2. Inspecting the stone.

Inspect the lintel stone and select the best face for the exterior and the best side for exposure over the window opening.

3. Measuring end bearings.

Lay off the distance between the jambs on the lintel stone, allowing for equal space for lintel to rest on bed on each end.

4. Making bed.

FIG. 8.-Tudor arch type of lintel

(a) Place mortar bed on each pier.

This operation, as to the actual making of the bed, differs only slightly from that already described in the setting of sills.

(b) Wooden wedges if used should be placed in the mortar bed before setting the stone lintel.

FIG. 9. Colonial type of one piece lintel

5. Setting the stone.

(a) Lift the stone and carefully place in position on jamb piers. Because of the weight of stone lintels it is seldom that one person is required to set it. Especially is it desirable for two to place a lintel on its bed so that it will be unnecessary to move it on the bearing after it has once been dropped into position. Sometimes the lintel stone is heavy enough to require the help of a third man in lifting the stone while it is being placed on the bed. Usually, however, when a stone is very heavy, it will be lifted with a gin pole or a stiff-legged derrick.

(b) Plumb and tamp in place.

6. Parging the back.

Parge with nonstaining mortar the back of lintel before the brick. arch, steel angles, or channels and beams used for the support of backing masonry are set in place.

CAUTIONS

1. Avoid bedding ends of lintel stone until the mortar in the brickwork under the bearing has hardened sufficiently to support the weight of lintel stones.

2. Where window frames have not already been set and built in the openings provided for them, do not set lintel stone until the exact height of the window frame from bottom of wood sill to top of frame is known.

3. Do not set lintel in a manner that will result in its weight resting on the window frame.

4. A stone lintel should always be set on a bed of mortar the full area of bearing and the bed struck off flush, the pointing of the masonry being done at the time of setting so as to secure a solid bearing.

5. In the making of a mortar bed for lintels it is advisable to use a little stiffer mortar than that used for setting sills.

6. If the lintel stone is of considerable height, and especially where slow-setting lime mortars are being used, it is often advisable to stay the lintel in place by means of a simply constructed wood brace, thus preventing the lintel from overturning.

QUESTIONS

1. What provision is made for carrying the back wall above the lintel?

2. When is it advisable to use a rowlock relieving arch?

3. What is the purpose of wooden wedges and when should they be used?

Technical information sheet

JOB NO. 4

Block-BL-III: Jobs calling for the setting of (architectural terra-cotta and) cut-stone trim.

Job specification 2-A: Setting one-piece cut-stone trim on brickwork.

Type job a: Technical information relating to the setting of onepiece cut-stone lintels.

PRELIMINARY

Cut-stone lintels in brick walls, except where lined up with band courses or otherwise treated as band trim, are used principally for

53622-27-3

the structural purpose of spanning openings over windows and doorways, these openings being of ordinary width, the lintels carrying the weight of the brick masonry above.

1. Methods of supporting brick or tile backing.

STONE
LINTRI
WOOD

RELIEVING
ARCH

-BRICK ARCHE

Figure 10 is an isometric view showing in detail the use of wood centers for supporting the relieving arch back of a stone lintel during the process of construction. It also illustrates how these wood centers are constructed and the amount of bearing allowed over window frames. In practice the carpenter builds these centers and the bricklayer may assist him in setting them in place, or, if necessary, may set them alone.

Figure 11 is a sectional view showing rowlock arch in position over temporary centering. Where beams bearing on walls or other concentrated loads do not

122

11⁄2 OF BEARING IS ABOUT
ALL THAT IS USUALLY
PROVIDED OVER
ORDINARY WINDOWS.

DETAIL SHOWING WOOD CENTERS
FOR RELIEVING ARCH BACK
OF STONE, LINTEL
occur over the windows,
it is not necessary to
supplement the support
with steel, the custom-
ary practice being to
turn the rowlock arch
back of the stone lin-
tel, illustrated above.
Where the opening is
too wide to be spanned
by the stone as a struc-
tural member, the stone
lintel may be cut in three or more sections and be checked out at
the back to fit on the supporting member composed of a steel beam
of channel or angle sections. The stones are then fastened by means
of anchors.

CENTERS CONSIST OF TWO
HEAVY BOARD SEGMENTS
WITH STRIPS NAILED ACROSS

FIG. 10.-Isometric view of stone lintel showing row-
lock arch built over wood centering

Figure 12 ilustrates how a stone lintel is checked out and supported by an I beam and plate and anchored into the brick backing.

Figure 13 is an isometric view of a steel lintel supporting the backing wall, the stone lintel carrying only the face of the wall.

2. Use of wooden wedges.

Wooden wedges are often used in the setting of lintels. They prevent the squeezing out of mortar and the tipping over of the lintel stone caused

should be used for this purpose, so that upon the drying out of the mortar these wedges will shrink and become loose, permitting their

easy removal without

damage to the stone. These wedges should be

small in area, so as not

to reduce to any extent the surface of the mortar bed.

QUESTIONS

1. Describe briefly the different methods used in supporting brick backing.

2. What is the purpose of parging the back of stone lintels?

3. Of what material are anchors usually made?

REFERENCES

STONE LINTE

JOIST

STEEL LINTEL ISOMETRIC VIEW OF STONE LINTEL WITH STEEL LINTEL IN BACK FOR SUPPORT OF BRICK BACKING

The explanation of FIG. 13.-Sectional and isometric views of a stone

working drawings found

in Section II of this

lintel, showing use of steel angles for the support of brickwork

bulletin will assist in interpreting the drawings found in the lesson sheet.

Job outline sheet

JOB No. 5

Block-BL-III: Jobs calling for the setting of (architectural terracotta and) cut-stone trim.

Job specification 4: Setting several pieces of stone trim with end

DAMP PROOF COURSE OF
APPROVED WATERPROOF-
ING MATERIAL OR OTHER
IMPERVIOUS MATERIAL

FIG. 14. Sectional views of plain
grade courses

Grade courses are usually of two types. One of these is a plain course consisting of slabs of stone of required height, usually of the same thickness. The outer course of brickwork usually covers the thickness of the grade course. Such courses are usually from.14 to 20 inches in height, as illustrated in Figure 14.

The other type of base course is where the stone has a greater thickness than the width of a course of brick. This additional thickness serves as an intake in the thickness of the wall above the foundation, the top surface of the projecting stone being beveled off with