it is true that very much depends upon the painter's judgment, I will try to give a few hints which will be found in some cases entirely trustworthy and in all helpful. One way of measuring is to obtain the number of square feet in the sides and ends of a building as if they are flat surfaces, give a rough guess as to the dimensions of trimming, etc, and let it go at that. This plan may work well for a good guesser, but for general use it is not very satisfactory. Another way in connection with wooden buildings is to measure the length and exposed surface of one strip of siding, then count the siding and multiply the dimensions of one by the whole number on the side or end of the building ; the product will be the surface measure. This is a better way, but its accuracy depends upon a pretty thorough acquaintance with compound numbers, as dimensions must be reduced to inches, then back to feet or yards, according to the basis of calculation. Trimmings, etc, are measured separately. Common siding are put on with one board overlapping another, and the lapping edge of the board is raised from the perpendicular, so that it presents a diagonal instead of a flat surface ; and there is also the exposed edge of the board, about ½ inch, which should be included in the estimate. Suppose, now, that the exposed portion of a board of siding is 4 inches - the usual width - and the edge ½ inch. It will give the side of a building just 12½ per cent, more surface than it would possess if it were perfectly flat. Hence one-eighth added to the dimensions, obtained by multiplying hight and length together, will give the actual surface measure of common siding.
In drop siding, which is frequently used, there is an exposed edge of about ½ inch, and about ½ inch more surface on the molded edge than there would be if it were flat, thus making a total gain over flat surface of ½ inch on each piece of siding, or 18½ per cent., which is very nearly equal to one-fifth. Hence one-fifth should be added to the dimensions in square feet of a building to obtain the surface measurement for drop siding.
In measuring the gable ends of ordinary buildings the dimensions should be one-half less than actual square measure. For example, if a building is 20 feet wide, and is 10 feet from the level of the frame plates to the point of the roof, multiply half the width, 10 feet, by the hight, 10 feet, and we have 100 feet surface of the gable end, to which should be added the percentages for the edges of the siding boards, etc. No deduction is usually made for openings. Cornice and trimmings should be measured separately. If there are panels, beads and other projecting and receding features, brackets, etc, carefully measure one of each, count the number on the building and multiply by that number; the product will be the total surface. Open brackets on cornices and scroll and lattice work on verandas should be measured solid, as the edges fully make up for open spaces.
The utter lack of uniformity in house trimmings compels more or less reliance upon the judgment of the painter in measuring them. I can suggest no rule for measuring which can be used with satisfactory results in all cases. What would be admirably suited to one would be wholly unadapted to another, simply because the architectural features are unlike. Here there is no alternative but to exercise judgment in considering these important features.
In calculating the quantity of paint required upon the basis of surface measurement, from 12 to 40 per cent, should be allowed for trimmings, etc, according to their size and shape. For plain work 12 to 20 per cent, will be found a fair average. This depends, however, upon the number of doors and windows, style of frames, etc. On Queen Anne structures, which are painted with two or three body colors and are burdened with numerous and elaborate trimmings, calculations must be made of the portions of the buildings to which the different body colors are to be applied either by divisions of total measurement or by separate measurements and the trimmings considered separately. As outside painting on buildings usually consists of two coats over a previously painted surface, or if on a surface never before painted, preceded by a primary coat, it is customary to estimate the quantity of paint required for two coats. Surfaces are so variable in condition that no rule can be given which will be found applicable to all cases. The quantity of paint required for two-coat work varies from 3½ to 5 gallons per 100 square yards, and I would by all means advise carpenters to obtain figures from experienced painters in this particular line of business. hardware. Estimating hardware is as much of a necessity with the carpenter as estimating lumber, but it is not attended with as many variations and difficulties. The number of fixtures for door and window trimmings, etc, may be readily counted from the plans, and it is only through the omission of some items that any serious mistake is likely to happen. A careful study of the plans and a well prepared list of hardware items from which to figure is a guard against mistakes from omissions and a guide to cor rect estimating.