Spring is upon us and you may be thinking of repairing that winter masonry damage, or sprucing the masonry in your back yard. Here are some things you should know…
When your brick building has been painted.
Exposing the brick is the best option. People think that they need paint to protect the brick, or to make it look new again, but the fact is paint holds moisture in the brick which freezes and causes the brick to spall (the face of the brick cracks and falls off) and weakens the joints.Additionally, cracked paint can actually funnel rain water into your building. Also, moisture from the inside of the house is attracted to the outside through the brick via wick action (wet areas move towards dry areas in an attempt to equalize the air pressure) which can be trapped in the bricks if they are painted. If you do paint the brick, you have to use a breathable paint coating like Proseco (201) 754-4410 (South Plainfield, NJ) or you can stucco the brick (don’t use a slurry coating which cann’t be removed in the future) which is also breathable like brick.
Even breathable paint coatings have their drawbacks: to keep the facade looking good you’ll have to repaint it every 7 years, while a good brick cleaning and repointing will last 20 years. This means in 20 years you’ll have to paint your building 3 times. Brick is a natural masonry unit and inherently should not be painted.
People who have painted their brick do so to make the building look clean. This short term and cheap solution eventually cost more in repainting, time spent to paint and damage done to the facade due to trapped moisture. Also, brick does not need protection like wood does. Wood can rot after a couple of years if not protected while brick can last for centuries. Rome has brick that is exposed to the elements and has lasted over 2 thousand years.
Color: Understand your buildings’ basic color scheme, that is, look at the natural colors of your building before choosing color for trim. Essentially, you want a 3 color scheme for your building. 1) the brick color, 2) the lintels, sills and other stone/stucco color, 3) the trim color. Never use white for trim or window replacement for a masonry building because it looks cheap, gets dirty quickly, is too contrasty with its surrounds and makes the building look frail. Instead choose a medium to dark gray (with a hint of color) which will make your building look more uniform and solid. This color can also be used for the cornice. Always test your color on the actual surface before purchasing all your paint. You’ll find that the color looks substantially different in reality than in the store. This is known as ‘color change’. I would recommend mixing your own acrylic (or gauche) paint samples, 6″ x 6″ chips, and temporarily afix them to the building. Once you have the color you like, take the sample chip to the paint store, have them scan it into their computer and produce your custom color.
Mixing Colors to Make Samples: 1) Color has Saturation, that is how intense the primary color pigment is, 2) Color hasValue, that is, is the color closer to white, in the middle or closer to black, 3) Color has Hue, that is, is the color red, green, blue, etc. All colors have special relationships to other colors. In effect there are millions of colors to choose from and possibly trillions of relationships. This is why testing color relationships with samples is so important. Use de-saturated colors, with medium to darker Value, with complimentary or close to complimentary colors. If you understand these concepts, then you can make several attempts at choosing a color for your trim. If you don’t understand these concepts, then get help. An interior designer or Architect would be happy to lend a hand.
Cleaning: The brick should be cleaned using a chemical paint remover. High pressure water hosing should be used as a last resort in that it may damage soft (orangish) brick. Instead, the chemical should be rinsed off and more chemical should be applied. If applied properly, environmentally friendly chemicals can remove up to 12 layers of paint.
Joint Cleaning: Loose material and grout should be removed from the joints between bricks using a hand tool. The joints should not be mechanically cleaned in that this might damage the brick. Replace any loose or cracked bricks with bricks of similar color and texture. Remove all loose material.
Repointing: use 1 part Lime, 3 parts Cement and 6 parts Sand (Type 00). This will give you the consistency that is good for porous brick like ours is. Don’t use Sacrete, the mix should be done on site. There are pre-mixed lime mortars on the market but the tend to be more expensive. Don’t use white as your color, instead choose a gray which will bring out the natural beauty of your brick. Make sure your cement will not leach and stain your refinished brick after it has been finished.
Specific Requirements are as follows:
Prepare brick joints; provide new mortars with the right color; repoint brick joints and tool to match existing profiles; and, clean up finished work and remove debris from site.
1.02 Environmental Requirements: Concrete work must have a 48 hour window of non-freezing temperatures and another 24 hours for curing (drying). No work shall begin when any part of the wall, or materials in use are frozen, or subject to freezing temperatures. Cold weather construction shall adhere to the published guidelines in “Cold Weather Masonry Construction and Protection Requirements,” Brick Institute of America, latest edition. Materials shall be used only at the manufacturer’s recommended temperature tolerances for masonry materials. The work shall be protected during hot weather from premature or rapid curing by the use of dampened fabric coverings.
1.03 Product Handling and Storage: Store cement, lime, and aggregates in such a manner as to prevent deterioration or intrusion of foreign materials. Deliver materials in palletized containers, clearly labeled with manufacturer’s name, address and product identification. Store materials in original containers, protected from direct ground contact and inclement weather.
2.01 Materials: White Portland Cement: Type I, ASTM C-150 (white). (And,) Portland Cement: Type I or Type II, ASTM C-150 (gray). Hydrated Lime: ASTM C-207, Type S. Sand: Clean sharp sand free of loam, silt, soluble salts and organic matter, ASTM C-144. Water shall be potable (drinkable), from city mains. Oxide pigments (to color mortar) shall be stable, non-fading, and alkali resistant.
2.02 Mortar Mixes: Type N Mortar for Repointing: 1 part by volume white Portland cement & 1 part gray Portland cement. 0.5 parts by volume hydrated lime (Type S) & 8.5 parts “O” sand. Oxide pigments as needed to create approved mortar color.
2.03 Mixing of Mortar: Measure mortar ingredients carefully. Mix mortar in an approved power operated batch mixer. Mixing time shall be such as to produce a homogeneous plastic mortar, but not be less than five minutes, approximately two minutes of which shall be for mixing the dry materials and not less than three minutes for continuing the mixing after water has been added. A minimum amount of water shall be used to produce a workable consistency for the mortars intended purpose. Where mortar is required in small batches, mix by hand in clean wooden or metal boxes prepared for that purpose. Do not mix mortar on slabs, sidewalks, etc. After mixing, pointing mortars shall sit for 20 minutes prior to use to allow for initial shrinkage. Place mortar in final position within two hours of mixing. Retempering (adding water to) of partially hardened material is not permitted.
Execution: Raking & Re-pointing Existing Brick: Rake joints to a minimum 3/4″ depth. Remove all weathered and loose material. Remove all mortar from the surface of the brick within the joint so that new mortar bonds directly to brick. Do not damage brick faces and arises during the process of raking out or repointing. Brush raked joints to remove all mortar and foreign material. Wet brick at least 1 hour before pointing. No freestanding water shall be in joints during pointing operation. Add sand pile to base of facade for easy cleanup. Apply pointing mortar tightly in layers of 1/4″ to fill joint to match original sound joints. Construct uniform joints. Tool joints after final layer is “thumbprint hard” with a flat rule joint. Keep joints damp for at least 48 hours.
Cleaning of Masonry: Before the final setting of mortar, remove excess mortar and stains from the face of brickwork with dry, stiff bristle fiber brushes (no wire brushes allowed). Keep walls clean as work progresses. After mortar has cured, perform final cleaning, using clean water only and stiff fiber brushes. During cleaning, examine all joints in the work to locate cracks, holes and other defects and carefully point up such defects. If necessary, cut out joints and refill with pointing mortar.
Credit: The above outline of methods and materials was furnished by Jay Cardinal Building Conservation [(212) 580-9310]. When your building is a landmark building or you want it treated like a landmark, call the expert, Jay Cardinal Building Conservator.
Metal: Any metal which is in contact with masonry should be primed, painted and maintained so rust streaks do not occur on the masonry. These two materials should be separated at the outermost face with a dark gray silicon caulking on a foam backer rod (if required)
Lintels and Sills: These should be cleaned like the brick since they too are masonry. If they are damaged beyond salvage, then they should be replaced. Lintels should protrude beyond the face of the masonry and be set into the masonry at the sides. They should also be sloped to allow water to run off and drip free of the masonry facade.
Cornice: Have any rotted wood removed and replaced with pre-treated wood, mechanically fastened, spliced and primed. Rough wood surfaces can be smoothed with an epoxy compound, sanded smooth and primed before painting. Scratch the surface with sandpaper before repainting to create a better bond of the new paint with the old. Use a paint that is consistent with what is existing unless all the paint is removed, which, then, you can use a latex paint to finish. Choose deep dark colors which are consistent with the color scheme of your house.
Color tip: always ‘tone-down’ your color with gray. Woods, stone and other natural material don’t look good with bright colors.
Lighting Tip: Don’t use fixtures (or bulbs) which create a ‘light bomb’ or intense glare at night. Concentrate on lighting surfaces and not on lighting the sky, or space directly horizontal of the fixture. Light should be pointed at surfaces, this will allow neighbors to notice intruders easier than if they have to look into a ‘light-bomb’. It will also make your house look more attractive.
Last bit of advice: Hire a reputable contractor who understands these points and who has a reputation to protect. With that, they will do a good job.
Get several bids to see if your estimate is enough. If the first bid comes in much higher than your estimate, then tell the other contractors what your budget is and ask them what their recommendations are to get a professional result. Perhaps it is better to do a professional job on part of your building now and save the rest of the work for later.
Make sure they have a contract which spells out the work to be performed, the manner in which it will be performed (as outlined above), the materials used to perform the work, the time in which it will be completed and that they will leave the surrounding area as clean as when they started the work. Also, make sure the get any required Building Permits. Building Permits 1) insure that your contractor is insured so that you will not get sued if there is a problem, and 2) that the contractor is performing their work up to code (which is a minimum standard). Make sure that safety is their highest priority, no work will be done on your job if there is an injury and, no work is worth an injury. Make sure their workers have experience and if an individual doesn’t have experience, then make sure they are directly supervised by someone who does have experience.
Make sure your contractor is licensed, listed in the phone book with an address, and, is easily accessible (do you constantly speak to an answering machine, if so, don’t hire them because they may decide not to call you back). Pay for only work completed. Withhold the final payment until you are completely satisfied that all of the work has been performed as specified in the contract. A good contractor will inform you when a payment is required and why.
Simply put, there is a lot involved in getting a professional job done right. Take the time to properly manage and organize your effort so that you can avoid surprises, changes, cost overruns, and delays. Those are the things night-mares are made of and only your preparation can prevent them.
The reader should understand that SimpleTwig and its agents have no liability with the above ‘self-help’ categories and topics and that the owner assumes total responsibility for their own endeavor(s). These suggestions are given in the spirit of one friend asking another friend for advice. Because technology, context, and market changes from project to project, this advice is general in scope and should be verified with a qualified contractor, conservator, or Architect for your specific project. The intent here is to give the layperson some of the vocabulary and topics they should be concerned with when undertaking any Architectural project.
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