Ashlar Fine Tooled
When building a wall, the ashlar blocks are laid in horizontal courses, or layers. V joints and the wall above with plain ashlar masonry to give the base of the wall an appearance of strength. It is therefore important for the engineer to understand the different finishes to which stone is dressed, but it is not necessary for him to be able to make the templates for each stone.
The problem is that stone masonry is a broad term. You won’t need years of expertise to understand the various construction styles (besides, we’ve got you covered in that department). As with most subjects, a hierarchy of organization exists in stone masonry. Masonry may also be used for the construction of walls. It is the finest type of stone masonry work. Another type is ashlar rough tooled, here the only difference is that bed and sides of each stone block are finely hammered. Identify the type of stone masonry. Bond and the thickness of mortar joint does not exceed 3 mm.
Classification of Stone Masonry| Building Construction This video includes Classification of Stone Masonry such as 1:00 1.Rough dressing and ashlar masonry – Ashlar Fine Tooled Masonry
In this lesson, learn about types of ashlar masonry and its history of use in cultures around the world. There are different types of ashlar masonries. So as to have all sides rectangular. Ashlar is in contrast to rubble masonry, which employs irregularly shaped stones, sometimes minimally worked or selected for similar size, or both.
European masonry the blocks are generally about 35 centimetres (14 in) in height. There are two primary types of stone masonry. Though raw materials are cheaper as a result, the process requires more time to ensure pressure is distributed over the maximum amount of lateral area, while avoiding long vertical joints.
The surface of a stone finished in this way resembles pointed work, but it is not so regular. In this kind of work, the stone is dressed with a point so as to leave continuous groves over the surface. In this kind of work, the lines are continued across the width of the stone to the draft line (when one is used). Machine-drove work, as will be noticed, is more regular than hand drove. The stones may also be finished with their exposed faces tooled to show the texture of the stone. The height of the stones used is never less than their breadth and their length is never less than twice their height.
The bed and the side joints in this type of work should never exceed 3 mm. The thickness of joints in this type of work should never exceed 6 mm. In ______ rubble masonry the stones used are flints which are irregularly shaped nodules of silica. In _______ masonry, the stones of irregular sizes and shapes are used which are arranged so as to have a good appearance. Interested in typesofstonemasonry-130903205204- ? Bookmark typesofstonemasonry-130903205204-. Resistance to weather – solid wall of brick. Students in online learning conditions performed better than those receiving face-to-face instruction. When the proper depth has been reached, the sand blast is stopped and the material used to cover the raised part of the stone is removed.
The finish shown at a, known as scale work is obtained by cutting out rows of shallow flutes between the drafts of the stone with about a 1-inch tool.
The application of this finish to a window jamb is shown at b. The cutting can be done either by hand or by machinery. Whatever may be the quality of mortar used, the wall should contain as much stone and as little mortar as possible, as the former is the stronger material.
The joints in stonework vary in thickness from 3/16 to 1/2 inch. Rubblework consists of stones in which the adjoining sides are not required to be at right angles. Conglomerate and slate stones abound in many localities, and are cheap and durable, but they do not cut easily. The stones are set irregularly in the wall and the interstices are filled with spalls and mortar. Such walls are frequently pointed with colored mortar, showing raised joints. The quoins or corner stones, a are hammer-dressed on top and bottom, and may be either cut stone or rock face. All joints should be hammer-dressed, as shown at b, and no spalls should show on the face, while the mortar joints should not exceed 1/2 to 3/4 inch in thickness.
Walls of this kind are built of small, uncut boulders, and are frequently employed for fences and rustic-house work. In this case, all the top and bottom joints of the rubblework have level beds, as at b. For such walls, the stones are generally roughly dressed before the wall is begun. Coursed rubble, when well built, makes a very solid wall and is extensively used. The latter may therefore be considered as the connecting link between rubble and ashlar stonework. If the work is not done in this manner, ashlar walls will present a poor appearance. When such stones can be obtained readily, this kind of work is not very expensive. The latter may also be brick, as the ashlar can be well bonded into it. In this class or work no attempt is made to have the vertical joints over one another, and it has only general arrangement in courses, as shown.
The next point to be considered is the lengths of the blocks. It generally takes more time to build than broken ashlar than coursed work; hence this kind of wall is more costly, owing to the increased amount of labor required to fit and lay the different sizes of stone.
It is generally laid up as rock-faced work, but in some cases, it is tooled or hammer-dressed. The quoins are shown at a, and the body of the wall at b. The drawings for public and office buildings usually show every stone, unless broken ashlar is used, in which case it is only necessary to show the quoins and jambs, together with enough of the ashlar to indicate the character of the work desired.
It is only on works of great importance and solidity that ashlar masonry is used throughout the whole thickness of the wall. Both stone and brick are used as backing. When using brick for the backing, the joints should be made as thin as possible, employing cement mortar so as to avoid shrinkage.
Backing of this kind, however, should never be less than 8 inches thick. All backing, whether or brick or of stone, should be carried up at the same time and built in courses of the same thickness as the ashlar.
In such cases, each piece of ashlar should be tied to the backing by at least one iron clamp, or anchor, similar to that shown in fig.
Belt courses extending 8 inches or more into the wall should also be laid about every 6 feet in height, so as to give support to the ashlar.
For this reason, it is customary to refill the joints to a depth of from 1/2 to 1 inch, with specially prepared mortar. In work that is to be pointed, no mortar should be placed within an inch of the front edges of the stone, as this saves raking out the joints preparatory to the pointing.
Then, in setting the stone, the superfluous mortar is pressed out and the stone rests on the wooden strips, which are removed when the mortar is hard.
This may be done by scrubbing the stonework with water containing muriatic acid, the proportions being about 20 parts of water to 1 part acid.
The stonework should be scrubbed until all mortar stains are removed. Even fine carvings have been very successfully cleaned by this method. Attention must also be paid to securing uniformity of color as sandstone from different parts of the same quarry may vary greatly in this respect.
Frequently, the ends of cornices, belt courses, etc. It should be strictly required that the utmost care be taken in cutting all similar pieces to the same pattern, and that the abutting surfaces be closely dressed.
types of stone masonry. pptx
The bed joints in ashlar work should be square to the face of the work, and not less than 4 inches wide at both top and bottom.
Many other precautions for the good performance of the work will be doubtless suggest themselves to the careful superintendent. The stones for such work should be of good quality, having the beds closely dressed and the ends square and properly matched. When a brick building is trimmed with stone, great care should be taken to have the trimmings set properly, so that it will not be necessary to split the courses of brick below or above, for such a procedure will spoil the appearance of the building.
It is better, however, to make templates too large rather than too small. When a wooden girder rests on a templet, a good plan is to place a flat stone above the end of the girder so that the wall will rest on the stone and not on the wood.
Sometimes, the quoins of a rubble-stone wall are built of brick. The jamb stones bonding into the wall transversely are shown at a; those bonding longitudinally, at b; the stone window sill, at c; and the rubble wall, at d.
Jambs and quoins are often finished with a draft, or angle, line, especially when the softer stones are used. There should be a little play allowed at each end, so that the lintels can yield slightly without cracking if the walls on either side settle unevenly.
To avoid this result, if a stone of sufficient depth cannot be used, the lintel may be strengthened by the use of iron beams or angles.
It is sometimes necessary to use a stone lintel that is 10 or 12 feet long. At least three stones should be used, and the joints should be cut as shown at a. The end pieces may be built into the wall for a considerable length, so as to act as cantilevers supporting the middle section. In stonework it is best to avoid placing a pier directly on top of the lintel. Lug sills have flat ends, or lugs, built into the wall. If a sill is bedded solid and settlement occurs, it will probably be fractured at the jamb line, as the pier or side walls will likely settle more than the wall under the opening.
Slip sills are made just the width of the opening, and are not built into the walls, being put in place after the frame is set.
Besides, there are exposed vertical joints at the ends into which water will penetrate. They sometimes have a beveled surface the full length of the sill, the brickwork being made to fit the stone. Terra cotta is also occasionally used for this purpose. The coping should be about 3 or 4 inches wider than the wall. The bottom stone b, sometimes known as the kneeler, should always be well bonded into the wall. Each step should overlap the one below at least 1 1/2 inches, and should have an outward pitch of about 1./2 inch. Fig 47, make a good appearance, but they are more expensive than the ordinary steps. As shown at a, the landing is bappetted into the tread of the top step. To be safe, the bearing dimensions should not be less than are indicated in the illustration. The stone blocks forming the steps are usually cut in the triangular crossection shown, which method of cutting gives a good appearance to the soffit, or ramp, of the stairs.
Iron staircases are extensively used in fireproof construction. Staircase railings for stairways having stone or iron steps are often elaborately finished.
Rough Dressing And Ashlar Masonry