Hollow Building Blocks

HOLLOW BUILDING BLOCKS. By L. W. Denison, Mason City. Our first knowledge of the hollow building blocks comes from a man by the name of Drake of Chicago, who, about 25 years ago, spent his whole fortune making and trying to introduce them. The people at that time were well satisfied with common bricks, and would not look into the philosophy of the hollow block, and therefore Mr. Drake failed, though at present time millions of them are used in Chicago. Our first attempt at the manufacture of hollow bricks was in 1895, when the Baptist church of this city was erected. A hollow brick manufactured in St. Paul, Minn., was specified for lining all exterior walls. Feeling confident that we could make these brick and save them money, the building committee changed the specifications, and we secured the contract for these hollow bricks, and at once began to turn them out. These brick were common brick, size 2 ¼x4x8 in., with a 3/4x3 in. air space. The parties were very much pleased with them, as the walls showed no frost, though plastered in January and February, but we were not as pleased with the manufacture of them for these reasons. We could not turn them out as fast as we could our common brick. When put on the car for the drier, if the car was bumped against another car in the drier, the bricks would collapse, and again there were many broken in handling after they were burned, and all around there was quite a loss.

Seeing the faults of these small hollow bricks, we began the manufacture of the large hollow blocks. We at first made a block 8x8x12 in., but found that they were so unhandy in laying that the bricklayer must lay down his trowel and use both hands to get them in place, and so we finally abandoned this size and made a 4x8x12 in., which we found to be a success, as it could be handles by the bricklayer without laying down his trowel. With this size – 4x8x12 in. – we also make a 4x8x10 in., which breaks joints, and a 4x4x8 in., which closes all jambs and corners, these sizes making an 8-in. wall. We also make a 4x4x12 in. and a 4x4x10 in., which, with the other bricks for an 8-in. wall, make a 12-in. wall, bonding every course, both lengthwise and crosswise. These hollow blocks are all figured down to a basis of our common brick 2 1/4x4x8 in. They have many advantages over common brick. The air space makes a dry, frost-proof wall. The plaster is applied direct to the bricks, thus cutting off all expense of lathing. They take on-third less mortar than common brick. In a 12-in. wall we have three separate air spaces as a non-conductor of heat and cold. The hollow bricks at common brick measure are much lighter, weighing only 2.63 lbs., while our common brick weigh 4 ½ lbs., thus they have advantage over common brick in freight, hauling, handling and hoisting to place in the building.

Fifty per cent more wall can be laid per day of hollow brick than of common brick. At the first use of them here the bricklayers objected to them on the ground that they made less days’ work on the building for the bricklayer. They have since found that there are more brick buildings built on account of the lessening cost to the owner, and consequently more days’ work for the bricklayer, and bricklayers are now advising the use of hollow blocks. By means of the hollow block we are able to compete with stone, which is so abundant in this locality. Good limestone, with good beds, suitable for a rubble wall, can be bought for $3.00 per cord delivered at the building in this city. Common solid brick cannot be laid in walls to compete with stone at this price in our city, but with the hollow blocks we can compete, on account of the less space required for the brick walls, and no furring or lathing being required on the hollow blocks. We have shipped these blocks to Dakota, Minnesota, Wisconsin and many towns in northern Iowa, each year shipping more than the year before, and also a greater distance, and I am sure that there never will be a limit to their use. (Brick and Clay Record, Windsor & Kenfield Publishing Company, February 1900, Volume XII, Number 2, Page 86)