ROAD SEALING

Dominion, Volume 20, Issue 49, 22 November 1926, Page 8

ROAD SEALING

SCHEME FOR SECONDARY STREETS

EXPECTED TO PROVE REAL ECONOMY HOPE FOR THE FUTURE Now that the public have become accustomed to the great benefit in many ways due to the paving of the main thoroughfares with bituminous hot-mix, many have naturally thought in what way such benefits can be extended to the residential streets, where day after day through the spring gales the housewives and domestics have to battle with a never-ending swirl of dust, made all the more certain on account of the everincreasing motor traffic, which is the chief disturber of macadamised roads. Residents of Oriental Bay on the main parade front suffered greatly in dry weather from this disability, and speak in glowing terms of the marvellous change that has been wrought in their condition since the parade has been paved. Others who still suffer will probably hail with delight the proposal brought forward at the last meeting of the City Council by Councillor 11. D. Bennett (chairman of the Works Committee) to expend up to £3OOO on the sealing of certain streets that can scarcely' be called main streets, for in the proposal lies thq hope that this experiment will be the forerunner of a more extended scheme of giving a sealed surface to most of the residential streets which could be treated without a great deal of preparation The qualification is necessary at the present juncture, for in some cases the cost of preparation would be as great as the cost of sealing. Those streets which have been named by Mr. Bennett are all in a condition to take the sealing coat with little or no preparation, and the work is estimated to cost somewhere in the vicinity of Is. per square yard. Mr. Bennett states that- the sealing coat mentioned is a preparation of tar and bitumen, applied in two courses, with a finishing dusting of coarse sand or metal grit; is, in reality, an adaptation on a lighter scale of the mixture, which has for some years been used very effectively on some of the roads in the Taranaki district. Already the City Council has experimented with the mixture on the Hataitai Road, and there is also a stretch of road at Taita sealed with the .fame mixture, which has stood up well to the heavy traffic to which it has been subjected. One important feature in connection with the sealing mixture referred to is the necessity for using good tar, which may possibly have to be imported from Newcastle, in New South Wales. The tar turned out in Wellington is not considered rich enough in certain elements to make good in this mixture. With the advent of vertical retorts coal tar is deprived of some important elements which made it such a valuable aid to street works, and care has to be taken to secure the right article in order to ensure a mixture that will stand up to the changes of temperature and give it the wearing quality demanded of it. It is proposed to seal the roads by contract.

Maintenance will depend exactly on the amount of traffic to which the sealed street is subjected. With streets such as Molesworth, Mui grave, and Murphy Streets (to quote three streets' on the list), it is estimated that a painting every three years will suffice to keep the 'surface in order, whilst in the case of streets where the traffic is lighter such paintings (with liquid bitumen) might only be required once every five years. An example of the manner in. which this painting of road surfaces with bitumen can hold up is given in Mercer Street (between Lower Cuba Street and Victoria Street). This road has now been down about five years, and, though it carries very heavy traffic, it has held out up to the present with an occasional patching. Upon the success of the £3OOO venture about to be embarked upon depends to a large extent the future. policy of the council in respect to residential streets; but from all acounts there is reason to believe that the sealing of the streets in the manner proposed is likely to. prove a real economy, as against the rebuilding of such streets with macadam.