PISÉ HAND RAMMERS
The hand-rammers are undoubtedly worth study and careful design. A set of three seems to meet all ordinary requirements, and those shown on p. 101 may be taken as typical. They should be of hard-wood, smoothly finished, and provided with long handles. They should be 9 in. to 12 in. long, and about 5 in. by 4 in. at maximum cross section.
In the sketch they are shown “narrow-ways-on.” No. 1 is used for preliminary pounding and final finishing, No. 2 for general consolidating, and No. 3 for working along the edges, against window stops, and under cross-ties.
A South African correspondent, Major Baylay, makes interesting comment as regards rammers and local pisé practice:
South Africa
“My experience of all black labour is, that they won’t put any ‘guts’ into it. They therefore want fairly heavy rammers, which they can lift and drop, say a foot, and which will do the rest for them. The heat of the sun and extreme dryness of atmosphere out here make it advisable to cover up completed courses at once with sacking, moist for choice, otherwise it is liable to dry out too quickly and crack. It dries out uncovered at night very well, when there is no rain.
“The red loams of South Africa, where not too sandy, make excellent pisé. They or their equivalent are found almost everywhere. In the dry state they set so hard that moisture added just before ramming is useless. A large heap must be made, well damped and covered over with moist sacking, and left until the moisture is distributed throughout the mass. When about four or five days old, in ordinary weather, the earth is ready to use—viz., just wet enough to bind when gripped in the hand. It should be passed through a sieve. I use a sort of ‘chicken run,’ 8 ft. long, and throw the earth on to it before using. Six feet of it is ½-in. mesh, and 2 ft. ¼-in. mesh; the reason for this is that, if the earth is a little too dry, it does not always bind well with the previous layer. Therefore, put a few petrol tins of the fine earth into the shuttering first in order to ensure good bond, and throw the coarser stuff in after.”
Second Note by Major Baylay, Peter Maritzburg, Natal, South Africa
“I have completed a small building, and though weather conditions have been as bad as possible, it is sound and very satisfactory.