The lower course of arched openings in this photograph consists of bonded elliptical arches with a keystone. The windows above this lower...

<p>Terracotta has been used for thousands of years. In simple terms, terracotta is low-fired clay. &nbsp;</p>

<p>Header failures are not rare in the 100+-year-old masonry construction of Capitol Hill. In some cases, the reason for failure is as simple as natural deterioration with age. In other cases, contractors who did not know about working with historic materials have used the wrong materials and it actually accelerated the degradation of parts of [&hellip;]</p>

<p>In the photo below, you can see a double-wythe brick wall cut right down the middle. So, what is a wythe? Wictionary.com says EtymologyEdit Middle English from Old English withthe(“withe”) A wythe of brick is a single vertical assembly of units.  In this case, and typical with above grade exterior or even interior demising walls in Capitol Hill [&hellip;]</p>

<p>Oftentimes, what is otherwise just simple brick can be used in many ways in our Capitol Hill historic façades to provide variation and accent. Brick set at an angle so you can see both the soldier and sailor faces or the spreader and shiner faces at the same time is called &#8220;cogging.&#8221; Between a window [&hellip;]</p>

<p>Roman Brick is long and thin. It is found in a few places in DC and it is rarely not covered in paint. This house is built with a beautiful example of Roman brick, left unpainted.</p>

Tudor Style Arches used in the construction of a historic church here in Capitol Hill

<p>From left to right&#8230;.</p>

<p>The photo below shows a precast CMU coping unit (not actual stone) used in a mid-century building in Capitol Hill.</p>

<p>Ashlar masonry quoin corners are found at a handful of buildings here in Capitol Hill. Masonry structure corners provide significant structural strength.  Quoin corners can be built with accent brick, cement units, ashlar stone (such as in the following picture) and even with rubble stone. Click here to go to the list of all items [&hellip;]</p>

<p>Jack Arches are common in Capitol Hill.  They work well with a tall rectangular window with the inside of the window close to the underside of the ceiling on the interior side of the building. Jack arches are also sometimes referred to as &#8220;flat arches&#8221; or &#8220;straight arches.&#8221; A jack arch is an alternative to [&hellip;]</p>

<p>Sometimes called &#8220;Rubble Masonry,&#8221; non-ashlar consists of laying material that is not uniform — in most cases, different sizes and shapes of stone set in mortar.  Many historic foundations are built using this technique. However, the homes on Capitol Hill built in the late 19th century and on were primarily brick. Historic rubble foundations were [&hellip;]</p>

<p>Advantages of Brick Does not burn Raw materials are cheap, making it economical to produce Reusable Versatile size, shape, and texture High compressive strength Low maintenance &nbsp; Disadvantages of Brick Time-consuming building process Poor seismic rating Prone to efflorescence due to moisture permeability Low tensile strength Click here to go to the list of all items [&hellip;]</p>

<p>In general terms —between masons — a thinner mortar joint is a sign of higher quality work, but require higher labor and skill. In comparable terms, mortar is cheaper than the masonry unit. So sloppy wide mortar joints are cheap, while thin and neat mortar joints are expensive. In Capitol Hill, the front façades are [&hellip;]</p>

<p>Capitol Hill is home to many historic retaining walls built from brick or stone. Many homes with English Basements have a lower entrance that is sidewalk level and/or feature a raised garden in between the door and the sidewalk. Hydrostatic pressure often builds behind these walls and, with nowhere to go, can start to damage [&hellip;]</p>

<p>Spalling occurs when hydrostatic pressure builds up behind a brick wall, allowing too much moisture permeance. The water is absorbed into the brick and, because of variations in temperature and pressure, the water expands. This expansion can causing flaking, cracking, or even bricks that become split entirely. Click Here to Go to the List of All [&hellip;]</p>

<p>The vast majority of the buildings in the historic parts of Capitol Hill are built with &#8220;frog-less&#8221; bricks. It is said that the slop molds which were once used to create bricks in the mold making process, with an indentation set in, look like a frog with its legs at its side and its torso [&hellip;]</p>

<p>A Bat Brick is a brick cut across the width, shortening the length of the brick.  A brick cut to 3/4 the length is a 3/4-bat; similarly, a brick cut in half is a half-bat. A Bat Closer is used at the end of the brick course to end the row but still make a [&hellip;]</p>

<p>Brick corbelling is a pattern that sets subsequent courses extending out from the planar surface of a wall. The technique allows the lower courses to support the courses above which jut further out, though typically it is constructed for purely aesthetic reasons. Around Capitol Hill, corbelling is typically seen at the tops of row homes, [&hellip;]</p>

<p>During the construction of most Capitol Hill row homes at the turn of the 20th Century, modern strong mortar was not available to brick and stone masons. Our modern Portland cement has only been recently used for a short period of time for masonry construction (in America). Prior to portland cement, lime and sand were [&hellip;]</p>