The elements of brick masonry include: BRICKS & MORTAR
Masonry is a key element in defining the character for historic buildings. The texture and patters of brickwork. Much more advance planning is required for successful masonry repairs to historic structures than is normally necessary for the maintenance of contemporary masonry buildings.
The key to successful maintenance of historic masonry is understanding the materials and methods of original construction and carefully evaluating the cause of deterioration.
Masonry problems occur in area that are heavily exposed to moisture or significant temperature fluctuation. Some common places are:
- Masonry Cleaning- This is the first step for improvement and usually the least important requirement for proper maintenance. Cleaning may be a necessary part of a larger repair project that involves re-pointing or replacement of a damaged section of a wall. Please note, harsh cleaning may also damage the historic masonry. Specifications for cleaning historic masonry often calls for the use of nonionic detergents that avoid using harmful chemicals into masonry. One key suggestion is to test a small area prior to taking on the full job.
- Repointing or Tuck-pointing– is the raking and refilling of the outer face of the mortar joints. Properly done, and undertaken when needed, can prevent moisture infiltration.
- Caulk and Sealants- Frequently caulking and sealants are inappropriately used for sealing joints when mortar should be used. Sealants are appropriate to use where masonry abuts wood or metal such as around window frames.
- Repair and Replacement of Deteriorated Stone and Brick– It may be necessary to replace or repair seriously damaged individual bricks to ensure that the wall remains . It is important to be considerate to the size and type of brick when replacing the existing damaged one.
Mortar and Erosion and Mortar Deterioration
What is mortar?
Most basically, it joins the irregular surfaces of the masonry units and to keep water out of the masonry. Masonry mortars can be lime-based or Portland cement-based and, to confuse matters, some mortars may be combinations of the two.If you are hiring a mason to do repair work, ask him questions about the mix he is going to use and, more importantly, ask him why. Have him point a small area (perhaps a couple square feet) so you can evaluate the color match. With the information you have collected about your house, you should be in a good position to discuss the most appropriate formulation. Don’t be afraid to insist on a softer mortar.
Some types of Mortar:
(note your contractor or architect can advise you specifically on this)
- Type N is of medium strength, which means it is the best choice for projects with bricks that are not load bearing. Garden walls, chimneys, and barbecues are common applications for this mix. Type N is also preferred for soft stone masonry. This is the mortar most often used by home owners. It is easy to work with and is appropriate for most brick projects that the typical home owner would attempt.
- Type S is known for its strength and is used outdoors. Patios, foundations, and retaining walls all use Type S. It is used for its ability to absorb most impacts. It is still an easy product to work with, but homeowners should have some experience working with brick before beginning any type of project that requires this product.
- Type M is the strongest mix that you will find in a home improvement store, Type M is typically used only with stone. Type M is preferred with stone because the strength of the mortar typically mimics that of the stone being used. It is also used in situations where being able to bear heavy loads are important, such as retaining walls.
Key words to know when looking compromised brick
Is similar recyrstallization of soluble salts beneath the surface of masonry. It often occurs in conjunction with efflorescence and may seriously damage the masonry units by causing the surface to spall or flake away. Here is an excellent diagram from Building Science Information’s website:
One key component to consider is that repointing or aqueous cleaning should be done when there is no danger of freezing. It is prudent to restrict work to seasons when the night temperature will not fall below 40 degrees. Freezing of wet mortar damages it and dramatically reduces its durability while wet pours stone and brick are susceptible to damage from frost spalling.
There are many resources out there that can explain the facts and myths of the replace vs. restore historic windows debate. Despite the bad rap windows account for only 10-15% of energy lost through mostly air filtration. One thing to do is to make sure your windows fit tightly by repairing them and adding weather-stripping, interior or exterior storms and interior window treatments.
According to the Weatherization Tool Kit by the Division for Historic Preservation, they suggest avoiding replacing historic windows with new windows. You may find asking yourself why bother because of all the extra time and effort it takes.
But here are some reasons that will encourage you to restore your historic windows:
- Replacement windows are often more expensive, they have a limited life span.
- Replacement windows can change the character of your historic home.
If you live in a Historic District in Albany you should check with the Historic Resources Commission (HRC) to follow their suggested protocol. It is important to be aware of what we talked about way back in the first post. Check with your local agencies!
Here is a diagram of common windows to historic buildings found through NY State:
The key component is to think about each individual window. Creating a survey system of each window and door will be really helpful. Simply rate the windows (poor, fair, good, excellent) Once you have a survey of each window you can account for the individual circumstances of each one.
Common Problems with historic windows:
- Sticky Windows/ Loose Windows
- Replacing Glazing and Putty
- Sash Cords and Weights
- Cracked Paint: If your house was built prior to 1978, trim and window elements likely contain lead. See Environment Protection Agency for regulation
Here is a diagram from the Division for Historic Preservation NY State Office of Parks, Recreation and Historic Preservation of where the air infiltration occurs most often:
A. Weather-stripping should be installed at the jambs, the sill, the head and the meeting rails. Use a thin putty knife to slip behind the stop and lightly pry off. This will allow you to remove the sash and install spring bronze.
B. Spring bronze is a good choice for the jambs. The strip is nailed to the jamb channel along the interior side of the stop or parting bead.
C. An interlocking strip is best for the meeting rails. When the window is closed, the strips close off any air gaps. The sash lock pulls the meeting rails tight.
Here is six minute video from Mac Bagala called Window Restoration 101. The video outlines the process involved in restoring a historic window. He has even included a soundtrack for your enjoyment. I really enjoyed seeing the entire process and while we often just want to get our windows un-stuck and opened, I can now see the patience and craftsmanship involved in restoring old wooden windows.
Here are further resources for your use:
Embracing Energy Efficiency
PRESERVATION: Closing the door on vinyl windows
What Replacement Windows Can’t Replace
Seven to Save Endangered Property List, 2006 Original and Historic Wood Windows Repair and Preservation
Brochures & Guides
We have a list of local specialists in Albany that we’d be happy to share with you.
Please contact us if you have any further questions.
Congratulations! You now have a historic home in Albany, NY that is in a historic district. If you are in question about your district, please refer to the Historic District Map from the Historic Resources Commissions website.
What does that mean and how will that impact you?
The best case scenario is that your home is in perfect condition and the previous owner has updated everything beautifully and you are in the clear. That is wishful thinking. There is always a window that may need replacing or exterior painting that needs updating. The main thing to think about as you begin to look closely at the challenges ahead on fixing your property is that you will have play by the rules. By this point, you have already acknowledged the property’s importance to its community, state and some people will argue to the NATION. However the initial impact for you can seem costly and time-consuming, but there are resources that can help you through the process. This goes without stating, Historic Albany Foundation can always guide you through these steps.
There are a few resources affiliated with the City of Albany to know about as you move forward
(be sure to click on the underlined portion)
So what are the next steps?
Here is a great resource put together by Preservation League of NY State.