Page:The Building News and Engineering Journal, Volume 22, 1872.djvu/291

 i +, Peo, THEYBUPDDING NEWS. 5, 1872. THE BUILDING NEWS. 273 to be soldered on for top sheets, just as men- tioned above for others. The other side of roof being also laid in a similar manner, and the wooden rolls all fixed on between the sheets, as per Fig. 56, the zine roll-caps (which I may here mention are generally machine-made) are then slid down over them, as per M, Fig. 57. But as these zine roll-caps are generally in_8ft. lengths, while the side SE roof is 15ft. deep, it follows that there must be a joint in each stretch of roll-capping, which joint is simply - made by slipping the upper roll-cap an inch or two over the lower one, and also soldering it. One nail or small catch put in under joint at top of each roll-cap is sufficient to hold roll-cap in its place, as, if properly put on, the zine roll-cap grasps the roll below it firmly. In order to allow zinc roll-caps to be slid on, a small bit of the wood of ridge may have to be cut out, but if so it does no harm, Where the work is properly done these zine roll-caps fit like a glove, both allowing the zinc underneath them to expand, and at same time holding it. After roll-caps are on the ridge must then be covered. It makes a very neat and trades- manlike job to put on a good lead ridge of sheet lead, which can be nicely worked over all the rolls, and allowed to come down roof several inches, so as to give sufficient overlap. Fig. 6)b. or 7b. about 15in. broad, 58 shows perspective view of roof when finished. In the beautifully got-up and use- ful illustrated pamphlet on ‘ Zine as applied to Roofing Purposes,” issued by Messrs. Braby & Co., it is stated that Mr. H. G. Rein. architect to Canterbury Cathedral, had covered the cloister-roof with zinc, thirty-three years ago, with lead capping, and Tt had stood so well that he in- tended to use it further. This employ- ment of the ‘‘ lead-capping,” therefore, agrees with my recommendation here of lead for ridge. Another way to finish ridge would be one which I ae respectfully call the attention of architects and builders to, as it could easily be adopted and used for roofs which are covered with slates, to the great saving of the slates from breakages from the feet of sweeps or other parties who have occasion to walk along top of roof. Fig. 59 shows common sige of ridge, the centre- piece projecting up about 3in. or so above sides. In this case the wood being only about 1}in. or 2in. broad, and also round at top, parties walking along cannot very well walk on top of ridge, as at O, and so the feet are put down on each side, as at P P, thus perpetually causing the slates to be broken there. Now, if top of ridge at O were more flattened, aad also two strips of wood, about lin. thick and about 3in. deep, were taken and nailed on, one on each side ae as per QQ, Fig. 60, then arties having occasion to be on roof could easily walk along top of ridge R without requiring to touch slates at all. To cover this form of ridge where slates are used, the zinc may be put on as per Fig. 61, the dotted line being galvanised iron straps, put on every 2ft. Gin. orso. Or, another plan would be to put on aflashing—either lead or zinc—on each side, and a separate piece for top, as per Fig. 62. Or, again, if we turn to Figs. 18 and 19, p- 199, the hook and eye system there depicted —designated, ‘ Fox's Patent Underlock Fastening, ” but which patent is now held by Messrs. Treggon, Hickson, & Co.—may be used ; the hooks being driven into each side of ridge where the nails SS Fi ig. 61 are shown, and the eyes soldered on to. inside of zinc of ridge, Cae ridge ; or vice versa as shown at Figs. 18 and 19. It will be observed that the tops of ridges and at R, Fig. 60, are not flat, but that they are slightly convex, the rise in centre in actual size of ridge being Figs. 61 and 62, fully Hin.; or, in other words, the top of the form of ridge I am referring to is ap are of a circle 14in, in diameter, of - which the chord is 4in, The shape and style of rolls given in this and in the former article are, I perceive, not included in the pamphlet ‘“« Zinc as applied to Roofing Purposes,” issued under the aus- pices of the architects and engineers to the London manufacturing agents “of the Vieille Montagne Zine Co.; but as I not only highly approve of it inyself, but it also has a fine appearance and makes a good job, I could not do otherwise than show it as I have done, more especially, too, as it has for some time back been largely used. The style of overlapping the zine on top of rolls eae Fic.74- Fia.73 aie i leet ae Se ae FUR fol Y Ky | espe aiaen Ae w ers" Ww ye __“.— by dotted lines, Fig. 37, p. 212 (I may here observe that as engraved at W, Fig. 37, the zine roll-cap is shown as if it stood apart from roll underneath it: but, in fact, it ae upon it, and should therefore have been shown closer to it) is the maximum for setting up sides of sheet: butin thousands of cases, and unless the customer wishes it otherwise, the zinc at sides of sheets needs only to be set up about half way up each side of all as shown by Figs. 50 and 56 above. This is es- pecially the case where there is a good slope, and no danger from half-melted snow lying. Messrs. J. & R. Fisher, the architects of the Zine Co. above referred to, in a note to me, recommend the style of roll shown by Fig. 63, which is certainly very plain, and mh I will admit may, perhaps, be a little cheaper at first cost and easier to put on than the style at Fig. 50; but I can hardly admit that : either enaken a better job or looks so well. However, where there are many men there are many minds, so there is plenty of scope for both plans. Fig. 63 is known as the “ French Plan,” and if there be no objections, Fig. 50 might be called the British Plan. Another plan of roll is that shown by Fig. 64, with fine zinc clips 2in. broad, in the length of sheet put under wood roll and turned down as shown. ‘This appears to me to be an improvement upon Fig. 63, but to my mind it could be greatly improved vy being rounded at top and also contracted a little more at bottom, which would enable zine roll- cap to take a firmer hold of roll, and also PIONS WOOK WW eal 4 Fac. Hi Flaws suit the purpose better. The style of Fig. 63 also requires zinc clips put under wood- rolls, as shown in Fig. 64; none such are re- quired for Fig. 50, as the "sty le of wood-roll renders them 1 unnecessary. The style of roll and shape of roll-cap at Fig. 50 are also un- favourable to capillary attraction having scope. Fig. 65 shows ‘ Patent wood- roll with zinc drawn over by machinery.” It is Yin. high, and 23in. broad. I cannot say that I consider this style any improvement upon Fig. 64; it is, however, a variety. In Fig. 65 L would be afraid of snow or heavy rain being blown in at sides of roll, and so rotting the w wood, especially where the roof was very flat. In*the foregoing styles of laying zine it will be understood that the roofs under zinc are boarded—~. e., that the zine lies on boards. In what is known as ‘ Italian corrugation,” no boards are used, wooden rolls 3in. deep, by 1$in. broad, being put in every 1ft. 3in., centre to centre, and ‘purlins fixed every 10ft. or so. The overlap at top and bottom of sheets is about 4in., and the serew-nail ought not to be put in through both sheets. Fig. 66 is section of this style. The fold in Fig. 67 is an improyement upon the mere overlaps