FARM BUILDINGS

New Zealand Tablet, Volume LII, Issue 10, 18 March 1925, Page 53

FARM BUILDINGS

(Contributed.) CONCRETE FLOORS ON THE FARM. (Continued.) Placing. Sufficient help should be provided to mix and convey the prepared concrete to its destination as fast as the leveller or placer (on large jobs there may be two) can deal with it. Delays in this particular allow time for the finer portion of the concrete —which is essential to make a good surface finishto run back to a lower level. The ground base should also be well saturated with water before commencing operations, and as the work proceeds (if necessary) in order that it may take up or absorb nothing of the finer mixed concrete. The placer should have a trowel, float, shovel, and straight-edge of suitable length ready at hand. The most convenient end to work from having been chosen, care should be exercised to rake back the coarser shingle from the screeds and tamp down the concrete at the edges of the prospective floor. What adheres to the wheelbarrow after each successive dumping may be readily scraped out by means of the steel float. The concrete should be allowed to heap up an inch or two above the level of the guiding screeds, then after each successive couple of wheelbarrows have been tipped apply the straight edge as quickly as possible, and "level off" working it to and fro with a short-stroke sawing motion, advancing slowly at each stroke. Note here, and this is important, that the levelling off be done as soon as possible after each quota of concrete is placed in the rough, and the coarser shingle raked forward; in order that the finer material which is essential to smooth finish may be, as it were, caught on the surface. The consistency of the prepared concrete should be such as to permit of the fairly easy working of the straight-edge. After each 'levelling off," if the straight-edge be rested on its edge across the screeds, it will shield the finished work from splash when emptying the wheelbarrow, and save labor—a splashed surface involving re-levelling. The necessity of keeping the base of the floor-to-be-concreted will now be apparent

a dry ground would absorb a considerable amount of the moisture from the concrete. As soon as a yard or so has been levelled right aross the floor, the surface should be dusted lightly over with dry cement, and very lightly "floated off," while it is still moist. •

This cement-dusting must not; however, be overdone. What suffices to assist in forming a surface finishthe rougher spots being treated a little more liberally will indicate the quantity.

Heavy cement dusting is apt to induce surface cracking some time after the setting. The object in doing the dusting, yard by yard, as the placing and levelling of the con= crete progresses, is to seize the opportunity of being able to reach over the finished work without taking any chances of causing any depressions on its surface, and at the same time to thoroughly spread the cement that it may be properly assimilated while the con* crete is still wet and plastic.

Lifting the Centre Screed.As soon as we have completed the laying down of the whole floor (18 x 36) we must pull up the dividing screed between the two sections composing* the same.

This screed was put down solely for convenience in laying down and levelling off the floor, and it is important that it be lifted and the space which it has occupied be filled in while the concrete is still in the plastic state. To do this, first lay down a board 9in x lin or 6in x lin) on each side of the screed about an inch clear of it on one side and just clear of the supporting pegs on the other, then stand over it, placing a foot on the boards on either side, and by the aid of a pick "prise" up one end and take it out as carefully as possible. Fill up the channel or rift resulting from the displacement of the screed with concrete, level off with a short straight edge and finish with the float, lifting or moving back the boards as the work progresses. (To be concluded.)