Today we will discuss some of the top FAQâs for historic brick tuckpointing or repointing for buildings like the historic row homes of Washington, DC Today, we will answer five specific FAQâs focused on the following topics: This week we are covering some of the most common FAQs that we receive from our clients about repointing. You can learn a lot from the discussion that developed around these questions. 1.What is masonry pointing, tuck pointing, or repointing, and why is it crucial for historic row homes in Washington DC?Tuck pointing or repointing is a commonly needed brick or stone masonry restoration process used to preserve and extend the longevity of historic row homes in Washington DC. This detailed process requires the removal of deteriorated or compromised mortar from the joints between bricks or stones at a buildingâs exterior facade. The weathered mortar is then replaced with fresh, compatible mortar that closely adheres to the original mortarâs composition in terms of functional properties or characteristics. Aesthetics like color and mortar texture are also considered, but the number one important factor is the structural aspects of the mortar. Over time, the erosive influence of natural elements, such as precipitation and resultant hydration, and freeze-thaw cycles can significantly weaken the mortar, thereby creating or expanding gaps and cracks that directly compromise the facadeâs overall strength and its ability to withstand the continued ongoing impact of external forces. The picture below shows an example of a wall that was repointed in recent years with fresh mortar. The stone has a higher compressive strength and lower permeability than historic brickwork, but this facade was repointed with a mortar that works in relative compatibility with the stonework. Although this particular wall has been repointed, the work was not done by our company and our company would be remiss to not point out that there are defects in this work. Our company happens to have a high standard of quality control; we would not accept this work as properly complete. In a photo below we show a close up view of the mortar joint and you can see there is a concave nature to this particular joint. The concave nature of this mortar joint is exaggerated and elongated excessively and would not be acceptable in the quality standards of our company. A rake joint is intended to be recessed inside of the outer face of the masonry units of the wall, there is a rake joint at this location but the rake joint does not finish in a close to plumb or vertical position. We consider that unacceptable. However, we are not alone in this technical perspective. The NPS preservation briefs related to historic masonry restorations explain that the more joint applied should be applied in a relatively consistent The NPS preservation briefs related to historic masonry restorations explain that the more joint applied should be applied in a relatively consistent or uniform application when recessed within the joint. A slightly concave or âbucket handleâ is only slightly concave and acceptable by comparison, but we recommend an even less concave flush joint aimiliar to the original installation, in most cases. It should be noted though that even a so called âflush joint is NOT perfectly flush and does have a slight recess. In conclusion, the important takeaway is that tuckpointing or repointing and overall general facade restoration, upkeep, maintenance and management of exterior brick building faces are very important, actually crucial, at this particular time because we are at the end of the first cycle of required pointing in the life period of the Capitol Hill buildings built around the time range between the late 19th century and the early 20th century. Without repointing or tuckpointing and significant restoration at this particular point in time, deterioration will continue but it will continue at an increasing rate. This increasing rate specifically means that as deterioration continues it will get worse and worse in shorter periods of time, at an exponentially increasing rate. 2. How does the local climate in Washington DC affect the need for repointing?The typical winter season freeze-thaw cycles in the Washington DC area can exacerbate issues associated with deteriorating historic masonry. Freeze-thaw cycles happen in more than just the three months of the winter season of the year, between December 21st or 22nd to March 20th or 21st, (the exact time and day of winter solstice and spring equinox vary a bit each year) in fact thereâs generally a range of about 5.75 months per year when freeze-thaw cycles fluctuating between warm temperatures during the day and cold temperatures at night, can affect historic brick masonry, in our area. (This time of potential freezing temperatures is from about October 21st to April 16th in our area, but abnormalities will continue to increase with global warming. Climate change is real and its happening and will continue to get significantly worse for years to come, regardless of the tempting arguments espoused and proliferated by climate change deniers.) These problems associated with freeze-thaw cycles and their deleterious effect on masonry only happen when the masonry is also affected by moisture. The typical concerns about moisture are related to precipitation, either in the form of regular rainfall, or snow, sleep, mist and other types of less typical precipitation. There is another type of moisture, though, which can affect masonry walls, in the form of condensation from temperature differentials between tempered indoor space and hot or cold outdoor space. Altogether then considering these two factors, both precipitation and condensation, thereâs two main types of moisture that typically affect masonry walls. By-and-large, the larger of these two factors is typical precipitation which we are all familiar with, but the way that precipitation affects historic masonry construction and walls may be a bit counterintuitive. We generally think of rain entering the surface of the brick, accumulating in loose or deteriorated more joints and then freezing, causing significant expansive pressures and forces from the change of water from a liquid to solid state. That typical most common type occurrence is definitely problematic, but water can also follow pathways into masonry that are less intuitive. The picture below shows an area of brick and mortar joints with biocolonization or plant growth on the surface of the mortar joint area. The pictures in the collage above shows an area of a brick masonry exterior wall where the historic lime mortar joints have experienced significant damage from exposure to moisture. Not just recently, but ongoingly for years, these particular joints have already degraded substantially and the inner line binder has significantly dissolved away from the aggregate and sand elements of the mortar joint. Where the plant growth occurs on the surface, deeper into the mortar joint there are capillaries, open and/or partially filled with the roots of the biocolonization and or plant growth. Water on the surface then will follow these pathways deeper into the mortar joint in effect increasing continued deterioration at an accelerated rate, in part because there are already plants growing on top of the mortar joints which will lead to increased deeper hydration. Essentially, the exposure to moisture on the outside of the wall has led to more moisture entry, even deeper, into the interior parts of the brick wall. Now that this damage has occurred water will freeze farther into the wall causing damage at an even deeper location and to a greater extent. This illustrates one of the many reasons that itâs important to be engaged in the care of a building and manage the care of the exterior facade of a historic brick building In a prompt and proactive way. 3. How frequently should repointing be performed to ensure the long-lasting preservation of a historic brick facade?The frequency of repointing in the maintenance of a historic brick facade is an important consideration, in understanding the buildingâs requirements for upkeep, maintenance, and preservation. The information provided by various âauthoritiesâ in the industry, varies widely. While there isnât a fixed timeframe for repointing, several factors contribute to determining the appropriate schedule for this needed process. The rate of deterioration in historic brick masonry hinges on various elements, including climate, exposure to moisture, the quality of the original mortar, and the level of maintenance. In regions like Washington DC with fluctuating weather patterns, extreme temperature variations, and high humidity levels, the impact of freeze-thaw cycles and moisture infiltration accelerates the degradation of mortar. This environmental stress highlights the importance of vigilant maintenance to ensure the long-lasting survival of historic brick facades. In general, it is advisable to conduct a thorough assessment of the mortarâs condition at least every 20 to 30 years. But, we actually recommend an annual assessment of exterior facade conditions,inclusive of much more than just the brick and mortar condition. An annual, overall favade conditions survey should include at least the following items:
Its important to consider all of the items above at least on a routine annusk basis; however, the time frame for specifically focusing just on brick and mortar joints can vary based on the several aforementioned factors. Some buildings may necessitate more frequent repointing, particularly if they face elevated levels of exposure to moisture or harsh weather conditions. Conversely, structures with less exposure may have a longer repointing interval, but dont expect less exposure in the Washington DC area, itâs uncommon. Visual cues play a crucial role in determining when repointing is required. Crumbling, cracking, or missing mortar joints, along with noticeable gaps between bricks, are signs of impending structural issues. Once your building has reached this point, that you can see gaps and voids, you should take action. Professional evaluation and expertise are indispensable in determining the appropriate timing for repointing. Engaging a qualified historic preservation specialist or masonry professional is crucial. They can provide an analysis of the buildingâs condition, considering aspects like mortar composition, bonding materials, and the broader context of its architectural significance. A comprehensive understanding of the historic fabric enables the development of a tailored maintenance strategy that aligns with preservation best practices and minimizes unnecessary intervention or deterioration past the point of maintenance optimality. In summary, repointing is not a one-size-fits-all endeavor, and its frequency should be determined on a case-by-case basis. While a general guideline suggests assessing the mortar every few decades, this interval depends on climate, exposure, original mortar quality, and the overall maintenance regimen. Regular inspections and professional consultation remain key to ensuring the structural integrity and historical continuity and competency of the brick facade. By striking the right balance, property owners can contribute to the long-lasting preservation of brick facades in the historic neighborhoods of Washington DC, like Capitol Hill. 4. Can I attempt repointing as a DIY project, or should I engage professionals?Yes, taking on a DIY repointing projects is a worthwhile endeavor for individuals interested in acquiring valuable skills and knowledge in the realm of brick restoration and repointing. At IDS, we wholeheartedly encourage everyone, regardless of experience, age, physical constitution (within reasonable limits), to explore the world of brick restoration and consider tackling such projects. You can keep it small to start and call in help where it is needed, but understand upfront that repointing, especially with historic masonry is not somethingyou can learn overnight, you need deep and extensive learning and study first. An excellent starting point to gather insights and information about brick restoration and repointing can be found on our blog at ids-dmv.com/blog. This comprehensive resource provides a wealth of information, tips, and techniques that can empower individuals to embark on DIY projects with a solid knowledge base. However, itâs important to recognize that all aspects of repointing demand specialized training, certification, and extensive study, particularly pertaining to safety, proper work practices, OSHA requirements, and environmental hazards. Before even starting any DIY work, we strongly advocate for a full commitment to understanding and adhering to safety guidelines, regulations, and recommendations. Prior to even contemplating undertaking actual work, itâs essential to arm oneself with a thorough understanding of safety protocols to ensure a DIY-erâs safety. While DIY repointing projects offer a great opportunity for self-learning and skill acquisition, itâs important to approach them with a responsible and informed perspective. Acquiring the necessary expertise, education, and training before undertaking repointing work ensures a safe and effective execution of the project. Itâs essential to combine enthusiasm with comprehensive preparation and adherence to safety protocols to guarantee a successful and secure DIY project. 5. Are there instances where repointing might not be the best solution for addressing deteriorating mortar?The answer is clearly and simply yes. Yes, itâs true, repointing is not always the solution for all historic masonry restoration or repair situations. There are several other classes and types of deterioration and or needed types of repair that are different and separate and or unrelated to just repointing. Repointing is very important , when the mortar joints between bricks become deteriorated in the natural aging process of masonry buildings, but There are tons of other types of problems that can occur and take place and need upkeep and maintenance related to historic masonry facades and or brick buildings. Cement, concrete, brick work, and masonry and mortar all experience deterioration and aging from exposure to the natural environment and external elements. The image below shows one of the chimneys from another image higher up in this same article, but in this particular case that chimney is compared to another chimney With a similar issue of near complete destabilization and failure. These chimneys are literally close to the point where they are ready to collapse. At the point when they do collapse, there will be significant damage to both the building and significant risk from the perspective of safety. The issue of structural failure at these chimneys originally started as a area of masonry that needed restoration and upkeep through repointing. Repointing could have literally stabilized these brick chimneys. However, at this point in time, the issue is far past the point where repointing alone can be helpful. At this point, that chimneys must be rebuilt. The adjacent image shows an example of a knee wall that has destabilized due to a compromised or insufficient footing underground. (Without excavation, we have no way to determine if the footing has been compromised by other forces such as adjacent excavation separate from its own construction, or if it was built undersized and excessively small. However, even though we donât really know the true answer, chances are very high that the footing was actually built excessively small, undersized. Itâs just an assumption, but based on past similar issues at front and rear porches at DC rowhomes, qe have overwhelmingly found post, puer, and kneewal footings were built unsized compared to modern standards and the needs to the structure.) The footing was either built at an insufficient depth and/or does not have sufficient capacity to support the kneewall. In relation to the adjacent main building facade, there is differential settlement which has caused the kneewall to move out of plane away from the rear facade wall of the main building. Differential settlement, lateral deflection, and header breakdown are types of structural failures. All of these items are at least related to mortar conditions and in some cases casual reactions or effects of unmitigated joint deterioration, in other words a result of not repointing at the needed time. However, repointing alone will not fix all of these issues. If repointing is not done when it is needed, in a reasonable time frame, the unmitigated mortar deterioration can lead to much more extensive issues. Once these more extensive problems take place and damage extends beyond the surface of a brick masonry facade, the problem is exacerbated and requires much more extensive repair, repairs that pointing or repointing or tuckpointing alone cannot fix. Next weekâs coming discussion In the coming week we will examine more details of historic brick masonry restoration and discuss some other interesting FAQâs. Some of those upcoming topics include the following:
To properly maintain, repair, and care for these historic buildings, a knowledge, interest and understanding of historic building principles is required. Here in Washington DC, historic masonry buildings are extremely expensive and the amount of financial loss caused by improper repointing and low quality construction is staggering. However, in addition to the direct financial value of the property, there is also a cultural loss when historic buildings are damaged. By comparison, consider neighboring poor cities, when historic buildings are damaged, itâs not just the loss of value to the property owner, thereâs also a loss to all inhabitants and visitors of a city, present and future, who care about architecture, history, and culture. We encourage all of our clients, and all readers of this article and to our blog in general, to prioritize the historic built environment of Washington DC and neighborhoods such as Capitol Hill, Dupont Circle, and Georgetown and become educated on on the difference between proper historic preservation versus improper work which leads to significant damage to the historic fabric of a building. From a conservation and preservation perspective, several approaches can be taken to improve conditions related to deteriorated historic brick masonry. Primarily, lime mortar brick joints and low temperature fired soft red clay bricks should be inspected and checked on a routine maintenance schedule, either seasonally or at least annually. If brick masonry is kept in good condition, the life of embedded wood elements can be significantly extended. Hire a professional contractor which specializes, understands and appreciates historic construction elements and buildings. You can learn a lot more on our blog. Feel free to check it out. If you have questions about the historic masonry of your building in Washington DC, contact us or fill out the webform below and drop us a line. We will be in touch if we can help. <p>The post Top Historic Masonry Repointing FAQs â Part I first appeared on Infinity Design Solutions.</p> Via https://www.ids-dmv.com/masonry/top-historic-masonry-repointing-faqs-part-i/
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About UsInfinity Design Solutions LLC (IDS) is a full service general contracting company in the heart of the Dupont Circle neighborhood of Washington, DC. We focus on repair and renovation of buildings and facilities in both historic designated neighborhoods and the commercial-zoned central business district of the city. Follow Us
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